some progress

node_modules/mongoose/lib/browser.js

@@ -0,0 +1,132 @@
+/* eslint-env browser */
+
+'use strict';
+
+require('./driver').set(require('./drivers/browser'));
+
+const DocumentProvider = require('./document_provider.js');
+
+DocumentProvider.setBrowser(true);
+
+/**
+ * The [MongooseError](#error_MongooseError) constructor.
+ *
+ * @method Error
+ * @api public
+ */
+
+exports.Error = require('./error/index');
+
+/**
+ * The Mongoose [Schema](#schema_Schema) constructor
+ *
+ * #### Example:
+ *
+ *     const mongoose = require('mongoose');
+ *     const Schema = mongoose.Schema;
+ *     const CatSchema = new Schema(..);
+ *
+ * @method Schema
+ * @api public
+ */
+
+exports.Schema = require('./schema');
+
+/**
+ * The various Mongoose Types.
+ *
+ * #### Example:
+ *
+ *     const mongoose = require('mongoose');
+ *     const array = mongoose.Types.Array;
+ *
+ * #### Types:
+ *
+ * - [Array](/docs/schematypes.html#arrays)
+ * - [Buffer](/docs/schematypes.html#buffers)
+ * - [Embedded](/docs/schematypes.html#schemas)
+ * - [DocumentArray](/docs/api/documentarraypath.html)
+ * - [Decimal128](/docs/api/mongoose.html#mongoose_Mongoose-Decimal128)
+ * - [ObjectId](/docs/schematypes.html#objectids)
+ * - [Map](/docs/schematypes.html#maps)
+ * - [Subdocument](/docs/schematypes.html#schemas)
+ *
+ * Using this exposed access to the `ObjectId` type, we can construct ids on demand.
+ *
+ *     const ObjectId = mongoose.Types.ObjectId;
+ *     const id1 = new ObjectId;
+ *
+ * @property Types
+ * @api public
+ */
+exports.Types = require('./types');
+
+/**
+ * The Mongoose [VirtualType](#virtualtype_VirtualType) constructor
+ *
+ * @method VirtualType
+ * @api public
+ */
+exports.VirtualType = require('./virtualtype');
+
+/**
+ * The various Mongoose SchemaTypes.
+ *
+ * #### Note:
+ *
+ * _Alias of mongoose.Schema.Types for backwards compatibility._
+ *
+ * @property SchemaTypes
+ * @see Schema.SchemaTypes #schema_Schema-Types
+ * @api public
+ */
+
+exports.SchemaType = require('./schematype.js');
+
+/**
+ * Internal utils
+ *
+ * @property utils
+ * @api private
+ */
+
+exports.utils = require('./utils.js');
+
+/**
+ * The Mongoose browser [Document](/api/document.html) constructor.
+ *
+ * @method Document
+ * @api public
+ */
+exports.Document = DocumentProvider();
+
+/**
+ * Return a new browser model. In the browser, a model is just
+ * a simplified document with a schema - it does **not** have
+ * functions like `findOne()`, etc.
+ *
+ * @method model
+ * @api public
+ * @param {String} name
+ * @param {Schema} schema
+ * @return Class
+ */
+exports.model = function(name, schema) {
+  class Model extends exports.Document {
+    constructor(obj, fields) {
+      super(obj, schema, fields);
+    }
+  }
+  Model.modelName = name;
+
+  return Model;
+};
+
+/*!
+ * Module exports.
+ */
+
+if (typeof window !== 'undefined') {
+  window.mongoose = module.exports;
+  window.Buffer = Buffer;
+}

node_modules/mongoose/lib/browserDocument.js

@@ -0,0 +1,101 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const NodeJSDocument = require('./document');
+const EventEmitter = require('events').EventEmitter;
+const MongooseError = require('./error/index');
+const Schema = require('./schema');
+const ObjectId = require('./types/objectid');
+const ValidationError = MongooseError.ValidationError;
+const applyHooks = require('./helpers/model/applyHooks');
+const isObject = require('./helpers/isObject');
+
+/**
+ * Document constructor.
+ *
+ * @param {Object} obj the values to set
+ * @param {Object} schema
+ * @param {Object} [fields] optional object containing the fields which were selected in the query returning this document and any populated paths data
+ * @param {Boolean} [skipId] bool, should we auto create an ObjectId _id
+ * @inherits NodeJS EventEmitter https://nodejs.org/api/events.html#class-eventemitter
+ * @event `init`: Emitted on a document after it has was retrieved from the db and fully hydrated by Mongoose.
+ * @event `save`: Emitted when the document is successfully saved
+ * @api private
+ */
+
+function Document(obj, schema, fields, skipId, skipInit) {
+  if (!(this instanceof Document)) {
+    return new Document(obj, schema, fields, skipId, skipInit);
+  }
+
+  if (isObject(schema) && !schema.instanceOfSchema) {
+    schema = new Schema(schema);
+  }
+
+  // When creating EmbeddedDocument, it already has the schema and he doesn't need the _id
+  schema = this.schema || schema;
+
+  // Generate ObjectId if it is missing, but it requires a scheme
+  if (!this.schema && schema.options._id) {
+    obj = obj || {};
+
+    if (obj._id === undefined) {
+      obj._id = new ObjectId();
+    }
+  }
+
+  if (!schema) {
+    throw new MongooseError.MissingSchemaError();
+  }
+
+  this.$__setSchema(schema);
+
+  NodeJSDocument.call(this, obj, fields, skipId, skipInit);
+
+  applyHooks(this, schema, { decorateDoc: true });
+
+  // apply methods
+  for (const m in schema.methods) {
+    this[m] = schema.methods[m];
+  }
+  // apply statics
+  for (const s in schema.statics) {
+    this[s] = schema.statics[s];
+  }
+}
+
+/*!
+ * Inherit from the NodeJS document
+ */
+
+Document.prototype = Object.create(NodeJSDocument.prototype);
+Document.prototype.constructor = Document;
+
+/*!
+ * ignore
+ */
+
+Document.events = new EventEmitter();
+
+/*!
+ * Browser doc exposes the event emitter API
+ */
+
+Document.$emitter = new EventEmitter();
+
+['on', 'once', 'emit', 'listeners', 'removeListener', 'setMaxListeners',
+  'removeAllListeners', 'addListener'].forEach(function(emitterFn) {
+  Document[emitterFn] = function() {
+    return Document.$emitter[emitterFn].apply(Document.$emitter, arguments);
+  };
+});
+
+/*!
+ * Module exports.
+ */
+
+Document.ValidationError = ValidationError;
+module.exports = exports = Document;

node_modules/mongoose/lib/cast.js

@@ -0,0 +1,402 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const CastError = require('./error/cast');
+const StrictModeError = require('./error/strict');
+const Types = require('./schema/index');
+const cast$expr = require('./helpers/query/cast$expr');
+const castTextSearch = require('./schema/operators/text');
+const get = require('./helpers/get');
+const getConstructorName = require('./helpers/getConstructorName');
+const getSchemaDiscriminatorByValue = require('./helpers/discriminator/getSchemaDiscriminatorByValue');
+const isOperator = require('./helpers/query/isOperator');
+const util = require('util');
+const isObject = require('./helpers/isObject');
+const isMongooseObject = require('./helpers/isMongooseObject');
+
+const ALLOWED_GEOWITHIN_GEOJSON_TYPES = ['Polygon', 'MultiPolygon'];
+
+/**
+ * Handles internal casting for query filters.
+ *
+ * @param {Schema} schema
+ * @param {Object} obj Object to cast
+ * @param {Object} [options] the query options
+ * @param {Boolean|"throw"} [options.strict] Wheter to enable all strict options
+ * @param {Boolean|"throw"} [options.strictQuery] Enable strict Queries
+ * @param {Boolean} [options.upsert]
+ * @param {Query} [context] passed to setters
+ * @api private
+ */
+module.exports = function cast(schema, obj, options, context) {
+  if (Array.isArray(obj)) {
+    throw new Error('Query filter must be an object, got an array ', util.inspect(obj));
+  }
+
+  if (obj == null) {
+    return obj;
+  }
+
+  if (schema != null && schema.discriminators != null && obj[schema.options.discriminatorKey] != null) {
+    schema = getSchemaDiscriminatorByValue(schema, obj[schema.options.discriminatorKey]) || schema;
+  }
+
+  const paths = Object.keys(obj);
+  let i = paths.length;
+  let _keys;
+  let any$conditionals;
+  let schematype;
+  let nested;
+  let path;
+  let type;
+  let val;
+
+  options = options || {};
+
+  while (i--) {
+    path = paths[i];
+    val = obj[path];
+
+    if (path === '$or' || path === '$nor' || path === '$and') {
+      if (!Array.isArray(val)) {
+        throw new CastError('Array', val, path);
+      }
+      for (let k = 0; k < val.length; ++k) {
+        if (val[k] == null || typeof val[k] !== 'object') {
+          throw new CastError('Object', val[k], path + '.' + k);
+        }
+        val[k] = cast(schema, val[k], options, context);
+      }
+    } else if (path === '$where') {
+      type = typeof val;
+
+      if (type !== 'string' && type !== 'function') {
+        throw new Error('Must have a string or function for $where');
+      }
+
+      if (type === 'function') {
+        obj[path] = val.toString();
+      }
+
+      continue;
+    } else if (path === '$expr') {
+      val = cast$expr(val, schema);
+      continue;
+    } else if (path === '$elemMatch') {
+      val = cast(schema, val, options, context);
+    } else if (path === '$text') {
+      val = castTextSearch(val, path);
+    } else {
+      if (!schema) {
+        // no casting for Mixed types
+        continue;
+      }
+
+      schematype = schema.path(path);
+
+      // Check for embedded discriminator paths
+      if (!schematype) {
+        const split = path.split('.');
+        let j = split.length;
+        while (j--) {
+          const pathFirstHalf = split.slice(0, j).join('.');
+          const pathLastHalf = split.slice(j).join('.');
+          const _schematype = schema.path(pathFirstHalf);
+          const discriminatorKey = _schematype &&
+            _schematype.schema &&
+            _schematype.schema.options &&
+            _schematype.schema.options.discriminatorKey;
+
+          // gh-6027: if we haven't found the schematype but this path is
+          // underneath an embedded discriminator and the embedded discriminator
+          // key is in the query, use the embedded discriminator schema
+          if (_schematype != null &&
+            (_schematype.schema && _schematype.schema.discriminators) != null &&
+            discriminatorKey != null &&
+            pathLastHalf !== discriminatorKey) {
+            const discriminatorVal = get(obj, pathFirstHalf + '.' + discriminatorKey);
+            if (discriminatorVal != null) {
+              schematype = _schematype.schema.discriminators[discriminatorVal].
+                path(pathLastHalf);
+            }
+          }
+        }
+      }
+
+      if (!schematype) {
+        // Handle potential embedded array queries
+        const split = path.split('.');
+        let j = split.length;
+        let pathFirstHalf;
+        let pathLastHalf;
+        let remainingConds;
+
+        // Find the part of the var path that is a path of the Schema
+        while (j--) {
+          pathFirstHalf = split.slice(0, j).join('.');
+          schematype = schema.path(pathFirstHalf);
+          if (schematype) {
+            break;
+          }
+        }
+
+        // If a substring of the input path resolves to an actual real path...
+        if (schematype) {
+          // Apply the casting; similar code for $elemMatch in schema/array.js
+          if (schematype.caster && schematype.caster.schema) {
+            remainingConds = {};
+            pathLastHalf = split.slice(j).join('.');
+            remainingConds[pathLastHalf] = val;
+
+            const ret = cast(schematype.caster.schema, remainingConds, options, context)[pathLastHalf];
+            if (ret === void 0) {
+              delete obj[path];
+            } else {
+              obj[path] = ret;
+            }
+          } else {
+            obj[path] = val;
+          }
+          continue;
+        }
+
+        if (isObject(val)) {
+          // handle geo schemas that use object notation
+          // { loc: { long: Number, lat: Number }
+
+          let geo = '';
+          if (val.$near) {
+            geo = '$near';
+          } else if (val.$nearSphere) {
+            geo = '$nearSphere';
+          } else if (val.$within) {
+            geo = '$within';
+          } else if (val.$geoIntersects) {
+            geo = '$geoIntersects';
+          } else if (val.$geoWithin) {
+            geo = '$geoWithin';
+          }
+
+          if (geo) {
+            const numbertype = new Types.Number('__QueryCasting__');
+            let value = val[geo];
+
+            if (val.$maxDistance != null) {
+              val.$maxDistance = numbertype.castForQuery(
+                null,
+                val.$maxDistance,
+                context
+              );
+            }
+            if (val.$minDistance != null) {
+              val.$minDistance = numbertype.castForQuery(
+                null,
+                val.$minDistance,
+                context
+              );
+            }
+
+            if (geo === '$within') {
+              const withinType = value.$center
+                  || value.$centerSphere
+                  || value.$box
+                  || value.$polygon;
+
+              if (!withinType) {
+                throw new Error('Bad $within parameter: ' + JSON.stringify(val));
+              }
+
+              value = withinType;
+            } else if (geo === '$near' &&
+                typeof value.type === 'string' && Array.isArray(value.coordinates)) {
+              // geojson; cast the coordinates
+              value = value.coordinates;
+            } else if ((geo === '$near' || geo === '$nearSphere' || geo === '$geoIntersects') &&
+                value.$geometry && typeof value.$geometry.type === 'string' &&
+                Array.isArray(value.$geometry.coordinates)) {
+              if (value.$maxDistance != null) {
+                value.$maxDistance = numbertype.castForQuery(
+                  null,
+                  value.$maxDistance,
+                  context
+                );
+              }
+              if (value.$minDistance != null) {
+                value.$minDistance = numbertype.castForQuery(
+                  null,
+                  value.$minDistance,
+                  context
+                );
+              }
+              if (isMongooseObject(value.$geometry)) {
+                value.$geometry = value.$geometry.toObject({
+                  transform: false,
+                  virtuals: false
+                });
+              }
+              value = value.$geometry.coordinates;
+            } else if (geo === '$geoWithin') {
+              if (value.$geometry) {
+                if (isMongooseObject(value.$geometry)) {
+                  value.$geometry = value.$geometry.toObject({ virtuals: false });
+                }
+                const geoWithinType = value.$geometry.type;
+                if (ALLOWED_GEOWITHIN_GEOJSON_TYPES.indexOf(geoWithinType) === -1) {
+                  throw new Error('Invalid geoJSON type for $geoWithin "' +
+                    geoWithinType + '", must be "Polygon" or "MultiPolygon"');
+                }
+                value = value.$geometry.coordinates;
+              } else {
+                value = value.$box || value.$polygon || value.$center ||
+                  value.$centerSphere;
+                if (isMongooseObject(value)) {
+                  value = value.toObject({ virtuals: false });
+                }
+              }
+            }
+
+            _cast(value, numbertype, context);
+            continue;
+          }
+        }
+
+        if (schema.nested[path]) {
+          continue;
+        }
+
+        const strict = 'strict' in options ? options.strict : schema.options.strict;
+        const strictQuery = getStrictQuery(options, schema._userProvidedOptions, schema.options, context);
+        if (options.upsert && strict) {
+          if (strict === 'throw') {
+            throw new StrictModeError(path);
+          }
+          throw new StrictModeError(path, 'Path "' + path + '" is not in ' +
+            'schema, strict mode is `true`, and upsert is `true`.');
+        } if (strictQuery === 'throw') {
+          throw new StrictModeError(path, 'Path "' + path + '" is not in ' +
+            'schema and strictQuery is \'throw\'.');
+        } else if (strictQuery) {
+          delete obj[path];
+        }
+      } else if (val == null) {
+        continue;
+      } else if (getConstructorName(val) === 'Object') {
+        any$conditionals = Object.keys(val).some(isOperator);
+
+        if (!any$conditionals) {
+          obj[path] = schematype.castForQuery(
+            null,
+            val,
+            context
+          );
+        } else {
+          const ks = Object.keys(val);
+          let $cond;
+
+          let k = ks.length;
+
+          while (k--) {
+            $cond = ks[k];
+            nested = val[$cond];
+
+            if ($cond === '$not') {
+              if (nested && schematype) {
+                _keys = Object.keys(nested);
+                if (_keys.length && isOperator(_keys[0])) {
+                  for (const key in nested) {
+                    nested[key] = schematype.castForQuery(
+                      key,
+                      nested[key],
+                      context
+                    );
+                  }
+                } else {
+                  val[$cond] = schematype.castForQuery(
+                    $cond,
+                    nested,
+                    context
+                  );
+                }
+                continue;
+              }
+            } else {
+              val[$cond] = schematype.castForQuery(
+                $cond,
+                nested,
+                context
+              );
+            }
+          }
+        }
+      } else if (Array.isArray(val) && ['Buffer', 'Array'].indexOf(schematype.instance) === -1) {
+        const casted = [];
+        const valuesArray = val;
+
+        for (const _val of valuesArray) {
+          casted.push(schematype.castForQuery(
+            null,
+            _val,
+            context
+          ));
+        }
+
+        obj[path] = { $in: casted };
+      } else {
+        obj[path] = schematype.castForQuery(
+          null,
+          val,
+          context
+        );
+      }
+    }
+  }
+
+  return obj;
+};
+
+function _cast(val, numbertype, context) {
+  if (Array.isArray(val)) {
+    val.forEach(function(item, i) {
+      if (Array.isArray(item) || isObject(item)) {
+        return _cast(item, numbertype, context);
+      }
+      val[i] = numbertype.castForQuery(null, item, context);
+    });
+  } else {
+    const nearKeys = Object.keys(val);
+    let nearLen = nearKeys.length;
+    while (nearLen--) {
+      const nkey = nearKeys[nearLen];
+      const item = val[nkey];
+      if (Array.isArray(item) || isObject(item)) {
+        _cast(item, numbertype, context);
+        val[nkey] = item;
+      } else {
+        val[nkey] = numbertype.castForQuery({ val: item, context: context });
+      }
+    }
+  }
+}
+
+function getStrictQuery(queryOptions, schemaUserProvidedOptions, schemaOptions, context) {
+  if ('strictQuery' in queryOptions) {
+    return queryOptions.strictQuery;
+  }
+  if ('strictQuery' in schemaUserProvidedOptions) {
+    return schemaUserProvidedOptions.strictQuery;
+  }
+  const mongooseOptions = context &&
+    context.mongooseCollection &&
+    context.mongooseCollection.conn &&
+    context.mongooseCollection.conn.base &&
+    context.mongooseCollection.conn.base.options;
+  if (mongooseOptions) {
+    if ('strictQuery' in mongooseOptions) {
+      return mongooseOptions.strictQuery;
+    }
+  }
+  return schemaOptions.strictQuery;
+}

node_modules/mongoose/lib/cast/boolean.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const CastError = require('../error/cast');
+
+/**
+ * Given a value, cast it to a boolean, or throw a `CastError` if the value
+ * cannot be casted. `null` and `undefined` are considered valid.
+ *
+ * @param {Any} value
+ * @param {String} [path] optional the path to set on the CastError
+ * @return {Boolean|null|undefined}
+ * @throws {CastError} if `value` is not one of the allowed values
+ * @api private
+ */
+
+module.exports = function castBoolean(value, path) {
+  if (module.exports.convertToTrue.has(value)) {
+    return true;
+  }
+  if (module.exports.convertToFalse.has(value)) {
+    return false;
+  }
+
+  if (value == null) {
+    return value;
+  }
+
+  throw new CastError('boolean', value, path);
+};
+
+module.exports.convertToTrue = new Set([true, 'true', 1, '1', 'yes']);
+module.exports.convertToFalse = new Set([false, 'false', 0, '0', 'no']);

node_modules/mongoose/lib/cast/date.js

@@ -0,0 +1,41 @@
+'use strict';
+
+const assert = require('assert');
+
+module.exports = function castDate(value) {
+  // Support empty string because of empty form values. Originally introduced
+  // in https://github.com/Automattic/mongoose/commit/efc72a1898fc3c33a319d915b8c5463a22938dfe
+  if (value == null || value === '') {
+    return null;
+  }
+
+  if (value instanceof Date) {
+    assert.ok(!isNaN(value.valueOf()));
+
+    return value;
+  }
+
+  let date;
+
+  assert.ok(typeof value !== 'boolean');
+
+  if (value instanceof Number || typeof value === 'number') {
+    date = new Date(value);
+  } else if (typeof value === 'string' && !isNaN(Number(value)) && (Number(value) >= 275761 || Number(value) < -271820)) {
+    // string representation of milliseconds take this path
+    date = new Date(Number(value));
+  } else if (typeof value.valueOf === 'function') {
+    // support for moment.js. This is also the path strings will take because
+    // strings have a `valueOf()`
+    date = new Date(value.valueOf());
+  } else {
+    // fallback
+    date = new Date(value);
+  }
+
+  if (!isNaN(date.valueOf())) {
+    return date;
+  }
+
+  assert.ok(false);
+};

node_modules/mongoose/lib/cast/decimal128.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const Decimal128Type = require('../types/decimal128');
+const assert = require('assert');
+
+module.exports = function castDecimal128(value) {
+  if (value == null) {
+    return value;
+  }
+
+  if (typeof value === 'object' && typeof value.$numberDecimal === 'string') {
+    return Decimal128Type.fromString(value.$numberDecimal);
+  }
+
+  if (value instanceof Decimal128Type) {
+    return value;
+  }
+
+  if (typeof value === 'string') {
+    return Decimal128Type.fromString(value);
+  }
+
+  if (typeof Buffer === 'function' && Buffer.isBuffer(value)) {
+    return new Decimal128Type(value);
+  }
+  if (typeof Uint8Array === 'function' && value instanceof Uint8Array) {
+    return new Decimal128Type(value);
+  }
+
+  if (typeof value === 'number') {
+    return Decimal128Type.fromString(String(value));
+  }
+
+  if (typeof value.valueOf === 'function' && typeof value.valueOf() === 'string') {
+    return Decimal128Type.fromString(value.valueOf());
+  }
+
+  assert.ok(false);
+};

node_modules/mongoose/lib/cast/number.js

@@ -0,0 +1,42 @@
+'use strict';
+
+const assert = require('assert');
+
+/**
+ * Given a value, cast it to a number, or throw an `Error` if the value
+ * cannot be casted. `null` and `undefined` are considered valid.
+ *
+ * @param {Any} value
+ * @return {Number}
+ * @throws {Error} if `value` is not one of the allowed values
+ * @api private
+ */
+
+module.exports = function castNumber(val) {
+  if (val == null) {
+    return val;
+  }
+  if (val === '') {
+    return null;
+  }
+
+  if (typeof val === 'string' || typeof val === 'boolean') {
+    val = Number(val);
+  }
+
+  assert.ok(!isNaN(val));
+  if (val instanceof Number) {
+    return val.valueOf();
+  }
+  if (typeof val === 'number') {
+    return val;
+  }
+  if (!Array.isArray(val) && typeof val.valueOf === 'function') {
+    return Number(val.valueOf());
+  }
+  if (val.toString && !Array.isArray(val) && val.toString() == Number(val)) {
+    return Number(val);
+  }
+
+  assert.ok(false);
+};

node_modules/mongoose/lib/cast/objectid.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const isBsonType = require('../helpers/isBsonType');
+const ObjectId = require('../types/objectid');
+
+module.exports = function castObjectId(value) {
+  if (value == null) {
+    return value;
+  }
+
+  if (isBsonType(value, 'ObjectId')) {
+    return value;
+  }
+
+  if (value._id) {
+    if (isBsonType(value._id, 'ObjectId')) {
+      return value._id;
+    }
+    if (value._id.toString instanceof Function) {
+      return new ObjectId(value._id.toString());
+    }
+  }
+
+  if (value.toString instanceof Function) {
+    return new ObjectId(value.toString());
+  }
+
+  return new ObjectId(value);
+};

node_modules/mongoose/lib/cast/string.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const CastError = require('../error/cast');
+
+/**
+ * Given a value, cast it to a string, or throw a `CastError` if the value
+ * cannot be casted. `null` and `undefined` are considered valid.
+ *
+ * @param {Any} value
+ * @param {String} [path] optional the path to set on the CastError
+ * @return {string|null|undefined}
+ * @throws {CastError}
+ * @api private
+ */
+
+module.exports = function castString(value, path) {
+  // If null or undefined
+  if (value == null) {
+    return value;
+  }
+
+  // handle documents being passed
+  if (value._id && typeof value._id === 'string') {
+    return value._id;
+  }
+
+  // Re: gh-647 and gh-3030, we're ok with casting using `toString()`
+  // **unless** its the default Object.toString, because "[object Object]"
+  // doesn't really qualify as useful data
+  if (value.toString &&
+      value.toString !== Object.prototype.toString &&
+      !Array.isArray(value)) {
+    return value.toString();
+  }
+
+  throw new CastError('string', value, path);
+};

node_modules/mongoose/lib/collection.js

@@ -0,0 +1,327 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const EventEmitter = require('events').EventEmitter;
+const STATES = require('./connectionstate');
+const immediate = require('./helpers/immediate');
+
+/**
+ * Abstract Collection constructor
+ *
+ * This is the base class that drivers inherit from and implement.
+ *
+ * @param {String} name name of the collection
+ * @param {Connection} conn A MongooseConnection instance
+ * @param {Object} [opts] optional collection options
+ * @api public
+ */
+
+function Collection(name, conn, opts) {
+  if (opts === void 0) {
+    opts = {};
+  }
+
+  this.opts = opts;
+  this.name = name;
+  this.collectionName = name;
+  this.conn = conn;
+  this.queue = [];
+  this.buffer = true;
+  this.emitter = new EventEmitter();
+
+  if (STATES.connected === this.conn.readyState) {
+    this.onOpen();
+  }
+}
+
+/**
+ * The collection name
+ *
+ * @api public
+ * @property name
+ */
+
+Collection.prototype.name;
+
+/**
+ * The collection name
+ *
+ * @api public
+ * @property collectionName
+ */
+
+Collection.prototype.collectionName;
+
+/**
+ * The Connection instance
+ *
+ * @api public
+ * @property conn
+ */
+
+Collection.prototype.conn;
+
+/**
+ * Called when the database connects
+ *
+ * @api private
+ */
+
+Collection.prototype.onOpen = function() {
+  this.buffer = false;
+  immediate(() => this.doQueue());
+};
+
+/**
+ * Called when the database disconnects
+ *
+ * @api private
+ */
+
+Collection.prototype.onClose = function() {};
+
+/**
+ * Queues a method for later execution when its
+ * database connection opens.
+ *
+ * @param {String} name name of the method to queue
+ * @param {Array} args arguments to pass to the method when executed
+ * @api private
+ */
+
+Collection.prototype.addQueue = function(name, args) {
+  this.queue.push([name, args]);
+  return this;
+};
+
+/**
+ * Removes a queued method
+ *
+ * @param {String} name name of the method to queue
+ * @param {Array} args arguments to pass to the method when executed
+ * @api private
+ */
+
+Collection.prototype.removeQueue = function(name, args) {
+  const index = this.queue.findIndex(v => v[0] === name && v[1] === args);
+  if (index === -1) {
+    return false;
+  }
+  this.queue.splice(index, 1);
+  return true;
+};
+
+/**
+ * Executes all queued methods and clears the queue.
+ *
+ * @api private
+ */
+
+Collection.prototype.doQueue = function() {
+  for (const method of this.queue) {
+    if (typeof method[0] === 'function') {
+      method[0].apply(this, method[1]);
+    } else {
+      this[method[0]].apply(this, method[1]);
+    }
+  }
+  this.queue = [];
+  const _this = this;
+  immediate(function() {
+    _this.emitter.emit('queue');
+  });
+  return this;
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.ensureIndex = function() {
+  throw new Error('Collection#ensureIndex unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.createIndex = function() {
+  throw new Error('Collection#createIndex unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.findAndModify = function() {
+  throw new Error('Collection#findAndModify unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.findOneAndUpdate = function() {
+  throw new Error('Collection#findOneAndUpdate unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.findOneAndDelete = function() {
+  throw new Error('Collection#findOneAndDelete unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.findOneAndReplace = function() {
+  throw new Error('Collection#findOneAndReplace unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.findOne = function() {
+  throw new Error('Collection#findOne unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.find = function() {
+  throw new Error('Collection#find unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.insert = function() {
+  throw new Error('Collection#insert unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.insertOne = function() {
+  throw new Error('Collection#insertOne unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.insertMany = function() {
+  throw new Error('Collection#insertMany unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.save = function() {
+  throw new Error('Collection#save unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.updateOne = function() {
+  throw new Error('Collection#updateOne unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.updateMany = function() {
+  throw new Error('Collection#updateMany unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.deleteOne = function() {
+  throw new Error('Collection#deleteOne unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.deleteMany = function() {
+  throw new Error('Collection#deleteMany unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.getIndexes = function() {
+  throw new Error('Collection#getIndexes unimplemented by driver');
+};
+
+/**
+ * Abstract method that drivers must implement.
+ */
+
+Collection.prototype.watch = function() {
+  throw new Error('Collection#watch unimplemented by driver');
+};
+
+/*!
+ * ignore
+ */
+
+Collection.prototype._shouldBufferCommands = function _shouldBufferCommands() {
+  const opts = this.opts;
+
+  if (opts.bufferCommands != null) {
+    return opts.bufferCommands;
+  }
+  if (opts && opts.schemaUserProvidedOptions != null && opts.schemaUserProvidedOptions.bufferCommands != null) {
+    return opts.schemaUserProvidedOptions.bufferCommands;
+  }
+
+  return this.conn._shouldBufferCommands();
+};
+
+/*!
+ * ignore
+ */
+
+Collection.prototype._getBufferTimeoutMS = function _getBufferTimeoutMS() {
+  const conn = this.conn;
+  const opts = this.opts;
+
+  if (opts.bufferTimeoutMS != null) {
+    return opts.bufferTimeoutMS;
+  }
+  if (opts && opts.schemaUserProvidedOptions != null && opts.schemaUserProvidedOptions.bufferTimeoutMS != null) {
+    return opts.schemaUserProvidedOptions.bufferTimeoutMS;
+  }
+  if (conn.config.bufferTimeoutMS != null) {
+    return conn.config.bufferTimeoutMS;
+  }
+  if (conn.base != null && conn.base.get('bufferTimeoutMS') != null) {
+    return conn.base.get('bufferTimeoutMS');
+  }
+  return 10000;
+};
+
+/*!
+ * Module exports.
+ */
+
+module.exports = Collection;

node_modules/mongoose/lib/connectionstate.js

@@ -0,0 +1,26 @@
+
+/*!
+ * Connection states
+ */
+
+'use strict';
+
+const STATES = module.exports = exports = Object.create(null);
+
+const disconnected = 'disconnected';
+const connected = 'connected';
+const connecting = 'connecting';
+const disconnecting = 'disconnecting';
+const uninitialized = 'uninitialized';
+
+STATES[0] = disconnected;
+STATES[1] = connected;
+STATES[2] = connecting;
+STATES[3] = disconnecting;
+STATES[99] = uninitialized;
+
+STATES[disconnected] = 0;
+STATES[connected] = 1;
+STATES[connecting] = 2;
+STATES[disconnecting] = 3;
+STATES[uninitialized] = 99;

node_modules/mongoose/lib/cursor/AggregationCursor.js

@@ -0,0 +1,386 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('../error/mongooseError');
+const Readable = require('stream').Readable;
+const eachAsync = require('../helpers/cursor/eachAsync');
+const immediate = require('../helpers/immediate');
+const util = require('util');
+
+/**
+ * An AggregationCursor is a concurrency primitive for processing aggregation
+ * results one document at a time. It is analogous to QueryCursor.
+ *
+ * An AggregationCursor fulfills the Node.js streams3 API,
+ * in addition to several other mechanisms for loading documents from MongoDB
+ * one at a time.
+ *
+ * Creating an AggregationCursor executes the model's pre aggregate hooks,
+ * but **not** the model's post aggregate hooks.
+ *
+ * Unless you're an advanced user, do **not** instantiate this class directly.
+ * Use [`Aggregate#cursor()`](/docs/api/aggregate.html#aggregate_Aggregate-cursor) instead.
+ *
+ * @param {Aggregate} agg
+ * @inherits Readable https://nodejs.org/api/stream.html#class-streamreadable
+ * @event `cursor`: Emitted when the cursor is created
+ * @event `error`: Emitted when an error occurred
+ * @event `data`: Emitted when the stream is flowing and the next doc is ready
+ * @event `end`: Emitted when the stream is exhausted
+ * @api public
+ */
+
+function AggregationCursor(agg) {
+  // set autoDestroy=true because on node 12 it's by default false
+  // gh-10902 need autoDestroy to destroy correctly and emit 'close' event
+  Readable.call(this, { autoDestroy: true, objectMode: true });
+
+  this.cursor = null;
+  this.agg = agg;
+  this._transforms = [];
+  const model = agg._model;
+  delete agg.options.cursor.useMongooseAggCursor;
+  this._mongooseOptions = {};
+
+  _init(model, this, agg);
+}
+
+util.inherits(AggregationCursor, Readable);
+
+/*!
+ * ignore
+ */
+
+function _init(model, c, agg) {
+  if (!model.collection.buffer) {
+    model.hooks.execPre('aggregate', agg, function() {
+      c.cursor = model.collection.aggregate(agg._pipeline, agg.options || {});
+      c.emit('cursor', c.cursor);
+    });
+  } else {
+    model.collection.emitter.once('queue', function() {
+      model.hooks.execPre('aggregate', agg, function() {
+        c.cursor = model.collection.aggregate(agg._pipeline, agg.options || {});
+        c.emit('cursor', c.cursor);
+      });
+    });
+  }
+}
+
+/**
+ * Necessary to satisfy the Readable API
+ * @method _read
+ * @memberOf AggregationCursor
+ * @instance
+ * @api private
+ */
+
+AggregationCursor.prototype._read = function() {
+  const _this = this;
+  _next(this, function(error, doc) {
+    if (error) {
+      return _this.emit('error', error);
+    }
+    if (!doc) {
+      _this.push(null);
+      _this.cursor.close(function(error) {
+        if (error) {
+          return _this.emit('error', error);
+        }
+      });
+      return;
+    }
+    _this.push(doc);
+  });
+};
+
+if (Symbol.asyncIterator != null) {
+  const msg = 'Mongoose does not support using async iterators with an ' +
+    'existing aggregation cursor. See https://bit.ly/mongoose-async-iterate-aggregation';
+
+  AggregationCursor.prototype[Symbol.asyncIterator] = function() {
+    throw new MongooseError(msg);
+  };
+}
+
+/**
+ * Registers a transform function which subsequently maps documents retrieved
+ * via the streams interface or `.next()`
+ *
+ * #### Example:
+ *
+ *     // Map documents returned by `data` events
+ *     Thing.
+ *       find({ name: /^hello/ }).
+ *       cursor().
+ *       map(function (doc) {
+ *        doc.foo = "bar";
+ *        return doc;
+ *       })
+ *       on('data', function(doc) { console.log(doc.foo); });
+ *
+ *     // Or map documents returned by `.next()`
+ *     const cursor = Thing.find({ name: /^hello/ }).
+ *       cursor().
+ *       map(function (doc) {
+ *         doc.foo = "bar";
+ *         return doc;
+ *       });
+ *     cursor.next(function(error, doc) {
+ *       console.log(doc.foo);
+ *     });
+ *
+ * @param {Function} fn
+ * @return {AggregationCursor}
+ * @memberOf AggregationCursor
+ * @api public
+ * @method map
+ */
+
+Object.defineProperty(AggregationCursor.prototype, 'map', {
+  value: function(fn) {
+    this._transforms.push(fn);
+    return this;
+  },
+  enumerable: true,
+  configurable: true,
+  writable: true
+});
+
+/**
+ * Marks this cursor as errored
+ * @method _markError
+ * @instance
+ * @memberOf AggregationCursor
+ * @api private
+ */
+
+AggregationCursor.prototype._markError = function(error) {
+  this._error = error;
+  return this;
+};
+
+/**
+ * Marks this cursor as closed. Will stop streaming and subsequent calls to
+ * `next()` will error.
+ *
+ * @param {Function} callback
+ * @return {Promise}
+ * @api public
+ * @method close
+ * @emits close
+ * @see AggregationCursor.close https://mongodb.github.io/node-mongodb-native/4.9/classes/AggregationCursor.html#close
+ */
+
+AggregationCursor.prototype.close = async function close() {
+  if (typeof arguments[0] === 'function') {
+    throw new MongooseError('AggregationCursor.prototype.close() no longer accepts a callback');
+  }
+  try {
+    await this.cursor.close();
+  } catch (error) {
+    this.listeners('error').length > 0 && this.emit('error', error);
+    throw error;
+  }
+  this.emit('close');
+};
+
+/**
+ * Get the next document from this cursor. Will return `null` when there are
+ * no documents left.
+ *
+ * @return {Promise}
+ * @api public
+ * @method next
+ */
+
+AggregationCursor.prototype.next = async function next() {
+  if (typeof arguments[0] === 'function') {
+    throw new MongooseError('AggregationCursor.prototype.next() no longer accepts a callback');
+  }
+  return new Promise((resolve, reject) => {
+    _next(this, (err, res) => {
+      if (err != null) {
+        return reject(err);
+      }
+      resolve(res);
+    });
+  });
+};
+
+/**
+ * Execute `fn` for every document in the cursor. If `fn` returns a promise,
+ * will wait for the promise to resolve before iterating on to the next one.
+ * Returns a promise that resolves when done.
+ *
+ * @param {Function} fn
+ * @param {Object} [options]
+ * @param {Number} [options.parallel] the number of promises to execute in parallel. Defaults to 1.
+ * @param {Function} [callback] executed when all docs have been processed
+ * @return {Promise}
+ * @api public
+ * @method eachAsync
+ */
+
+AggregationCursor.prototype.eachAsync = function(fn, opts, callback) {
+  const _this = this;
+  if (typeof opts === 'function') {
+    callback = opts;
+    opts = {};
+  }
+  opts = opts || {};
+
+  return eachAsync(function(cb) { return _next(_this, cb); }, fn, opts, callback);
+};
+
+/**
+ * Returns an asyncIterator for use with [`for/await/of` loops](https://thecodebarbarian.com/getting-started-with-async-iterators-in-node-js)
+ * You do not need to call this function explicitly, the JavaScript runtime
+ * will call it for you.
+ *
+ * #### Example:
+ *
+ *     // Async iterator without explicitly calling `cursor()`. Mongoose still
+ *     // creates an AggregationCursor instance internally.
+ *     const agg = Model.aggregate([{ $match: { age: { $gte: 25 } } }]);
+ *     for await (const doc of agg) {
+ *       console.log(doc.name);
+ *     }
+ *
+ *     // You can also use an AggregationCursor instance for async iteration
+ *     const cursor = Model.aggregate([{ $match: { age: { $gte: 25 } } }]).cursor();
+ *     for await (const doc of cursor) {
+ *       console.log(doc.name);
+ *     }
+ *
+ * Node.js 10.x supports async iterators natively without any flags. You can
+ * enable async iterators in Node.js 8.x using the [`--harmony_async_iteration` flag](https://github.com/tc39/proposal-async-iteration/issues/117#issuecomment-346695187).
+ *
+ * **Note:** This function is not set if `Symbol.asyncIterator` is undefined. If
+ * `Symbol.asyncIterator` is undefined, that means your Node.js version does not
+ * support async iterators.
+ *
+ * @method [Symbol.asyncIterator]
+ * @memberOf AggregationCursor
+ * @instance
+ * @api public
+ */
+
+if (Symbol.asyncIterator != null) {
+  AggregationCursor.prototype[Symbol.asyncIterator] = function() {
+    return this.transformNull()._transformForAsyncIterator();
+  };
+}
+
+/*!
+ * ignore
+ */
+
+AggregationCursor.prototype._transformForAsyncIterator = function() {
+  if (this._transforms.indexOf(_transformForAsyncIterator) === -1) {
+    this.map(_transformForAsyncIterator);
+  }
+  return this;
+};
+
+/*!
+ * ignore
+ */
+
+AggregationCursor.prototype.transformNull = function(val) {
+  if (arguments.length === 0) {
+    val = true;
+  }
+  this._mongooseOptions.transformNull = val;
+  return this;
+};
+
+/*!
+ * ignore
+ */
+
+function _transformForAsyncIterator(doc) {
+  return doc == null ? { done: true } : { value: doc, done: false };
+}
+
+/**
+ * Adds a [cursor flag](https://mongodb.github.io/node-mongodb-native/4.9/classes/AggregationCursor.html#addCursorFlag).
+ * Useful for setting the `noCursorTimeout` and `tailable` flags.
+ *
+ * @param {String} flag
+ * @param {Boolean} value
+ * @return {AggregationCursor} this
+ * @api public
+ * @method addCursorFlag
+ */
+
+AggregationCursor.prototype.addCursorFlag = function(flag, value) {
+  const _this = this;
+  _waitForCursor(this, function() {
+    _this.cursor.addCursorFlag(flag, value);
+  });
+  return this;
+};
+
+/*!
+ * ignore
+ */
+
+function _waitForCursor(ctx, cb) {
+  if (ctx.cursor) {
+    return cb();
+  }
+  ctx.once('cursor', function() {
+    cb();
+  });
+}
+
+/**
+ * Get the next doc from the underlying cursor and mongooseify it
+ * (populate, etc.)
+ * @param {Any} ctx
+ * @param {Function} cb
+ * @api private
+ */
+
+function _next(ctx, cb) {
+  let callback = cb;
+  if (ctx._transforms.length) {
+    callback = function(err, doc) {
+      if (err || (doc === null && !ctx._mongooseOptions.transformNull)) {
+        return cb(err, doc);
+      }
+      cb(err, ctx._transforms.reduce(function(doc, fn) {
+        return fn(doc);
+      }, doc));
+    };
+  }
+
+  if (ctx._error) {
+    return immediate(function() {
+      callback(ctx._error);
+    });
+  }
+
+  if (ctx.cursor) {
+    return ctx.cursor.next().then(
+      doc => {
+        if (!doc) {
+          return callback(null, null);
+        }
+
+        callback(null, doc);
+      },
+      err => callback(err)
+    );
+  } else {
+    ctx.once('cursor', function() {
+      _next(ctx, cb);
+    });
+  }
+}
+
+module.exports = AggregationCursor;

node_modules/mongoose/lib/cursor/ChangeStream.js

@@ -0,0 +1,151 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const EventEmitter = require('events').EventEmitter;
+
+/*!
+ * ignore
+ */
+
+class ChangeStream extends EventEmitter {
+  constructor(changeStreamThunk, pipeline, options) {
+    super();
+
+    this.driverChangeStream = null;
+    this.closed = false;
+    this.bindedEvents = false;
+    this.pipeline = pipeline;
+    this.options = options;
+
+    if (options && options.hydrate && !options.model) {
+      throw new Error(
+        'Cannot create change stream with `hydrate: true` ' +
+        'unless calling `Model.watch()`'
+      );
+    }
+
+    // This wrapper is necessary because of buffering.
+    changeStreamThunk((err, driverChangeStream) => {
+      if (err != null) {
+        this.emit('error', err);
+        return;
+      }
+
+      this.driverChangeStream = driverChangeStream;
+      this.emit('ready');
+    });
+  }
+
+  _bindEvents() {
+    if (this.bindedEvents) {
+      return;
+    }
+
+    this.bindedEvents = true;
+
+    if (this.driverChangeStream == null) {
+      this.once('ready', () => {
+        this.driverChangeStream.on('close', () => {
+          this.closed = true;
+        });
+
+        ['close', 'change', 'end', 'error'].forEach(ev => {
+          this.driverChangeStream.on(ev, data => {
+            // Sometimes Node driver still polls after close, so
+            // avoid any uncaught exceptions due to closed change streams
+            // See tests for gh-7022
+            if (ev === 'error' && this.closed) {
+              return;
+            }
+            if (data != null && data.fullDocument != null && this.options && this.options.hydrate) {
+              data.fullDocument = this.options.model.hydrate(data.fullDocument);
+            }
+            this.emit(ev, data);
+          });
+        });
+      });
+
+      return;
+    }
+
+    this.driverChangeStream.on('close', () => {
+      this.closed = true;
+    });
+
+    ['close', 'change', 'end', 'error'].forEach(ev => {
+      this.driverChangeStream.on(ev, data => {
+        // Sometimes Node driver still polls after close, so
+        // avoid any uncaught exceptions due to closed change streams
+        // See tests for gh-7022
+        if (ev === 'error' && this.closed) {
+          return;
+        }
+        this.emit(ev, data);
+      });
+    });
+  }
+
+  hasNext(cb) {
+    return this.driverChangeStream.hasNext(cb);
+  }
+
+  next(cb) {
+    if (this.options && this.options.hydrate) {
+      if (cb != null) {
+        const originalCb = cb;
+        cb = (err, data) => {
+          if (err != null) {
+            return originalCb(err);
+          }
+          if (data.fullDocument != null) {
+            data.fullDocument = this.options.model.hydrate(data.fullDocument);
+          }
+          return originalCb(null, data);
+        };
+      }
+
+      let maybePromise = this.driverChangeStream.next(cb);
+      if (maybePromise && typeof maybePromise.then === 'function') {
+        maybePromise = maybePromise.then(data => {
+          if (data.fullDocument != null) {
+            data.fullDocument = this.options.model.hydrate(data.fullDocument);
+          }
+          return data;
+        });
+      }
+      return maybePromise;
+    }
+
+    return this.driverChangeStream.next(cb);
+  }
+
+  on(event, handler) {
+    this._bindEvents();
+    return super.on(event, handler);
+  }
+
+  once(event, handler) {
+    this._bindEvents();
+    return super.once(event, handler);
+  }
+
+  _queue(cb) {
+    this.once('ready', () => cb());
+  }
+
+  close() {
+    this.closed = true;
+    if (this.driverChangeStream) {
+      this.driverChangeStream.close();
+    }
+  }
+}
+
+/*!
+ * ignore
+ */
+
+module.exports = ChangeStream;

node_modules/mongoose/lib/cursor/QueryCursor.js

@@ -0,0 +1,554 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('../error/mongooseError');
+const Readable = require('stream').Readable;
+const eachAsync = require('../helpers/cursor/eachAsync');
+const helpers = require('../queryhelpers');
+const immediate = require('../helpers/immediate');
+const util = require('util');
+
+/**
+ * A QueryCursor is a concurrency primitive for processing query results
+ * one document at a time. A QueryCursor fulfills the Node.js streams3 API,
+ * in addition to several other mechanisms for loading documents from MongoDB
+ * one at a time.
+ *
+ * QueryCursors execute the model's pre `find` hooks before loading any documents
+ * from MongoDB, and the model's post `find` hooks after loading each document.
+ *
+ * Unless you're an advanced user, do **not** instantiate this class directly.
+ * Use [`Query#cursor()`](/docs/api/query.html#query_Query-cursor) instead.
+ *
+ * @param {Query} query
+ * @param {Object} options query options passed to `.find()`
+ * @inherits Readable https://nodejs.org/api/stream.html#class-streamreadable
+ * @event `cursor`: Emitted when the cursor is created
+ * @event `error`: Emitted when an error occurred
+ * @event `data`: Emitted when the stream is flowing and the next doc is ready
+ * @event `end`: Emitted when the stream is exhausted
+ * @api public
+ */
+
+function QueryCursor(query, options) {
+  // set autoDestroy=true because on node 12 it's by default false
+  // gh-10902 need autoDestroy to destroy correctly and emit 'close' event
+  Readable.call(this, { autoDestroy: true, objectMode: true });
+
+  this.cursor = null;
+  this.query = query;
+  const _this = this;
+  const model = query.model;
+  this._mongooseOptions = {};
+  this._transforms = [];
+  this.model = model;
+  this.options = options || {};
+
+  model.hooks.execPre('find', query, (err) => {
+    if (err != null) {
+      _this._markError(err);
+      _this.listeners('error').length > 0 && _this.emit('error', err);
+      return;
+    }
+    this._transforms = this._transforms.concat(query._transforms.slice());
+    if (this.options.transform) {
+      this._transforms.push(options.transform);
+    }
+    // Re: gh-8039, you need to set the `cursor.batchSize` option, top-level
+    // `batchSize` option doesn't work.
+    if (this.options.batchSize) {
+      this.options.cursor = options.cursor || {};
+      this.options.cursor.batchSize = options.batchSize;
+
+      // Max out the number of documents we'll populate in parallel at 5000.
+      this.options._populateBatchSize = Math.min(this.options.batchSize, 5000);
+    }
+    model.collection.find(query._conditions, this.options, (err, cursor) => {
+      if (err != null) {
+        _this._markError(err);
+        _this.listeners('error').length > 0 && _this.emit('error', _this._error);
+        return;
+      }
+
+      if (_this._error) {
+        cursor.close(function() {});
+        _this.listeners('error').length > 0 && _this.emit('error', _this._error);
+      }
+      _this.cursor = cursor;
+      _this.emit('cursor', cursor);
+    });
+  });
+}
+
+util.inherits(QueryCursor, Readable);
+
+/**
+ * Necessary to satisfy the Readable API
+ * @method _read
+ * @memberOf QueryCursor
+ * @instance
+ * @api private
+ */
+
+QueryCursor.prototype._read = function() {
+  const _this = this;
+  _next(this, function(error, doc) {
+    if (error) {
+      return _this.emit('error', error);
+    }
+    if (!doc) {
+      _this.push(null);
+      _this.cursor.close(function(error) {
+        if (error) {
+          return _this.emit('error', error);
+        }
+      });
+      return;
+    }
+    _this.push(doc);
+  });
+};
+
+/**
+ * Registers a transform function which subsequently maps documents retrieved
+ * via the streams interface or `.next()`
+ *
+ * #### Example:
+ *
+ *     // Map documents returned by `data` events
+ *     Thing.
+ *       find({ name: /^hello/ }).
+ *       cursor().
+ *       map(function (doc) {
+ *        doc.foo = "bar";
+ *        return doc;
+ *       })
+ *       on('data', function(doc) { console.log(doc.foo); });
+ *
+ *     // Or map documents returned by `.next()`
+ *     const cursor = Thing.find({ name: /^hello/ }).
+ *       cursor().
+ *       map(function (doc) {
+ *         doc.foo = "bar";
+ *         return doc;
+ *       });
+ *     cursor.next(function(error, doc) {
+ *       console.log(doc.foo);
+ *     });
+ *
+ * @param {Function} fn
+ * @return {QueryCursor}
+ * @memberOf QueryCursor
+ * @api public
+ * @method map
+ */
+
+Object.defineProperty(QueryCursor.prototype, 'map', {
+  value: function(fn) {
+    this._transforms.push(fn);
+    return this;
+  },
+  enumerable: true,
+  configurable: true,
+  writable: true
+});
+
+/**
+ * Marks this cursor as errored
+ * @method _markError
+ * @memberOf QueryCursor
+ * @instance
+ * @api private
+ */
+
+QueryCursor.prototype._markError = function(error) {
+  this._error = error;
+  return this;
+};
+
+/**
+ * Marks this cursor as closed. Will stop streaming and subsequent calls to
+ * `next()` will error.
+ *
+ * @return {Promise}
+ * @api public
+ * @method close
+ * @emits close
+ * @see AggregationCursor.close https://mongodb.github.io/node-mongodb-native/4.9/classes/AggregationCursor.html#close
+ */
+
+QueryCursor.prototype.close = async function close() {
+  if (typeof arguments[0] === 'function') {
+    throw new MongooseError('QueryCursor.prototype.close() no longer accepts a callback');
+  }
+  try {
+    await this.cursor.close();
+    this.emit('close');
+  } catch (error) {
+    this.listeners('error').length > 0 && this.emit('error', error);
+    throw error;
+  }
+};
+
+/**
+ * Rewind this cursor to its uninitialized state. Any options that are present on the cursor will
+ * remain in effect. Iterating this cursor will cause new queries to be sent to the server, even
+ * if the resultant data has already been retrieved by this cursor.
+ *
+ * @return {AggregationCursor} this
+ * @api public
+ * @method rewind
+ */
+
+QueryCursor.prototype.rewind = function() {
+  const _this = this;
+  _waitForCursor(this, function() {
+    _this.cursor.rewind();
+  });
+  return this;
+};
+
+/**
+ * Get the next document from this cursor. Will return `null` when there are
+ * no documents left.
+ *
+ * @return {Promise}
+ * @api public
+ * @method next
+ */
+
+QueryCursor.prototype.next = async function next() {
+  if (arguments[0] === 'function') {
+    throw new MongooseError('QueryCursor.prototype.next() no longer accepts a callback');
+  }
+  return new Promise((resolve, reject) => {
+    _next(this, function(error, doc) {
+      if (error) {
+        return reject(error);
+      }
+      resolve(doc);
+    });
+  });
+};
+
+/**
+ * Execute `fn` for every document in the cursor. If `fn` returns a promise,
+ * will wait for the promise to resolve before iterating on to the next one.
+ * Returns a promise that resolves when done.
+ *
+ * #### Example:
+ *
+ *     // Iterate over documents asynchronously
+ *     Thing.
+ *       find({ name: /^hello/ }).
+ *       cursor().
+ *       eachAsync(async function (doc, i) {
+ *         doc.foo = doc.bar + i;
+ *         await doc.save();
+ *       })
+ *
+ * @param {Function} fn
+ * @param {Object} [options]
+ * @param {Number} [options.parallel] the number of promises to execute in parallel. Defaults to 1.
+ * @param {Number} [options.batchSize] if set, will call `fn()` with arrays of documents with length at most `batchSize`
+ * @param {Boolean} [options.continueOnError=false] if true, `eachAsync()` iterates through all docs even if `fn` throws an error. If false, `eachAsync()` throws an error immediately if the given function `fn()` throws an error.
+ * @param {Function} [callback] executed when all docs have been processed
+ * @return {Promise}
+ * @api public
+ * @method eachAsync
+ */
+
+QueryCursor.prototype.eachAsync = function(fn, opts, callback) {
+  const _this = this;
+  if (typeof opts === 'function') {
+    callback = opts;
+    opts = {};
+  }
+  opts = opts || {};
+
+  return eachAsync(function(cb) { return _next(_this, cb); }, fn, opts, callback);
+};
+
+/**
+ * The `options` passed in to the `QueryCursor` constructor.
+ *
+ * @api public
+ * @property options
+ */
+
+QueryCursor.prototype.options;
+
+/**
+ * Adds a [cursor flag](https://mongodb.github.io/node-mongodb-native/4.9/classes/FindCursor.html#addCursorFlag).
+ * Useful for setting the `noCursorTimeout` and `tailable` flags.
+ *
+ * @param {String} flag
+ * @param {Boolean} value
+ * @return {AggregationCursor} this
+ * @api public
+ * @method addCursorFlag
+ */
+
+QueryCursor.prototype.addCursorFlag = function(flag, value) {
+  const _this = this;
+  _waitForCursor(this, function() {
+    _this.cursor.addCursorFlag(flag, value);
+  });
+  return this;
+};
+
+/*!
+ * ignore
+ */
+
+QueryCursor.prototype.transformNull = function(val) {
+  if (arguments.length === 0) {
+    val = true;
+  }
+  this._mongooseOptions.transformNull = val;
+  return this;
+};
+
+/*!
+ * ignore
+ */
+
+QueryCursor.prototype._transformForAsyncIterator = function() {
+  if (this._transforms.indexOf(_transformForAsyncIterator) === -1) {
+    this.map(_transformForAsyncIterator);
+  }
+  return this;
+};
+
+/**
+ * Returns an asyncIterator for use with [`for/await/of` loops](https://thecodebarbarian.com/getting-started-with-async-iterators-in-node-js).
+ * You do not need to call this function explicitly, the JavaScript runtime
+ * will call it for you.
+ *
+ * #### Example:
+ *
+ *     // Works without using `cursor()`
+ *     for await (const doc of Model.find([{ $sort: { name: 1 } }])) {
+ *       console.log(doc.name);
+ *     }
+ *
+ *     // Can also use `cursor()`
+ *     for await (const doc of Model.find([{ $sort: { name: 1 } }]).cursor()) {
+ *       console.log(doc.name);
+ *     }
+ *
+ * Node.js 10.x supports async iterators natively without any flags. You can
+ * enable async iterators in Node.js 8.x using the [`--harmony_async_iteration` flag](https://github.com/tc39/proposal-async-iteration/issues/117#issuecomment-346695187).
+ *
+ * **Note:** This function is not if `Symbol.asyncIterator` is undefined. If
+ * `Symbol.asyncIterator` is undefined, that means your Node.js version does not
+ * support async iterators.
+ *
+ * @method [Symbol.asyncIterator]
+ * @memberOf QueryCursor
+ * @instance
+ * @api public
+ */
+
+if (Symbol.asyncIterator != null) {
+  QueryCursor.prototype[Symbol.asyncIterator] = function() {
+    return this.transformNull()._transformForAsyncIterator();
+  };
+}
+
+/*!
+ * ignore
+ */
+
+function _transformForAsyncIterator(doc) {
+  return doc == null ? { done: true } : { value: doc, done: false };
+}
+
+/**
+ * Get the next doc from the underlying cursor and mongooseify it
+ * (populate, etc.)
+ * @param {Any} ctx
+ * @param {Function} cb
+ * @api private
+ */
+
+function _next(ctx, cb) {
+  let callback = cb;
+  if (ctx._transforms.length) {
+    callback = function(err, doc) {
+      if (err || (doc === null && !ctx._mongooseOptions.transformNull)) {
+        return cb(err, doc);
+      }
+      cb(err, ctx._transforms.reduce(function(doc, fn) {
+        return fn.call(ctx, doc);
+      }, doc));
+    };
+  }
+
+  if (ctx._error) {
+    return immediate(function() {
+      callback(ctx._error);
+    });
+  }
+
+  if (ctx.cursor) {
+    if (ctx.query._mongooseOptions.populate && !ctx._pop) {
+      ctx._pop = helpers.preparePopulationOptionsMQ(ctx.query,
+        ctx.query._mongooseOptions);
+      ctx._pop.__noPromise = true;
+    }
+    if (ctx.query._mongooseOptions.populate && ctx.options._populateBatchSize > 1) {
+      if (ctx._batchDocs && ctx._batchDocs.length) {
+        // Return a cached populated doc
+        return _nextDoc(ctx, ctx._batchDocs.shift(), ctx._pop, callback);
+      } else if (ctx._batchExhausted) {
+        // Internal cursor reported no more docs. Act the same here
+        return callback(null, null);
+      } else {
+        // Request as many docs as batchSize, to populate them also in batch
+        ctx._batchDocs = [];
+        ctx.cursor.next().then(
+          res => { _onNext.call({ ctx, callback }, null, res); },
+          err => { _onNext.call({ ctx, callback }, err); }
+        );
+        return;
+      }
+    } else {
+      return ctx.cursor.next().then(
+        doc => {
+          if (!doc) {
+            callback(null, null);
+            return;
+          }
+
+          if (!ctx.query._mongooseOptions.populate) {
+            return _nextDoc(ctx, doc, null, callback);
+          }
+
+          ctx.query.model.populate(doc, ctx._pop).then(
+            doc => {
+              _nextDoc(ctx, doc, ctx._pop, callback);
+            },
+            err => {
+              callback(err);
+            }
+          );
+        },
+        error => {
+          callback(error);
+        }
+      );
+    }
+  } else {
+    ctx.once('error', cb);
+
+    ctx.once('cursor', function(cursor) {
+      ctx.removeListener('error', cb);
+      if (cursor == null) {
+        return;
+      }
+      _next(ctx, cb);
+    });
+  }
+}
+
+/*!
+ * ignore
+ */
+
+function _onNext(error, doc) {
+  if (error) {
+    return this.callback(error);
+  }
+  if (!doc) {
+    this.ctx._batchExhausted = true;
+    return _populateBatch.call(this);
+  }
+
+  this.ctx._batchDocs.push(doc);
+
+  if (this.ctx._batchDocs.length < this.ctx.options._populateBatchSize) {
+    // If both `batchSize` and `_populateBatchSize` are huge, calling `next()` repeatedly may
+    // cause a stack overflow. So make sure we clear the stack regularly.
+    if (this.ctx._batchDocs.length > 0 && this.ctx._batchDocs.length % 1000 === 0) {
+      return immediate(() => this.ctx.cursor.next().then(
+        res => { _onNext.call(this, null, res); },
+        err => { _onNext.call(this, err); }
+      ));
+    }
+    this.ctx.cursor.next().then(
+      res => { _onNext.call(this, null, res); },
+      err => { _onNext.call(this, err); }
+    );
+  } else {
+    _populateBatch.call(this);
+  }
+}
+
+/*!
+ * ignore
+ */
+
+function _populateBatch() {
+  if (!this.ctx._batchDocs.length) {
+    return this.callback(null, null);
+  }
+  const _this = this;
+  this.ctx.query.model.populate(this.ctx._batchDocs, this.ctx._pop).then(
+    () => {
+      _nextDoc(_this.ctx, _this.ctx._batchDocs.shift(), _this.ctx._pop, _this.callback);
+    },
+    err => {
+      _this.callback(err);
+    }
+  );
+}
+
+/*!
+ * ignore
+ */
+
+function _nextDoc(ctx, doc, pop, callback) {
+  if (ctx.query._mongooseOptions.lean) {
+    return ctx.model.hooks.execPost('find', ctx.query, [[doc]], err => {
+      if (err != null) {
+        return callback(err);
+      }
+      callback(null, doc);
+    });
+  }
+
+  const { model, _fields, _userProvidedFields, options } = ctx.query;
+  helpers.createModelAndInit(model, doc, _fields, _userProvidedFields, options, pop, (err, doc) => {
+    if (err != null) {
+      return callback(err);
+    }
+    ctx.model.hooks.execPost('find', ctx.query, [[doc]], err => {
+      if (err != null) {
+        return callback(err);
+      }
+      callback(null, doc);
+    });
+  });
+}
+
+/*!
+ * ignore
+ */
+
+function _waitForCursor(ctx, cb) {
+  if (ctx.cursor) {
+    return cb();
+  }
+  ctx.once('cursor', function(cursor) {
+    if (cursor == null) {
+      return;
+    }
+    cb();
+  });
+}
+
+module.exports = QueryCursor;

node_modules/mongoose/lib/document_provider.js

@@ -0,0 +1,30 @@
+'use strict';
+
+/* eslint-env browser */
+
+/*!
+ * Module dependencies.
+ */
+const Document = require('./document.js');
+const BrowserDocument = require('./browserDocument.js');
+
+let isBrowser = false;
+
+/**
+ * Returns the Document constructor for the current context
+ *
+ * @api private
+ */
+module.exports = function() {
+  if (isBrowser) {
+    return BrowserDocument;
+  }
+  return Document;
+};
+
+/*!
+ * ignore
+ */
+module.exports.setBrowser = function(flag) {
+  isBrowser = flag;
+};

node_modules/mongoose/lib/driver.js

@@ -0,0 +1,15 @@
+'use strict';
+
+/*!
+ * ignore
+ */
+
+let driver = null;
+
+module.exports.get = function() {
+  return driver;
+};
+
+module.exports.set = function(v) {
+  driver = v;
+};

node_modules/mongoose/lib/drivers/SPEC.md

@@ -0,0 +1,4 @@
+
+# Driver Spec
+
+TODO

node_modules/mongoose/lib/drivers/browser/binary.js

@@ -0,0 +1,14 @@
+
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const Binary = require('bson').Binary;
+
+/*!
+ * Module exports.
+ */
+
+module.exports = exports = Binary;

node_modules/mongoose/lib/drivers/browser/decimal128.js

@@ -0,0 +1,7 @@
+/*!
+ * ignore
+ */
+
+'use strict';
+
+module.exports = require('bson').Decimal128;

node_modules/mongoose/lib/drivers/browser/index.js

@@ -0,0 +1,12 @@
+/*!
+ * Module exports.
+ */
+
+'use strict';
+
+exports.Collection = function() {
+  throw new Error('Cannot create a collection from browser library');
+};
+exports.Connection = function() {
+  throw new Error('Cannot create a connection from browser library');
+};

node_modules/mongoose/lib/drivers/browser/objectid.js

@@ -0,0 +1,29 @@
+
+/*!
+ * [node-mongodb-native](https://github.com/mongodb/node-mongodb-native) ObjectId
+ * @constructor NodeMongoDbObjectId
+ * @see ObjectId
+ */
+
+'use strict';
+
+const ObjectId = require('bson').ObjectID;
+
+/**
+ * Getter for convenience with populate, see gh-6115
+ * @api private
+ */
+
+Object.defineProperty(ObjectId.prototype, '_id', {
+  enumerable: false,
+  configurable: true,
+  get: function() {
+    return this;
+  }
+});
+
+/*!
+ * ignore
+ */
+
+module.exports = exports = ObjectId;

node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js

@@ -0,0 +1,455 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseCollection = require('../../collection');
+const MongooseError = require('../../error/mongooseError');
+const Collection = require('mongodb').Collection;
+const ObjectId = require('../../types/objectid');
+const getConstructorName = require('../../helpers/getConstructorName');
+const stream = require('stream');
+const util = require('util');
+
+/**
+ * A [node-mongodb-native](https://github.com/mongodb/node-mongodb-native) collection implementation.
+ *
+ * All methods methods from the [node-mongodb-native](https://github.com/mongodb/node-mongodb-native) driver are copied and wrapped in queue management.
+ *
+ * @inherits Collection https://mongodb.github.io/node-mongodb-native/4.9/classes/Collection.html
+ * @api private
+ */
+
+function NativeCollection(name, conn, options) {
+  this.collection = null;
+  this.Promise = options.Promise || Promise;
+  this.modelName = options.modelName;
+  delete options.modelName;
+  this._closed = false;
+  MongooseCollection.apply(this, arguments);
+}
+
+/*!
+ * Inherit from abstract Collection.
+ */
+
+Object.setPrototypeOf(NativeCollection.prototype, MongooseCollection.prototype);
+
+/**
+ * Called when the connection opens.
+ *
+ * @api private
+ */
+
+NativeCollection.prototype.onOpen = function() {
+  this.collection = this.conn.db.collection(this.name);
+  MongooseCollection.prototype.onOpen.call(this);
+  return this.collection;
+};
+
+/**
+ * Called when the connection closes
+ *
+ * @api private
+ */
+
+NativeCollection.prototype.onClose = function(force) {
+  MongooseCollection.prototype.onClose.call(this, force);
+};
+
+/**
+ * Helper to get the collection, in case `this.collection` isn't set yet.
+ * May happen if `bufferCommands` is false and created the model when
+ * Mongoose was disconnected.
+ *
+ * @api private
+ */
+
+NativeCollection.prototype._getCollection = function _getCollection() {
+  if (this.collection) {
+    return this.collection;
+  }
+  if (this.conn.db != null) {
+    this.collection = this.conn.db.collection(this.name);
+    return this.collection;
+  }
+  return null;
+};
+
+/*!
+ * ignore
+ */
+
+const syncCollectionMethods = { watch: true, find: true, aggregate: true };
+
+/**
+ * Copy the collection methods and make them subject to queues
+ * @param {Number|String} I
+ * @api private
+ */
+
+function iter(i) {
+  NativeCollection.prototype[i] = function() {
+    const collection = this._getCollection();
+    const args = Array.from(arguments);
+    const _this = this;
+    const globalDebug = _this &&
+      _this.conn &&
+      _this.conn.base &&
+      _this.conn.base.options &&
+      _this.conn.base.options.debug;
+    const connectionDebug = _this &&
+      _this.conn &&
+      _this.conn.options &&
+      _this.conn.options.debug;
+    const debug = connectionDebug == null ? globalDebug : connectionDebug;
+    const lastArg = arguments[arguments.length - 1];
+    const opId = new ObjectId();
+
+    // If user force closed, queueing will hang forever. See #5664
+    if (this.conn.$wasForceClosed) {
+      const error = new MongooseError('Connection was force closed');
+      if (args.length > 0 &&
+        typeof args[args.length - 1] === 'function') {
+        args[args.length - 1](error);
+        return;
+      } else {
+        throw error;
+      }
+    }
+
+    let _args = args;
+    let callback = null;
+    if (this._shouldBufferCommands() && this.buffer) {
+      this.conn.emit('buffer', {
+        _id: opId,
+        modelName: _this.modelName,
+        collectionName: _this.name,
+        method: i,
+        args: args
+      });
+
+      let callback;
+      let _args = args;
+      let promise = null;
+      let timeout = null;
+      if (syncCollectionMethods[i] && typeof lastArg === 'function') {
+        this.addQueue(() => {
+          lastArg.call(this, null, this[i].apply(this, _args.slice(0, _args.length - 1)));
+        }, []);
+      } else if (syncCollectionMethods[i]) {
+        promise = new Promise((resolve, reject) => {
+          callback = function collectionOperationCallback(err, res) {
+            if (timeout != null) {
+              clearTimeout(timeout);
+            }
+            if (err != null) {
+              return reject(err);
+            }
+            resolve(res);
+          };
+          _args = args.concat([callback]);
+          this.addQueue(i, _args);
+        });
+      } else if (typeof lastArg === 'function') {
+        callback = function collectionOperationCallback() {
+          if (timeout != null) {
+            clearTimeout(timeout);
+          }
+          return lastArg.apply(this, arguments);
+        };
+        _args = args.slice(0, args.length - 1).concat([callback]);
+      } else {
+        promise = new Promise((resolve, reject) => {
+          callback = function collectionOperationCallback(err, res) {
+            if (timeout != null) {
+              clearTimeout(timeout);
+            }
+            if (err != null) {
+              return reject(err);
+            }
+            resolve(res);
+          };
+          _args = args.concat([callback]);
+          this.addQueue(i, _args);
+        });
+      }
+
+      const bufferTimeoutMS = this._getBufferTimeoutMS();
+      timeout = setTimeout(() => {
+        const removed = this.removeQueue(i, _args);
+        if (removed) {
+          const message = 'Operation `' + this.name + '.' + i + '()` buffering timed out after ' +
+            bufferTimeoutMS + 'ms';
+          const err = new MongooseError(message);
+          this.conn.emit('buffer-end', { _id: opId, modelName: _this.modelName, collectionName: _this.name, method: i, error: err });
+          callback(err);
+        }
+      }, bufferTimeoutMS);
+
+      if (!syncCollectionMethods[i] && typeof lastArg === 'function') {
+        this.addQueue(i, _args);
+        return;
+      }
+
+      return promise;
+    } else if (!syncCollectionMethods[i] && typeof lastArg === 'function') {
+      callback = function collectionOperationCallback(err, res) {
+        if (err != null) {
+          _this.conn.emit('operation-end', { _id: opId, modelName: _this.modelName, collectionName: _this.name, method: i, error: err });
+        } else {
+          _this.conn.emit('operation-end', { _id: opId, modelName: _this.modelName, collectionName: _this.name, method: i, result: res });
+        }
+        return lastArg.apply(this, arguments);
+      };
+      _args = args.slice(0, args.length - 1).concat([callback]);
+    }
+
+    if (debug) {
+      if (typeof debug === 'function') {
+        debug.apply(_this,
+          [_this.name, i].concat(args.slice(0, args.length - 1)));
+      } else if (debug instanceof stream.Writable) {
+        this.$printToStream(_this.name, i, args, debug);
+      } else {
+        const color = debug.color == null ? true : debug.color;
+        const shell = debug.shell == null ? false : debug.shell;
+        this.$print(_this.name, i, args, color, shell);
+      }
+    }
+
+    this.conn.emit('operation-start', { _id: opId, modelName: _this.modelName, collectionName: this.name, method: i, params: _args });
+
+    try {
+      if (collection == null) {
+        const message = 'Cannot call `' + this.name + '.' + i + '()` before initial connection ' +
+          'is complete if `bufferCommands = false`. Make sure you `await mongoose.connect()` if ' +
+          'you have `bufferCommands = false`.';
+        throw new MongooseError(message);
+      }
+
+      if (syncCollectionMethods[i] && typeof lastArg === 'function') {
+        const ret = collection[i].apply(collection, _args.slice(0, _args.length - 1));
+        return lastArg.call(this, null, ret);
+      }
+
+      const ret = collection[i].apply(collection, _args);
+      if (ret != null && typeof ret.then === 'function') {
+        return ret.then(
+          res => {
+            typeof lastArg === 'function' && lastArg(null, res);
+            return res;
+          },
+          err => {
+            if (typeof lastArg === 'function') {
+              lastArg(err);
+              return;
+            }
+            throw err;
+          }
+        );
+      }
+      return ret;
+    } catch (error) {
+      // Collection operation may throw because of max bson size, catch it here
+      // See gh-3906
+      if (typeof lastArg === 'function') {
+        return lastArg(error);
+      } else {
+        this.conn.emit('operation-end', { _id: opId, modelName: _this.modelName, collectionName: this.name, method: i, error: error });
+
+        throw error;
+      }
+    }
+  };
+}
+
+for (const key of Object.getOwnPropertyNames(Collection.prototype)) {
+  // Janky hack to work around gh-3005 until we can get rid of the mongoose
+  // collection abstraction
+  const descriptor = Object.getOwnPropertyDescriptor(Collection.prototype, key);
+  // Skip properties with getters because they may throw errors (gh-8528)
+  if (descriptor.get !== undefined) {
+    continue;
+  }
+  if (typeof Collection.prototype[key] !== 'function') {
+    continue;
+  }
+
+  iter(key);
+}
+
+/**
+ * Debug print helper
+ *
+ * @api public
+ * @method $print
+ */
+
+NativeCollection.prototype.$print = function(name, i, args, color, shell) {
+  const moduleName = color ? '\x1B[0;36mMongoose:\x1B[0m ' : 'Mongoose: ';
+  const functionCall = [name, i].join('.');
+  const _args = [];
+  for (let j = args.length - 1; j >= 0; --j) {
+    if (this.$format(args[j]) || _args.length) {
+      _args.unshift(this.$format(args[j], color, shell));
+    }
+  }
+  const params = '(' + _args.join(', ') + ')';
+
+  console.info(moduleName + functionCall + params);
+};
+
+/**
+ * Debug print helper
+ *
+ * @api public
+ * @method $print
+ */
+
+NativeCollection.prototype.$printToStream = function(name, i, args, stream) {
+  const functionCall = [name, i].join('.');
+  const _args = [];
+  for (let j = args.length - 1; j >= 0; --j) {
+    if (this.$format(args[j]) || _args.length) {
+      _args.unshift(this.$format(args[j]));
+    }
+  }
+  const params = '(' + _args.join(', ') + ')';
+
+  stream.write(functionCall + params, 'utf8');
+};
+
+/**
+ * Formatter for debug print args
+ *
+ * @api public
+ * @method $format
+ */
+
+NativeCollection.prototype.$format = function(arg, color, shell) {
+  const type = typeof arg;
+  if (type === 'function' || type === 'undefined') return '';
+  return format(arg, false, color, shell);
+};
+
+/**
+ * Debug print helper
+ * @param {Any} representation
+ * @api private
+ */
+
+function inspectable(representation) {
+  const ret = {
+    inspect: function() { return representation; }
+  };
+  if (util.inspect.custom) {
+    ret[util.inspect.custom] = ret.inspect;
+  }
+  return ret;
+}
+function map(o) {
+  return format(o, true);
+}
+function formatObjectId(x, key) {
+  x[key] = inspectable('ObjectId("' + x[key].toHexString() + '")');
+}
+function formatDate(x, key, shell) {
+  if (shell) {
+    x[key] = inspectable('ISODate("' + x[key].toUTCString() + '")');
+  } else {
+    x[key] = inspectable('new Date("' + x[key].toUTCString() + '")');
+  }
+}
+function format(obj, sub, color, shell) {
+  if (obj && typeof obj.toBSON === 'function') {
+    obj = obj.toBSON();
+  }
+  if (obj == null) {
+    return obj;
+  }
+
+  const clone = require('../../helpers/clone');
+  let x = clone(obj, { transform: false });
+  const constructorName = getConstructorName(x);
+
+  if (constructorName === 'Binary') {
+    x = 'BinData(' + x.sub_type + ', "' + x.toString('base64') + '")';
+  } else if (constructorName === 'ObjectId') {
+    x = inspectable('ObjectId("' + x.toHexString() + '")');
+  } else if (constructorName === 'Date') {
+    x = inspectable('new Date("' + x.toUTCString() + '")');
+  } else if (constructorName === 'Object') {
+    const keys = Object.keys(x);
+    const numKeys = keys.length;
+    let key;
+    for (let i = 0; i < numKeys; ++i) {
+      key = keys[i];
+      if (x[key]) {
+        let error;
+        if (typeof x[key].toBSON === 'function') {
+          try {
+            // `session.toBSON()` throws an error. This means we throw errors
+            // in debug mode when using transactions, see gh-6712. As a
+            // workaround, catch `toBSON()` errors, try to serialize without
+            // `toBSON()`, and rethrow if serialization still fails.
+            x[key] = x[key].toBSON();
+          } catch (_error) {
+            error = _error;
+          }
+        }
+        const _constructorName = getConstructorName(x[key]);
+        if (_constructorName === 'Binary') {
+          x[key] = 'BinData(' + x[key].sub_type + ', "' +
+            x[key].buffer.toString('base64') + '")';
+        } else if (_constructorName === 'Object') {
+          x[key] = format(x[key], true);
+        } else if (_constructorName === 'ObjectId') {
+          formatObjectId(x, key);
+        } else if (_constructorName === 'Date') {
+          formatDate(x, key, shell);
+        } else if (_constructorName === 'ClientSession') {
+          x[key] = inspectable('ClientSession("' +
+            (
+              x[key] &&
+              x[key].id &&
+              x[key].id.id &&
+              x[key].id.id.buffer || ''
+            ).toString('hex') + '")');
+        } else if (Array.isArray(x[key])) {
+          x[key] = x[key].map(map);
+        } else if (error != null) {
+          // If there was an error with `toBSON()` and the object wasn't
+          // already converted to a string representation, rethrow it.
+          // Open to better ideas on how to handle this.
+          throw error;
+        }
+      }
+    }
+  }
+  if (sub) {
+    return x;
+  }
+
+  return util.
+    inspect(x, false, 10, color).
+    replace(/\n/g, '').
+    replace(/\s{2,}/g, ' ');
+}
+
+/**
+ * Retrieves information about this collections indexes.
+ *
+ * @param {Function} callback
+ * @method getIndexes
+ * @api public
+ */
+
+NativeCollection.prototype.getIndexes = NativeCollection.prototype.indexInformation;
+
+/*!
+ * Module exports.
+ */
+
+module.exports = NativeCollection;

node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js

@@ -0,0 +1,162 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseConnection = require('../../connection');
+const STATES = require('../../connectionstate');
+const setTimeout = require('../../helpers/timers').setTimeout;
+
+/**
+ * A [node-mongodb-native](https://github.com/mongodb/node-mongodb-native) connection implementation.
+ *
+ * @inherits Connection
+ * @api private
+ */
+
+function NativeConnection() {
+  MongooseConnection.apply(this, arguments);
+  this._listening = false;
+}
+
+/**
+ * Expose the possible connection states.
+ * @api public
+ */
+
+NativeConnection.STATES = STATES;
+
+/*!
+ * Inherits from Connection.
+ */
+
+Object.setPrototypeOf(NativeConnection.prototype, MongooseConnection.prototype);
+
+/**
+ * Switches to a different database using the same connection pool.
+ *
+ * Returns a new connection object, with the new db. If you set the `useCache`
+ * option, `useDb()` will cache connections by `name`.
+ *
+ * **Note:** Calling `close()` on a `useDb()` connection will close the base connection as well.
+ *
+ * @param {String} name The database name
+ * @param {Object} [options]
+ * @param {Boolean} [options.useCache=false] If true, cache results so calling `useDb()` multiple times with the same name only creates 1 connection object.
+ * @param {Boolean} [options.noListener=false] If true, the new connection object won't listen to any events on the base connection. This is better for memory usage in cases where you're calling `useDb()` for every request.
+ * @return {Connection} New Connection Object
+ * @api public
+ */
+
+NativeConnection.prototype.useDb = function(name, options) {
+  // Return immediately if cached
+  options = options || {};
+  if (options.useCache && this.relatedDbs[name]) {
+    return this.relatedDbs[name];
+  }
+
+  // we have to manually copy all of the attributes...
+  const newConn = new this.constructor();
+  newConn.name = name;
+  newConn.base = this.base;
+  newConn.collections = {};
+  newConn.models = {};
+  newConn.replica = this.replica;
+  newConn.config = Object.assign({}, this.config, newConn.config);
+  newConn.name = this.name;
+  newConn.options = this.options;
+  newConn._readyState = this._readyState;
+  newConn._closeCalled = this._closeCalled;
+  newConn._hasOpened = this._hasOpened;
+  newConn._listening = false;
+  newConn._parent = this;
+
+  newConn.host = this.host;
+  newConn.port = this.port;
+  newConn.user = this.user;
+  newConn.pass = this.pass;
+
+  // First, when we create another db object, we are not guaranteed to have a
+  // db object to work with. So, in the case where we have a db object and it
+  // is connected, we can just proceed with setting everything up. However, if
+  // we do not have a db or the state is not connected, then we need to wait on
+  // the 'open' event of the connection before doing the rest of the setup
+  // the 'connected' event is the first time we'll have access to the db object
+
+  const _this = this;
+
+  newConn.client = _this.client;
+
+  if (this.db && this._readyState === STATES.connected) {
+    wireup();
+  } else {
+    this.once('connected', wireup);
+  }
+
+  function wireup() {
+    newConn.client = _this.client;
+    const _opts = {};
+    if (options.hasOwnProperty('noListener')) {
+      _opts.noListener = options.noListener;
+    }
+    newConn.db = _this.client.db(name, _opts);
+    newConn.onOpen();
+  }
+
+  newConn.name = name;
+
+  // push onto the otherDbs stack, this is used when state changes
+  if (options.noListener !== true) {
+    this.otherDbs.push(newConn);
+  }
+  newConn.otherDbs.push(this);
+
+  // push onto the relatedDbs cache, this is used when state changes
+  if (options && options.useCache) {
+    this.relatedDbs[newConn.name] = newConn;
+    newConn.relatedDbs = this.relatedDbs;
+  }
+
+  return newConn;
+};
+
+/**
+ * Closes the connection
+ *
+ * @param {Boolean} [force]
+ * @return {Connection} this
+ * @api private
+ */
+
+NativeConnection.prototype.doClose = async function doClose(force) {
+  if (this.client == null) {
+    return this;
+  }
+
+  let skipCloseClient = false;
+  if (force != null && typeof force === 'object') {
+    skipCloseClient = force.skipCloseClient;
+    force = force.force;
+  }
+
+  if (skipCloseClient) {
+    return this;
+  }
+
+  await this.client.close(force);
+  // Defer because the driver will wait at least 1ms before finishing closing
+  // the pool, see https://github.com/mongodb-js/mongodb-core/blob/a8f8e4ce41936babc3b9112bf42d609779f03b39/lib/connection/pool.js#L1026-L1030.
+  // If there's queued operations, you may still get some background work
+  // after the callback is called.
+  await new Promise(resolve => setTimeout(resolve, 1));
+
+  return this;
+};
+
+
+/*!
+ * Module exports.
+ */
+
+module.exports = NativeConnection;

node_modules/mongoose/lib/drivers/node-mongodb-native/index.js

@@ -0,0 +1,8 @@
+/*!
+ * Module exports.
+ */
+
+'use strict';
+
+exports.Collection = require('./collection');
+exports.Connection = require('./connection');

node_modules/mongoose/lib/error/browserMissingSchema.js

@@ -0,0 +1,28 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+class MissingSchemaError extends MongooseError {
+  /**
+   * MissingSchema Error constructor.
+   */
+  constructor() {
+    super('Schema hasn\'t been registered for document.\n'
+      + 'Use mongoose.Document(name, schema)');
+  }
+}
+
+Object.defineProperty(MissingSchemaError.prototype, 'name', {
+  value: 'MongooseError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = MissingSchemaError;

node_modules/mongoose/lib/error/cast.js

@@ -0,0 +1,158 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./mongooseError');
+const util = require('util');
+
+/**
+ * Casting Error constructor.
+ *
+ * @param {String} type
+ * @param {String} value
+ * @inherits MongooseError
+ * @api private
+ */
+
+class CastError extends MongooseError {
+  constructor(type, value, path, reason, schemaType) {
+    // If no args, assume we'll `init()` later.
+    if (arguments.length > 0) {
+      const stringValue = getStringValue(value);
+      const valueType = getValueType(value);
+      const messageFormat = getMessageFormat(schemaType);
+      const msg = formatMessage(null, type, stringValue, path, messageFormat, valueType, reason);
+      super(msg);
+      this.init(type, value, path, reason, schemaType);
+    } else {
+      super(formatMessage());
+    }
+  }
+
+  toJSON() {
+    return {
+      stringValue: this.stringValue,
+      valueType: this.valueType,
+      kind: this.kind,
+      value: this.value,
+      path: this.path,
+      reason: this.reason,
+      name: this.name,
+      message: this.message
+    };
+  }
+  /*!
+   * ignore
+   */
+  init(type, value, path, reason, schemaType) {
+    this.stringValue = getStringValue(value);
+    this.messageFormat = getMessageFormat(schemaType);
+    this.kind = type;
+    this.value = value;
+    this.path = path;
+    this.reason = reason;
+    this.valueType = getValueType(value);
+  }
+
+  /**
+   * ignore
+   * @param {Readonly<CastError>} other
+   * @api private
+   */
+  copy(other) {
+    this.messageFormat = other.messageFormat;
+    this.stringValue = other.stringValue;
+    this.kind = other.kind;
+    this.value = other.value;
+    this.path = other.path;
+    this.reason = other.reason;
+    this.message = other.message;
+    this.valueType = other.valueType;
+  }
+
+  /*!
+   * ignore
+   */
+  setModel(model) {
+    this.model = model;
+    this.message = formatMessage(model, this.kind, this.stringValue, this.path,
+      this.messageFormat, this.valueType);
+  }
+}
+
+Object.defineProperty(CastError.prototype, 'name', {
+  value: 'CastError'
+});
+
+function getStringValue(value) {
+  let stringValue = util.inspect(value);
+  stringValue = stringValue.replace(/^'|'$/g, '"');
+  if (!stringValue.startsWith('"')) {
+    stringValue = '"' + stringValue + '"';
+  }
+  return stringValue;
+}
+
+function getValueType(value) {
+  if (value == null) {
+    return '' + value;
+  }
+
+  const t = typeof value;
+  if (t !== 'object') {
+    return t;
+  }
+  if (typeof value.constructor !== 'function') {
+    return t;
+  }
+  return value.constructor.name;
+}
+
+function getMessageFormat(schemaType) {
+  const messageFormat = schemaType &&
+  schemaType.options &&
+  schemaType.options.cast || null;
+  if (typeof messageFormat === 'string') {
+    return messageFormat;
+  }
+}
+
+/*!
+ * ignore
+ */
+
+function formatMessage(model, kind, stringValue, path, messageFormat, valueType, reason) {
+  if (messageFormat != null) {
+    let ret = messageFormat.
+      replace('{KIND}', kind).
+      replace('{VALUE}', stringValue).
+      replace('{PATH}', path);
+    if (model != null) {
+      ret = ret.replace('{MODEL}', model.modelName);
+    }
+
+    return ret;
+  } else {
+    const valueTypeMsg = valueType ? ' (type ' + valueType + ')' : '';
+    let ret = 'Cast to ' + kind + ' failed for value ' +
+      stringValue + valueTypeMsg + ' at path "' + path + '"';
+    if (model != null) {
+      ret += ' for model "' + model.modelName + '"';
+    }
+    if (reason != null &&
+        typeof reason.constructor === 'function' &&
+        reason.constructor.name !== 'AssertionError' &&
+        reason.constructor.name !== 'Error') {
+      ret += ' because of "' + reason.constructor.name + '"';
+    }
+    return ret;
+  }
+}
+
+/*!
+ * exports
+ */
+
+module.exports = CastError;

node_modules/mongoose/lib/error/divergentArray.js

@@ -0,0 +1,38 @@
+
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+class DivergentArrayError extends MongooseError {
+  /**
+   * DivergentArrayError constructor.
+   * @param {Array<String>} paths
+   * @api private
+   */
+  constructor(paths) {
+    const msg = 'For your own good, using `document.save()` to update an array '
+            + 'which was selected using an $elemMatch projection OR '
+            + 'populated using skip, limit, query conditions, or exclusion of '
+            + 'the _id field when the operation results in a $pop or $set of '
+            + 'the entire array is not supported. The following '
+            + 'path(s) would have been modified unsafely:\n'
+            + '  ' + paths.join('\n  ') + '\n'
+            + 'Use Model.updateOne() to update these arrays instead.';
+    // TODO write up a docs page (FAQ) and link to it
+    super(msg);
+  }
+}
+
+Object.defineProperty(DivergentArrayError.prototype, 'name', {
+  value: 'DivergentArrayError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = DivergentArrayError;

node_modules/mongoose/lib/error/eachAsyncMultiError.js

@@ -0,0 +1,41 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+/**
+ * If `eachAsync()` is called with `continueOnError: true`, there can be
+ * multiple errors. This error class contains an `errors` property, which
+ * contains an array of all errors that occurred in `eachAsync()`.
+ *
+ * @api private
+ */
+
+class EachAsyncMultiError extends MongooseError {
+  /**
+   * @param {String} connectionString
+   */
+  constructor(errors) {
+    let preview = errors.map(e => e.message).join(', ');
+    if (preview.length > 50) {
+      preview = preview.slice(0, 50) + '...';
+    }
+    super(`eachAsync() finished with ${errors.length} errors: ${preview}`);
+
+    this.errors = errors;
+  }
+}
+
+Object.defineProperty(EachAsyncMultiError.prototype, 'name', {
+  value: 'EachAsyncMultiError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = EachAsyncMultiError;

node_modules/mongoose/lib/error/index.js

@@ -0,0 +1,227 @@
+'use strict';
+
+/**
+ * MongooseError constructor. MongooseError is the base class for all
+ * Mongoose-specific errors.
+ *
+ * #### Example:
+ *
+ *     const Model = mongoose.model('Test', new mongoose.Schema({ answer: Number }));
+ *     const doc = new Model({ answer: 'not a number' });
+ *     const err = doc.validateSync();
+ *
+ *     err instanceof mongoose.Error.ValidationError; // true
+ *
+ * @constructor Error
+ * @param {String} msg Error message
+ * @inherits Error https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error
+ */
+
+const MongooseError = require('./mongooseError');
+
+/**
+ * The name of the error. The name uniquely identifies this Mongoose error. The
+ * possible values are:
+ *
+ * - `MongooseError`: general Mongoose error
+ * - `CastError`: Mongoose could not convert a value to the type defined in the schema path. May be in a `ValidationError` class' `errors` property.
+ * - `DivergentArrayError`: You attempted to `save()` an array that was modified after you loaded it with a `$elemMatch` or similar projection
+ * - `MissingSchemaError`: You tried to access a model with [`mongoose.model()`](mongoose.html#mongoose_Mongoose-model) that was not defined
+ * - `DocumentNotFoundError`: The document you tried to [`save()`](document.html#document_Document-save) was not found
+ * - `ValidatorError`: error from an individual schema path's validator
+ * - `ValidationError`: error returned from [`validate()`](document.html#document_Document-validate) or [`validateSync()`](document.html#document_Document-validateSync). Contains zero or more `ValidatorError` instances in `.errors` property.
+ * - `MissingSchemaError`: You called `mongoose.Document()` without a schema
+ * - `ObjectExpectedError`: Thrown when you set a nested path to a non-object value with [strict mode set](/docs/guide.html#strict).
+ * - `ObjectParameterError`: Thrown when you pass a non-object value to a function which expects an object as a paramter
+ * - `OverwriteModelError`: Thrown when you call [`mongoose.model()`](mongoose.html#mongoose_Mongoose-model) to re-define a model that was already defined.
+ * - `ParallelSaveError`: Thrown when you call [`save()`](model.html#model_Model-save) on a document when the same document instance is already saving.
+ * - `StrictModeError`: Thrown when you set a path that isn't the schema and [strict mode](/docs/guide.html#strict) is set to `throw`.
+ * - `VersionError`: Thrown when the [document is out of sync](/docs/guide.html#versionKey)
+ *
+ * @api public
+ * @property {String} name
+ * @memberOf Error
+ * @instance
+ */
+
+/*!
+ * Module exports.
+ */
+
+module.exports = exports = MongooseError;
+
+/**
+ * The default built-in validator error messages.
+ *
+ * @see Error.messages #error_messages_MongooseError-messages
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.messages = require('./messages');
+
+// backward compat
+MongooseError.Messages = MongooseError.messages;
+
+/**
+ * An instance of this error class will be returned when `save()` fails
+ * because the underlying
+ * document was not found. The constructor takes one parameter, the
+ * conditions that mongoose passed to `updateOne()` when trying to update
+ * the document.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.DocumentNotFoundError = require('./notFound');
+
+/**
+ * An instance of this error class will be returned when mongoose failed to
+ * cast a value.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.CastError = require('./cast');
+
+/**
+ * An instance of this error class will be returned when [validation](/docs/validation.html) failed.
+ * The `errors` property contains an object whose keys are the paths that failed and whose values are
+ * instances of CastError or ValidationError.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.ValidationError = require('./validation');
+
+/**
+ * A `ValidationError` has a hash of `errors` that contain individual
+ * `ValidatorError` instances.
+ *
+ * #### Example:
+ *
+ *     const schema = Schema({ name: { type: String, required: true } });
+ *     const Model = mongoose.model('Test', schema);
+ *     const doc = new Model({});
+ *
+ *     // Top-level error is a ValidationError, **not** a ValidatorError
+ *     const err = doc.validateSync();
+ *     err instanceof mongoose.Error.ValidationError; // true
+ *
+ *     // A ValidationError `err` has 0 or more ValidatorErrors keyed by the
+ *     // path in the `err.errors` property.
+ *     err.errors['name'] instanceof mongoose.Error.ValidatorError;
+ *
+ *     err.errors['name'].kind; // 'required'
+ *     err.errors['name'].path; // 'name'
+ *     err.errors['name'].value; // undefined
+ *
+ * Instances of `ValidatorError` have the following properties:
+ *
+ * - `kind`: The validator's `type`, like `'required'` or `'regexp'`
+ * - `path`: The path that failed validation
+ * - `value`: The value that failed validation
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.ValidatorError = require('./validator');
+
+/**
+ * An instance of this error class will be returned when you call `save()` after
+ * the document in the database was changed in a potentially unsafe way. See
+ * the [`versionKey` option](/docs/guide.html#versionKey) for more information.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.VersionError = require('./version');
+
+/**
+ * An instance of this error class will be returned when you call `save()` multiple
+ * times on the same document in parallel. See the [FAQ](/docs/faq.html) for more
+ * information.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.ParallelSaveError = require('./parallelSave');
+
+/**
+ * Thrown when a model with the given name was already registered on the connection.
+ * See [the FAQ about `OverwriteModelError`](/docs/faq.html#overwrite-model-error).
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.OverwriteModelError = require('./overwriteModel');
+
+/**
+ * Thrown when you try to access a model that has not been registered yet
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.MissingSchemaError = require('./missingSchema');
+
+/**
+ * Thrown when the MongoDB Node driver can't connect to a valid server
+ * to send an operation to.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.MongooseServerSelectionError = require('./serverSelection');
+
+/**
+ * An instance of this error will be returned if you used an array projection
+ * and then modified the array in an unsafe way.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.DivergentArrayError = require('./divergentArray');
+
+/**
+ * Thrown when your try to pass values to model constructor that
+ * were not specified in schema or change immutable properties when
+ * `strict` mode is `"throw"`
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.StrictModeError = require('./strict');
+
+/**
+ * An instance of this error class will be returned when mongoose failed to
+ * populate with a path that is not existing.
+ *
+ * @api public
+ * @memberOf Error
+ * @static
+ */
+
+MongooseError.StrictPopulateError = require('./strictPopulate');

node_modules/mongoose/lib/error/messages.js

@@ -0,0 +1,47 @@
+
+/**
+ * The default built-in validator error messages. These may be customized.
+ *
+ *     // customize within each schema or globally like so
+ *     const mongoose = require('mongoose');
+ *     mongoose.Error.messages.String.enum  = "Your custom message for {PATH}.";
+ *
+ * As you might have noticed, error messages support basic templating
+ *
+ * - `{PATH}` is replaced with the invalid document path
+ * - `{VALUE}` is replaced with the invalid value
+ * - `{TYPE}` is replaced with the validator type such as "regexp", "min", or "user defined"
+ * - `{MIN}` is replaced with the declared min value for the Number.min validator
+ * - `{MAX}` is replaced with the declared max value for the Number.max validator
+ *
+ * Click the "show code" link below to see all defaults.
+ *
+ * @static
+ * @memberOf MongooseError
+ * @api public
+ */
+
+'use strict';
+
+const msg = module.exports = exports = {};
+
+msg.DocumentNotFoundError = null;
+
+msg.general = {};
+msg.general.default = 'Validator failed for path `{PATH}` with value `{VALUE}`';
+msg.general.required = 'Path `{PATH}` is required.';
+
+msg.Number = {};
+msg.Number.min = 'Path `{PATH}` ({VALUE}) is less than minimum allowed value ({MIN}).';
+msg.Number.max = 'Path `{PATH}` ({VALUE}) is more than maximum allowed value ({MAX}).';
+msg.Number.enum = '`{VALUE}` is not a valid enum value for path `{PATH}`.';
+
+msg.Date = {};
+msg.Date.min = 'Path `{PATH}` ({VALUE}) is before minimum allowed value ({MIN}).';
+msg.Date.max = 'Path `{PATH}` ({VALUE}) is after maximum allowed value ({MAX}).';
+
+msg.String = {};
+msg.String.enum = '`{VALUE}` is not a valid enum value for path `{PATH}`.';
+msg.String.match = 'Path `{PATH}` is invalid ({VALUE}).';
+msg.String.minlength = 'Path `{PATH}` (`{VALUE}`) is shorter than the minimum allowed length ({MINLENGTH}).';
+msg.String.maxlength = 'Path `{PATH}` (`{VALUE}`) is longer than the maximum allowed length ({MAXLENGTH}).';

node_modules/mongoose/lib/error/missingSchema.js

@@ -0,0 +1,31 @@
+
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+class MissingSchemaError extends MongooseError {
+  /**
+   * MissingSchema Error constructor.
+   * @param {String} name
+   * @api private
+   */
+  constructor(name) {
+    const msg = 'Schema hasn\'t been registered for model "' + name + '".\n'
+            + 'Use mongoose.model(name, schema)';
+    super(msg);
+  }
+}
+
+Object.defineProperty(MissingSchemaError.prototype, 'name', {
+  value: 'MissingSchemaError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = MissingSchemaError;

node_modules/mongoose/lib/error/mongooseError.js

@@ -0,0 +1,13 @@
+'use strict';
+
+/*!
+ * ignore
+ */
+
+class MongooseError extends Error { }
+
+Object.defineProperty(MongooseError.prototype, 'name', {
+  value: 'MongooseError'
+});
+
+module.exports = MongooseError;

node_modules/mongoose/lib/error/notFound.js

@@ -0,0 +1,45 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./');
+const util = require('util');
+
+class DocumentNotFoundError extends MongooseError {
+  /**
+   * OverwriteModel Error constructor.
+   * @api private
+   */
+  constructor(filter, model, numAffected, result) {
+    let msg;
+    const messages = MongooseError.messages;
+    if (messages.DocumentNotFoundError != null) {
+      msg = typeof messages.DocumentNotFoundError === 'function' ?
+        messages.DocumentNotFoundError(filter, model) :
+        messages.DocumentNotFoundError;
+    } else {
+      msg = 'No document found for query "' + util.inspect(filter) +
+        '" on model "' + model + '"';
+    }
+
+    super(msg);
+
+    this.result = result;
+    this.numAffected = numAffected;
+    this.filter = filter;
+    // Backwards compat
+    this.query = filter;
+  }
+}
+
+Object.defineProperty(DocumentNotFoundError.prototype, 'name', {
+  value: 'DocumentNotFoundError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = DocumentNotFoundError;

node_modules/mongoose/lib/error/objectExpected.js

@@ -0,0 +1,30 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+class ObjectExpectedError extends MongooseError {
+  /**
+   * Strict mode error constructor
+   *
+   * @param {string} type
+   * @param {string} value
+   * @api private
+   */
+  constructor(path, val) {
+    const typeDescription = Array.isArray(val) ? 'array' : 'primitive value';
+    super('Tried to set nested object field `' + path +
+      `\` to ${typeDescription} \`` + val + '`');
+    this.path = path;
+  }
+}
+
+Object.defineProperty(ObjectExpectedError.prototype, 'name', {
+  value: 'ObjectExpectedError'
+});
+
+module.exports = ObjectExpectedError;

node_modules/mongoose/lib/error/objectParameter.js

@@ -0,0 +1,30 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+class ObjectParameterError extends MongooseError {
+  /**
+   * Constructor for errors that happen when a parameter that's expected to be
+   * an object isn't an object
+   *
+   * @param {Any} value
+   * @param {String} paramName
+   * @param {String} fnName
+   * @api private
+   */
+  constructor(value, paramName, fnName) {
+    super('Parameter "' + paramName + '" to ' + fnName +
+      '() must be an object, got ' + value.toString());
+  }
+}
+
+
+Object.defineProperty(ObjectParameterError.prototype, 'name', {
+  value: 'ObjectParameterError'
+});
+
+module.exports = ObjectParameterError;

node_modules/mongoose/lib/error/overwriteModel.js

@@ -0,0 +1,30 @@
+
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+class OverwriteModelError extends MongooseError {
+  /**
+   * OverwriteModel Error constructor.
+   * @param {String} name
+   * @api private
+   */
+  constructor(name) {
+    super('Cannot overwrite `' + name + '` model once compiled.');
+  }
+}
+
+Object.defineProperty(OverwriteModelError.prototype, 'name', {
+  value: 'OverwriteModelError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = OverwriteModelError;

node_modules/mongoose/lib/error/parallelSave.js

@@ -0,0 +1,30 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./');
+
+class ParallelSaveError extends MongooseError {
+  /**
+   * ParallelSave Error constructor.
+   *
+   * @param {Document} doc
+   * @api private
+   */
+  constructor(doc) {
+    const msg = 'Can\'t save() the same doc multiple times in parallel. Document: ';
+    super(msg + doc._id);
+  }
+}
+
+Object.defineProperty(ParallelSaveError.prototype, 'name', {
+  value: 'ParallelSaveError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = ParallelSaveError;

node_modules/mongoose/lib/error/parallelValidate.js

@@ -0,0 +1,31 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./mongooseError');
+
+
+class ParallelValidateError extends MongooseError {
+  /**
+   * ParallelValidate Error constructor.
+   *
+   * @param {Document} doc
+   * @api private
+   */
+  constructor(doc) {
+    const msg = 'Can\'t validate() the same doc multiple times in parallel. Document: ';
+    super(msg + doc._id);
+  }
+}
+
+Object.defineProperty(ParallelValidateError.prototype, 'name', {
+  value: 'ParallelValidateError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = ParallelValidateError;

node_modules/mongoose/lib/error/serverSelection.js

@@ -0,0 +1,61 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./mongooseError');
+const allServersUnknown = require('../helpers/topology/allServersUnknown');
+const isAtlas = require('../helpers/topology/isAtlas');
+const isSSLError = require('../helpers/topology/isSSLError');
+
+/*!
+ * ignore
+ */
+
+const atlasMessage = 'Could not connect to any servers in your MongoDB Atlas cluster. ' +
+  'One common reason is that you\'re trying to access the database from ' +
+  'an IP that isn\'t whitelisted. Make sure your current IP address is on your Atlas ' +
+  'cluster\'s IP whitelist: https://www.mongodb.com/docs/atlas/security-whitelist/';
+
+const sslMessage = 'Mongoose is connecting with SSL enabled, but the server is ' +
+  'not accepting SSL connections. Please ensure that the MongoDB server you are ' +
+  'connecting to is configured to accept SSL connections. Learn more: ' +
+  'https://mongoosejs.com/docs/tutorials/ssl.html';
+
+class MongooseServerSelectionError extends MongooseError {
+  /**
+   * MongooseServerSelectionError constructor
+   *
+   * @api private
+   */
+  assimilateError(err) {
+    const reason = err.reason;
+    // Special message for a case that is likely due to IP whitelisting issues.
+    const isAtlasWhitelistError = isAtlas(reason) &&
+      allServersUnknown(reason) &&
+      err.message.indexOf('bad auth') === -1 &&
+      err.message.indexOf('Authentication failed') === -1;
+
+    if (isAtlasWhitelistError) {
+      this.message = atlasMessage;
+    } else if (isSSLError(reason)) {
+      this.message = sslMessage;
+    } else {
+      this.message = err.message;
+    }
+    for (const key in err) {
+      if (key !== 'name') {
+        this[key] = err[key];
+      }
+    }
+
+    return this;
+  }
+}
+
+Object.defineProperty(MongooseServerSelectionError.prototype, 'name', {
+  value: 'MongooseServerSelectionError'
+});
+
+module.exports = MongooseServerSelectionError;

node_modules/mongoose/lib/error/setOptionError.js

@@ -0,0 +1,101 @@
+/*!
+ * Module requirements
+ */
+
+'use strict';
+
+const MongooseError = require('./mongooseError');
+const util = require('util');
+const combinePathErrors = require('../helpers/error/combinePathErrors');
+
+class SetOptionError extends MongooseError {
+  /**
+   * Mongoose.set Error
+   *
+   * @api private
+   * @inherits MongooseError
+   */
+  constructor() {
+    super('');
+
+    this.errors = {};
+  }
+
+  /**
+   * Console.log helper
+   */
+  toString() {
+    return combinePathErrors(this);
+  }
+
+  /**
+   * inspect helper
+   * @api private
+   */
+  inspect() {
+    return Object.assign(new Error(this.message), this);
+  }
+
+  /**
+  * add message
+  * @param {String} key
+  * @param {String|Error} error
+  * @api private
+  */
+  addError(key, error) {
+    if (error instanceof SetOptionError) {
+      const { errors } = error;
+      for (const optionKey of Object.keys(errors)) {
+        this.addError(optionKey, errors[optionKey]);
+      }
+
+      return;
+    }
+
+    this.errors[key] = error;
+    this.message = combinePathErrors(this);
+  }
+}
+
+
+if (util.inspect.custom) {
+  // Avoid Node deprecation warning DEP0079
+  SetOptionError.prototype[util.inspect.custom] = SetOptionError.prototype.inspect;
+}
+
+/**
+ * Helper for JSON.stringify
+ * Ensure `name` and `message` show up in toJSON output re: gh-9847
+ * @api private
+ */
+Object.defineProperty(SetOptionError.prototype, 'toJSON', {
+  enumerable: false,
+  writable: false,
+  configurable: true,
+  value: function() {
+    return Object.assign({}, this, { name: this.name, message: this.message });
+  }
+});
+
+
+Object.defineProperty(SetOptionError.prototype, 'name', {
+  value: 'SetOptionError'
+});
+
+class SetOptionInnerError extends MongooseError {
+  /**
+   * Error for the "errors" array in "SetOptionError" with consistent message
+   * @param {String} key
+   */
+  constructor(key) {
+    super(`"${key}" is not a valid option to set`);
+  }
+}
+
+SetOptionError.SetOptionInnerError = SetOptionInnerError;
+
+/*!
+ * Module exports
+ */
+
+module.exports = SetOptionError;

node_modules/mongoose/lib/error/strict.js

@@ -0,0 +1,33 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+class StrictModeError extends MongooseError {
+  /**
+   * Strict mode error constructor
+   *
+   * @param {String} path
+   * @param {String} [msg]
+   * @param {Boolean} [immutable]
+   * @inherits MongooseError
+   * @api private
+   */
+  constructor(path, msg, immutable) {
+    msg = msg || 'Field `' + path + '` is not in schema and strict ' +
+      'mode is set to throw.';
+    super(msg);
+    this.isImmutableError = !!immutable;
+    this.path = path;
+  }
+}
+
+Object.defineProperty(StrictModeError.prototype, 'name', {
+  value: 'StrictModeError'
+});
+
+module.exports = StrictModeError;

node_modules/mongoose/lib/error/strictPopulate.js

@@ -0,0 +1,29 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+class StrictPopulateError extends MongooseError {
+  /**
+   * Strict mode error constructor
+   *
+   * @param {String} path
+   * @param {String} [msg]
+   * @inherits MongooseError
+   * @api private
+   */
+  constructor(path, msg) {
+    msg = msg || 'Cannot populate path `' + path + '` because it is not in your schema. ' + 'Set the `strictPopulate` option to false to override.';
+    super(msg);
+    this.path = path;
+  }
+}
+
+Object.defineProperty(StrictPopulateError.prototype, 'name', {
+  value: 'StrictPopulateError'
+});
+
+module.exports = StrictPopulateError;

node_modules/mongoose/lib/error/syncIndexes.js

@@ -0,0 +1,30 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./mongooseError');
+
+/**
+ * SyncIndexes Error constructor.
+ *
+ * @param {String} message
+ * @param {String} errorsMap
+ * @inherits MongooseError
+ * @api private
+ */
+
+class SyncIndexesError extends MongooseError {
+  constructor(message, errorsMap) {
+    super(message);
+    this.errors = errorsMap;
+  }
+}
+
+Object.defineProperty(SyncIndexesError.prototype, 'name', {
+  value: 'SyncIndexesError'
+});
+
+
+module.exports = SyncIndexesError;

node_modules/mongoose/lib/error/validation.js

@@ -0,0 +1,103 @@
+/*!
+ * Module requirements
+ */
+
+'use strict';
+
+const MongooseError = require('./mongooseError');
+const getConstructorName = require('../helpers/getConstructorName');
+const util = require('util');
+const combinePathErrors = require('../helpers/error/combinePathErrors');
+
+class ValidationError extends MongooseError {
+  /**
+   * Document Validation Error
+   *
+   * @api private
+   * @param {Document} [instance]
+   * @inherits MongooseError
+   */
+  constructor(instance) {
+    let _message;
+    if (getConstructorName(instance) === 'model') {
+      _message = instance.constructor.modelName + ' validation failed';
+    } else {
+      _message = 'Validation failed';
+    }
+
+    super(_message);
+
+    this.errors = {};
+    this._message = _message;
+
+    if (instance) {
+      instance.$errors = this.errors;
+    }
+  }
+
+  /**
+   * Console.log helper
+   */
+  toString() {
+    return this.name + ': ' + combinePathErrors(this);
+  }
+
+  /**
+   * inspect helper
+   * @api private
+   */
+  inspect() {
+    return Object.assign(new Error(this.message), this);
+  }
+
+  /**
+  * add message
+  * @param {String} path
+  * @param {String|Error} error
+  * @api private
+  */
+  addError(path, error) {
+    if (error instanceof ValidationError) {
+      const { errors } = error;
+      for (const errorPath of Object.keys(errors)) {
+        this.addError(`${path}.${errorPath}`, errors[errorPath]);
+      }
+
+      return;
+    }
+
+    this.errors[path] = error;
+    this.message = this._message + ': ' + combinePathErrors(this);
+  }
+}
+
+
+if (util.inspect.custom) {
+  // Avoid Node deprecation warning DEP0079
+  ValidationError.prototype[util.inspect.custom] = ValidationError.prototype.inspect;
+}
+
+/**
+ * Helper for JSON.stringify
+ * Ensure `name` and `message` show up in toJSON output re: gh-9847
+ * @api private
+ */
+Object.defineProperty(ValidationError.prototype, 'toJSON', {
+  enumerable: false,
+  writable: false,
+  configurable: true,
+  value: function() {
+    return Object.assign({}, this, { name: this.name, message: this.message });
+  }
+});
+
+
+Object.defineProperty(ValidationError.prototype, 'name', {
+  value: 'ValidationError'
+});
+
+/*!
+ * Module exports
+ */
+
+module.exports = ValidationError;

node_modules/mongoose/lib/error/validator.js

@@ -0,0 +1,99 @@
+/*!
+ * Module dependencies.
+ */
+
+'use strict';
+
+const MongooseError = require('./');
+
+
+class ValidatorError extends MongooseError {
+  /**
+   * Schema validator error
+   *
+   * @param {Object} properties
+   * @param {Document} doc
+   * @api private
+   */
+  constructor(properties, doc) {
+    let msg = properties.message;
+    if (!msg) {
+      msg = MongooseError.messages.general.default;
+    }
+
+    const message = formatMessage(msg, properties, doc);
+    super(message);
+
+    properties = Object.assign({}, properties, { message: message });
+    this.properties = properties;
+    this.kind = properties.type;
+    this.path = properties.path;
+    this.value = properties.value;
+    this.reason = properties.reason;
+  }
+
+  /**
+   * toString helper
+   * TODO remove? This defaults to `${this.name}: ${this.message}`
+   * @api private
+   */
+  toString() {
+    return this.message;
+  }
+
+  /**
+   * Ensure `name` and `message` show up in toJSON output re: gh-9296
+   * @api private
+   */
+
+  toJSON() {
+    return Object.assign({ name: this.name, message: this.message }, this);
+  }
+}
+
+
+Object.defineProperty(ValidatorError.prototype, 'name', {
+  value: 'ValidatorError'
+});
+
+/**
+ * The object used to define this validator. Not enumerable to hide
+ * it from `require('util').inspect()` output re: gh-3925
+ * @api private
+ */
+
+Object.defineProperty(ValidatorError.prototype, 'properties', {
+  enumerable: false,
+  writable: true,
+  value: null
+});
+
+// Exposed for testing
+ValidatorError.prototype.formatMessage = formatMessage;
+
+/**
+ * Formats error messages
+ * @api private
+ */
+
+function formatMessage(msg, properties, doc) {
+  if (typeof msg === 'function') {
+    return msg(properties, doc);
+  }
+
+  const propertyNames = Object.keys(properties);
+  for (const propertyName of propertyNames) {
+    if (propertyName === 'message') {
+      continue;
+    }
+    msg = msg.replace('{' + propertyName.toUpperCase() + '}', properties[propertyName]);
+  }
+
+  return msg;
+}
+
+/*!
+ * exports
+ */
+
+module.exports = ValidatorError;

node_modules/mongoose/lib/error/version.js

@@ -0,0 +1,36 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const MongooseError = require('./');
+
+class VersionError extends MongooseError {
+  /**
+   * Version Error constructor.
+   *
+   * @param {Document} doc
+   * @param {Number} currentVersion
+   * @param {Array<String>} modifiedPaths
+   * @api private
+   */
+  constructor(doc, currentVersion, modifiedPaths) {
+    const modifiedPathsStr = modifiedPaths.join(', ');
+    super('No matching document found for id "' + doc._id +
+      '" version ' + currentVersion + ' modifiedPaths "' + modifiedPathsStr + '"');
+    this.version = currentVersion;
+    this.modifiedPaths = modifiedPaths;
+  }
+}
+
+
+Object.defineProperty(VersionError.prototype, 'name', {
+  value: 'VersionError'
+});
+
+/*!
+ * exports
+ */
+
+module.exports = VersionError;

node_modules/mongoose/lib/helpers/aggregate/prepareDiscriminatorPipeline.js

@@ -0,0 +1,39 @@
+'use strict';
+
+module.exports = function prepareDiscriminatorPipeline(pipeline, schema, prefix) {
+  const discriminatorMapping = schema && schema.discriminatorMapping;
+  prefix = prefix || '';
+
+  if (discriminatorMapping && !discriminatorMapping.isRoot) {
+    const originalPipeline = pipeline;
+    const filterKey = (prefix.length > 0 ? prefix + '.' : prefix) + discriminatorMapping.key;
+    const discriminatorValue = discriminatorMapping.value;
+
+    // If the first pipeline stage is a match and it doesn't specify a `__t`
+    // key, add the discriminator key to it. This allows for potential
+    // aggregation query optimizations not to be disturbed by this feature.
+    if (originalPipeline[0] != null &&
+        originalPipeline[0].$match &&
+        (originalPipeline[0].$match[filterKey] === undefined || originalPipeline[0].$match[filterKey] === discriminatorValue)) {
+      originalPipeline[0].$match[filterKey] = discriminatorValue;
+      // `originalPipeline` is a ref, so there's no need for
+      // aggregate._pipeline = originalPipeline
+    } else if (originalPipeline[0] != null && originalPipeline[0].$geoNear) {
+      originalPipeline[0].$geoNear.query =
+          originalPipeline[0].$geoNear.query || {};
+      originalPipeline[0].$geoNear.query[filterKey] = discriminatorValue;
+    } else if (originalPipeline[0] != null && originalPipeline[0].$search) {
+      if (originalPipeline[1] && originalPipeline[1].$match != null) {
+        originalPipeline[1].$match[filterKey] = originalPipeline[1].$match[filterKey] || discriminatorValue;
+      } else {
+        const match = {};
+        match[filterKey] = discriminatorValue;
+        originalPipeline.splice(1, 0, { $match: match });
+      }
+    } else {
+      const match = {};
+      match[filterKey] = discriminatorValue;
+      originalPipeline.unshift({ $match: match });
+    }
+  }
+};

node_modules/mongoose/lib/helpers/aggregate/stringifyFunctionOperators.js

@@ -0,0 +1,50 @@
+'use strict';
+
+module.exports = function stringifyFunctionOperators(pipeline) {
+  if (!Array.isArray(pipeline)) {
+    return;
+  }
+
+  for (const stage of pipeline) {
+    if (stage == null) {
+      continue;
+    }
+
+    const canHaveAccumulator = stage.$group || stage.$bucket || stage.$bucketAuto;
+    if (canHaveAccumulator != null) {
+      for (const key of Object.keys(canHaveAccumulator)) {
+        handleAccumulator(canHaveAccumulator[key]);
+      }
+    }
+
+    const stageType = Object.keys(stage)[0];
+    if (stageType && typeof stage[stageType] === 'object') {
+      const stageOptions = stage[stageType];
+      for (const key of Object.keys(stageOptions)) {
+        if (stageOptions[key] != null &&
+            stageOptions[key].$function != null &&
+            typeof stageOptions[key].$function.body === 'function') {
+          stageOptions[key].$function.body = stageOptions[key].$function.body.toString();
+        }
+      }
+    }
+
+    if (stage.$facet != null) {
+      for (const key of Object.keys(stage.$facet)) {
+        stringifyFunctionOperators(stage.$facet[key]);
+      }
+    }
+  }
+};
+
+function handleAccumulator(operator) {
+  if (operator == null || operator.$accumulator == null) {
+    return;
+  }
+
+  for (const key of ['init', 'accumulate', 'merge', 'finalize']) {
+    if (typeof operator.$accumulator[key] === 'function') {
+      operator.$accumulator[key] = String(operator.$accumulator[key]);
+    }
+  }
+}

node_modules/mongoose/lib/helpers/arrayDepth.js

@@ -0,0 +1,33 @@
+'use strict';
+
+module.exports = arrayDepth;
+
+function arrayDepth(arr) {
+  if (!Array.isArray(arr)) {
+    return { min: 0, max: 0, containsNonArrayItem: true };
+  }
+  if (arr.length === 0) {
+    return { min: 1, max: 1, containsNonArrayItem: false };
+  }
+  if (arr.length === 1 && !Array.isArray(arr[0])) {
+    return { min: 1, max: 1, containsNonArrayItem: false };
+  }
+
+  const res = arrayDepth(arr[0]);
+
+  for (let i = 1; i < arr.length; ++i) {
+    const _res = arrayDepth(arr[i]);
+    if (_res.min < res.min) {
+      res.min = _res.min;
+    }
+    if (_res.max > res.max) {
+      res.max = _res.max;
+    }
+    res.containsNonArrayItem = res.containsNonArrayItem || _res.containsNonArrayItem;
+  }
+
+  res.min = res.min + 1;
+  res.max = res.max + 1;
+
+  return res;
+}

node_modules/mongoose/lib/helpers/clone.js

@@ -0,0 +1,177 @@
+'use strict';
+
+const Decimal = require('../types/decimal128');
+const ObjectId = require('../types/objectid');
+const specialProperties = require('./specialProperties');
+const isMongooseObject = require('./isMongooseObject');
+const getFunctionName = require('./getFunctionName');
+const isBsonType = require('./isBsonType');
+const isMongooseArray = require('../types/array/isMongooseArray').isMongooseArray;
+const isObject = require('./isObject');
+const isPOJO = require('./isPOJO');
+const symbols = require('./symbols');
+const trustedSymbol = require('./query/trusted').trustedSymbol;
+
+/**
+ * Object clone with Mongoose natives support.
+ *
+ * If options.minimize is true, creates a minimal data object. Empty objects and undefined values will not be cloned. This makes the data payload sent to MongoDB as small as possible.
+ *
+ * Functions are never cloned.
+ *
+ * @param {Object} obj the object to clone
+ * @param {Object} options
+ * @param {Boolean} isArrayChild true if cloning immediately underneath an array. Special case for minimize.
+ * @return {Object} the cloned object
+ * @api private
+ */
+
+function clone(obj, options, isArrayChild) {
+  if (obj == null) {
+    return obj;
+  }
+
+  if (Array.isArray(obj)) {
+    return cloneArray(isMongooseArray(obj) ? obj.__array : obj, options);
+  }
+
+  if (isMongooseObject(obj)) {
+    // Single nested subdocs should apply getters later in `applyGetters()`
+    // when calling `toObject()`. See gh-7442, gh-8295
+    if (options && options._skipSingleNestedGetters && obj.$isSingleNested) {
+      options = Object.assign({}, options, { getters: false });
+    }
+    const isSingleNested = obj.$isSingleNested;
+
+    if (isPOJO(obj) && obj.$__ != null && obj._doc != null) {
+      return obj._doc;
+    }
+
+    let ret;
+    if (options && options.json && typeof obj.toJSON === 'function') {
+      ret = obj.toJSON(options);
+    } else {
+      ret = obj.toObject(options);
+    }
+
+    if (options && options.minimize && isSingleNested && Object.keys(ret).length === 0) {
+      return undefined;
+    }
+
+    return ret;
+  }
+
+  const objConstructor = obj.constructor;
+
+  if (objConstructor) {
+    switch (getFunctionName(objConstructor)) {
+      case 'Object':
+        return cloneObject(obj, options, isArrayChild);
+      case 'Date':
+        return new objConstructor(+obj);
+      case 'RegExp':
+        return cloneRegExp(obj);
+      default:
+        // ignore
+        break;
+    }
+  }
+
+  if (isBsonType(obj, 'ObjectId')) {
+    return new ObjectId(obj.id);
+  }
+
+  if (isBsonType(obj, 'Decimal128')) {
+    if (options && options.flattenDecimals) {
+      return obj.toJSON();
+    }
+    return Decimal.fromString(obj.toString());
+  }
+
+  // object created with Object.create(null)
+  if (!objConstructor && isObject(obj)) {
+    return cloneObject(obj, options, isArrayChild);
+  }
+
+  if (typeof obj === 'object' && obj[symbols.schemaTypeSymbol]) {
+    return obj.clone();
+  }
+
+  // If we're cloning this object to go into a MongoDB command,
+  // and there's a `toBSON()` function, assume this object will be
+  // stored as a primitive in MongoDB and doesn't need to be cloned.
+  if (options && options.bson && typeof obj.toBSON === 'function') {
+    return obj;
+  }
+
+  if (typeof obj.valueOf === 'function') {
+    return obj.valueOf();
+  }
+
+  return cloneObject(obj, options, isArrayChild);
+}
+module.exports = clone;
+
+/*!
+ * ignore
+ */
+
+function cloneObject(obj, options, isArrayChild) {
+  const minimize = options && options.minimize;
+  const omitUndefined = options && options.omitUndefined;
+  const seen = options && options._seen;
+  const ret = {};
+  let hasKeys;
+
+  if (seen && seen.has(obj)) {
+    return seen.get(obj);
+  } else if (seen) {
+    seen.set(obj, ret);
+  }
+  if (trustedSymbol in obj) {
+    ret[trustedSymbol] = obj[trustedSymbol];
+  }
+
+  let i = 0;
+  let key = '';
+  const keys = Object.keys(obj);
+  const len = keys.length;
+
+  for (i = 0; i < len; ++i) {
+    if (specialProperties.has(key = keys[i])) {
+      continue;
+    }
+
+    // Don't pass `isArrayChild` down
+    const val = clone(obj[key], options, false);
+
+    if ((minimize === false || omitUndefined) && typeof val === 'undefined') {
+      delete ret[key];
+    } else if (minimize !== true || (typeof val !== 'undefined')) {
+      hasKeys || (hasKeys = true);
+      ret[key] = val;
+    }
+  }
+
+  return minimize && !isArrayChild ? hasKeys && ret : ret;
+}
+
+function cloneArray(arr, options) {
+  let i = 0;
+  const len = arr.length;
+  const ret = new Array(len);
+  for (i = 0; i < len; ++i) {
+    ret[i] = clone(arr[i], options, true);
+  }
+
+  return ret;
+}
+
+function cloneRegExp(regexp) {
+  const ret = new RegExp(regexp.source, regexp.flags);
+
+  if (ret.lastIndex !== regexp.lastIndex) {
+    ret.lastIndex = regexp.lastIndex;
+  }
+  return ret;
+}

node_modules/mongoose/lib/helpers/common.js

@@ -0,0 +1,127 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const Binary = require('bson').Binary;
+const isBsonType = require('./isBsonType');
+const isMongooseObject = require('./isMongooseObject');
+const MongooseError = require('../error');
+const util = require('util');
+
+exports.flatten = flatten;
+exports.modifiedPaths = modifiedPaths;
+
+/*!
+ * ignore
+ */
+
+function flatten(update, path, options, schema) {
+  let keys;
+  if (update && isMongooseObject(update) && !Buffer.isBuffer(update)) {
+    keys = Object.keys(update.toObject({ transform: false, virtuals: false }) || {});
+  } else {
+    keys = Object.keys(update || {});
+  }
+
+  const numKeys = keys.length;
+  const result = {};
+  path = path ? path + '.' : '';
+
+  for (let i = 0; i < numKeys; ++i) {
+    const key = keys[i];
+    const val = update[key];
+    result[path + key] = val;
+
+    // Avoid going into mixed paths if schema is specified
+    const keySchema = schema && schema.path && schema.path(path + key);
+    const isNested = schema && schema.nested && schema.nested[path + key];
+    if (keySchema && keySchema.instance === 'Mixed') continue;
+
+    if (shouldFlatten(val)) {
+      if (options && options.skipArrays && Array.isArray(val)) {
+        continue;
+      }
+      const flat = flatten(val, path + key, options, schema);
+      for (const k in flat) {
+        result[k] = flat[k];
+      }
+      if (Array.isArray(val)) {
+        result[path + key] = val;
+      }
+    }
+
+    if (isNested) {
+      const paths = Object.keys(schema.paths);
+      for (const p of paths) {
+        if (p.startsWith(path + key + '.') && !result.hasOwnProperty(p)) {
+          result[p] = void 0;
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+/*!
+ * ignore
+ */
+
+function modifiedPaths(update, path, result, recursion = null) {
+  if (update == null || typeof update !== 'object') {
+    return;
+  }
+
+  if (recursion == null) {
+    recursion = {
+      raw: { update, path },
+      trace: new WeakSet()
+    };
+  }
+
+  if (recursion.trace.has(update)) {
+    throw new MongooseError(`a circular reference in the update value, updateValue:
+${util.inspect(recursion.raw.update, { showHidden: false, depth: 1 })}
+updatePath: '${recursion.raw.path}'`);
+  }
+  recursion.trace.add(update);
+
+  const keys = Object.keys(update || {});
+  const numKeys = keys.length;
+  result = result || {};
+  path = path ? path + '.' : '';
+
+  for (let i = 0; i < numKeys; ++i) {
+    const key = keys[i];
+    let val = update[key];
+
+    const _path = path + key;
+    result[_path] = true;
+    if (!Buffer.isBuffer(val) && isMongooseObject(val)) {
+      val = val.toObject({ transform: false, virtuals: false });
+    }
+    if (shouldFlatten(val)) {
+      modifiedPaths(val, path + key, result, recursion);
+    }
+  }
+  recursion.trace.delete(update);
+
+  return result;
+}
+
+/*!
+ * ignore
+ */
+
+function shouldFlatten(val) {
+  return val &&
+      typeof val === 'object' &&
+      !(val instanceof Date) &&
+      !isBsonType(val, 'ObjectId') &&
+      (!Array.isArray(val) || val.length !== 0) &&
+      !(val instanceof Buffer) &&
+      !isBsonType(val, 'Decimal128') &&
+      !(val instanceof Binary);
+}

node_modules/mongoose/lib/helpers/cursor/eachAsync.js

@@ -0,0 +1,225 @@
+'use strict';
+
+/*!
+ * Module dependencies.
+ */
+
+const EachAsyncMultiError = require('../../error/eachAsyncMultiError');
+const immediate = require('../immediate');
+
+/**
+ * Execute `fn` for every document in the cursor. If `fn` returns a promise,
+ * will wait for the promise to resolve before iterating on to the next one.
+ * Returns a promise that resolves when done.
+ *
+ * @param {Function} next the thunk to call to get the next document
+ * @param {Function} fn
+ * @param {Object} options
+ * @param {Number} [options.batchSize=null] if set, Mongoose will call `fn` with an array of at most `batchSize` documents, instead of a single document
+ * @param {Number} [options.parallel=1] maximum number of `fn` calls that Mongoose will run in parallel
+ * @param {AbortSignal} [options.signal] allow cancelling this eachAsync(). Once the abort signal is fired, `eachAsync()` will immediately fulfill the returned promise (or call the callback) and not fetch any more documents.
+ * @return {Promise}
+ * @api public
+ * @method eachAsync
+ */
+
+module.exports = async function eachAsync(next, fn, options) {
+  const parallel = options.parallel || 1;
+  const batchSize = options.batchSize;
+  const signal = options.signal;
+  const continueOnError = options.continueOnError;
+  const aggregatedErrors = [];
+  const enqueue = asyncQueue();
+
+  let aborted = false;
+
+  return new Promise((resolve, reject) => {
+    if (signal != null) {
+      if (signal.aborted) {
+        return resolve(null);
+      }
+
+      signal.addEventListener('abort', () => {
+        aborted = true;
+        return resolve(null);
+      }, { once: true });
+    }
+
+    if (batchSize != null) {
+      if (typeof batchSize !== 'number') {
+        throw new TypeError('batchSize must be a number');
+      } else if (!Number.isInteger(batchSize)) {
+        throw new TypeError('batchSize must be an integer');
+      } else if (batchSize < 1) {
+        throw new TypeError('batchSize must be at least 1');
+      }
+    }
+
+    iterate((err, res) => {
+      if (err != null) {
+        return reject(err);
+      }
+      resolve(res);
+    });
+  });
+
+  function iterate(finalCallback) {
+    let handleResultsInProgress = 0;
+    let currentDocumentIndex = 0;
+
+    let error = null;
+    for (let i = 0; i < parallel; ++i) {
+      enqueue(createFetch());
+    }
+
+    function createFetch() {
+      let documentsBatch = [];
+      let drained = false;
+
+      return fetch;
+
+      function fetch(done) {
+        if (drained || aborted) {
+          return done();
+        } else if (error) {
+          return done();
+        }
+
+        next(function(err, doc) {
+          if (error != null) {
+            return done();
+          }
+          if (err != null) {
+            if (err.name === 'MongoCursorExhaustedError') {
+              // We may end up calling `next()` multiple times on an exhausted
+              // cursor, which leads to an error. In case cursor is exhausted,
+              // just treat it as if the cursor returned no document, which is
+              // how a cursor indicates it is exhausted.
+              doc = null;
+            } else if (continueOnError) {
+              aggregatedErrors.push(err);
+            } else {
+              error = err;
+              finalCallback(err);
+              return done();
+            }
+          }
+          if (doc == null) {
+            drained = true;
+            if (handleResultsInProgress <= 0) {
+              const finalErr = continueOnError ?
+                createEachAsyncMultiError(aggregatedErrors) :
+                error;
+
+              finalCallback(finalErr);
+            } else if (batchSize && documentsBatch.length) {
+              handleNextResult(documentsBatch, currentDocumentIndex++, handleNextResultCallBack);
+            }
+            return done();
+          }
+
+          ++handleResultsInProgress;
+
+          // Kick off the subsequent `next()` before handling the result, but
+          // make sure we know that we still have a result to handle re: #8422
+          immediate(() => done());
+
+          if (batchSize) {
+            documentsBatch.push(doc);
+          }
+
+          // If the current documents size is less than the provided batch size don't process the documents yet
+          if (batchSize && documentsBatch.length !== batchSize) {
+            immediate(() => enqueue(fetch));
+            return;
+          }
+
+          const docsToProcess = batchSize ? documentsBatch : doc;
+
+          function handleNextResultCallBack(err) {
+            if (batchSize) {
+              handleResultsInProgress -= documentsBatch.length;
+              documentsBatch = [];
+            } else {
+              --handleResultsInProgress;
+            }
+            if (err != null) {
+              if (continueOnError) {
+                aggregatedErrors.push(err);
+              } else {
+                error = err;
+                return finalCallback(err);
+              }
+            }
+            if ((drained || aborted) && handleResultsInProgress <= 0) {
+              const finalErr = continueOnError ?
+                createEachAsyncMultiError(aggregatedErrors) :
+                error;
+              return finalCallback(finalErr);
+            }
+
+            immediate(() => enqueue(fetch));
+          }
+
+          handleNextResult(docsToProcess, currentDocumentIndex++, handleNextResultCallBack);
+        });
+      }
+    }
+  }
+
+  function handleNextResult(doc, i, callback) {
+    let maybePromise;
+    try {
+      maybePromise = fn(doc, i);
+    } catch (err) {
+      return callback(err);
+    }
+    if (maybePromise && typeof maybePromise.then === 'function') {
+      maybePromise.then(
+        function() { callback(null); },
+        function(error) {
+          callback(error || new Error('`eachAsync()` promise rejected without error'));
+        });
+    } else {
+      callback(null);
+    }
+  }
+};
+
+// `next()` can only execute one at a time, so make sure we always execute
+// `next()` in series, while still allowing multiple `fn()` instances to run
+// in parallel.
+function asyncQueue() {
+  const _queue = [];
+  let inProgress = null;
+  let id = 0;
+
+  return function enqueue(fn) {
+    if (
+      inProgress === null &&
+      _queue.length === 0
+    ) {
+      inProgress = id++;
+      return fn(_step);
+    }
+    _queue.push(fn);
+  };
+
+  function _step() {
+    if (_queue.length !== 0) {
+      inProgress = id++;
+      const fn = _queue.shift();
+      fn(_step);
+    } else {
+      inProgress = null;
+    }
+  }
+}
+
+function createEachAsyncMultiError(aggregatedErrors) {
+  if (aggregatedErrors.length === 0) {
+    return null;
+  }
+
+  return new EachAsyncMultiError(aggregatedErrors);
+}

node_modules/mongoose/lib/helpers/discriminator/areDiscriminatorValuesEqual.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const isBsonType = require('../isBsonType');
+
+module.exports = function areDiscriminatorValuesEqual(a, b) {
+  if (typeof a === 'string' && typeof b === 'string') {
+    return a === b;
+  }
+  if (typeof a === 'number' && typeof b === 'number') {
+    return a === b;
+  }
+  if (isBsonType(a, 'ObjectId') && isBsonType(b, 'ObjectId')) {
+    return a.toString() === b.toString();
+  }
+  return false;
+};

node_modules/mongoose/lib/helpers/discriminator/checkEmbeddedDiscriminatorKeyProjection.js

@@ -0,0 +1,12 @@
+'use strict';
+
+module.exports = function checkEmbeddedDiscriminatorKeyProjection(userProjection, path, schema, selected, addedPaths) {
+  const userProjectedInPath = Object.keys(userProjection).
+    reduce((cur, key) => cur || key.startsWith(path + '.'), false);
+  const _discriminatorKey = path + '.' + schema.options.discriminatorKey;
+  if (!userProjectedInPath &&
+      addedPaths.length === 1 &&
+      addedPaths[0] === _discriminatorKey) {
+    selected.splice(selected.indexOf(_discriminatorKey), 1);
+  }
+};

node_modules/mongoose/lib/helpers/discriminator/getConstructor.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const getDiscriminatorByValue = require('./getDiscriminatorByValue');
+
+/**
+ * Find the correct constructor, taking into account discriminators
+ * @api private
+ */
+
+module.exports = function getConstructor(Constructor, value) {
+  const discriminatorKey = Constructor.schema.options.discriminatorKey;
+  if (value != null &&
+      Constructor.discriminators &&
+      value[discriminatorKey] != null) {
+    if (Constructor.discriminators[value[discriminatorKey]]) {
+      Constructor = Constructor.discriminators[value[discriminatorKey]];
+    } else {
+      const constructorByValue = getDiscriminatorByValue(Constructor.discriminators, value[discriminatorKey]);
+      if (constructorByValue) {
+        Constructor = constructorByValue;
+      }
+    }
+  }
+
+  return Constructor;
+};

node_modules/mongoose/lib/helpers/discriminator/getDiscriminatorByValue.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const areDiscriminatorValuesEqual = require('./areDiscriminatorValuesEqual');
+
+/**
+ * returns discriminator by discriminatorMapping.value
+ *
+ * @param {Object} discriminators
+ * @param {string} value
+ * @api private
+ */
+
+module.exports = function getDiscriminatorByValue(discriminators, value) {
+  if (discriminators == null) {
+    return null;
+  }
+  for (const name of Object.keys(discriminators)) {
+    const it = discriminators[name];
+    if (
+      it.schema &&
+      it.schema.discriminatorMapping &&
+      areDiscriminatorValuesEqual(it.schema.discriminatorMapping.value, value)
+    ) {
+      return it;
+    }
+  }
+  return null;
+};

node_modules/mongoose/lib/helpers/discriminator/getSchemaDiscriminatorByValue.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const areDiscriminatorValuesEqual = require('./areDiscriminatorValuesEqual');
+
+/**
+ * returns discriminator by discriminatorMapping.value
+ *
+ * @param {Schema} schema
+ * @param {string} value
+ * @api private
+ */
+
+module.exports = function getSchemaDiscriminatorByValue(schema, value) {
+  if (schema == null || schema.discriminators == null) {
+    return null;
+  }
+  for (const key of Object.keys(schema.discriminators)) {
+    const discriminatorSchema = schema.discriminators[key];
+    if (discriminatorSchema.discriminatorMapping == null) {
+      continue;
+    }
+    if (areDiscriminatorValuesEqual(discriminatorSchema.discriminatorMapping.value, value)) {
+      return discriminatorSchema;
+    }
+  }
+  return null;
+};

node_modules/mongoose/lib/helpers/discriminator/mergeDiscriminatorSchema.js

@@ -0,0 +1,75 @@
+'use strict';
+const schemaMerge = require('../schema/merge');
+const specialProperties = require('../../helpers/specialProperties');
+const isBsonType = require('../../helpers/isBsonType');
+const ObjectId = require('../../types/objectid');
+const isObject = require('../../helpers/isObject');
+/**
+ * Merges `from` into `to` without overwriting existing properties.
+ *
+ * @param {Object} to
+ * @param {Object} from
+ * @param {String} [path]
+ * @api private
+ */
+
+module.exports = function mergeDiscriminatorSchema(to, from, path, seen) {
+  const keys = Object.keys(from);
+  let i = 0;
+  const len = keys.length;
+  let key;
+
+  path = path || '';
+  seen = seen || new WeakSet();
+
+  if (seen.has(from)) {
+    return;
+  }
+  seen.add(from);
+
+  while (i < len) {
+    key = keys[i++];
+    if (!path) {
+      if (key === 'discriminators' ||
+        key === 'base' ||
+        key === '_applyDiscriminators' ||
+        key === '_userProvidedOptions' ||
+        key === 'options') {
+        continue;
+      }
+    }
+    if (path === 'tree' && from != null && from.instanceOfSchema) {
+      continue;
+    }
+    if (specialProperties.has(key)) {
+      continue;
+    }
+    if (to[key] == null) {
+      to[key] = from[key];
+    } else if (isObject(from[key])) {
+      if (!isObject(to[key])) {
+        to[key] = {};
+      }
+      if (from[key] != null) {
+        // Skip merging schemas if we're creating a discriminator schema and
+        // base schema has a given path as a single nested but discriminator schema
+        // has the path as a document array, or vice versa (gh-9534)
+        if ((from[key].$isSingleNested && to[key].$isMongooseDocumentArray) ||
+              (from[key].$isMongooseDocumentArray && to[key].$isSingleNested)) {
+          continue;
+        } else if (from[key].instanceOfSchema) {
+          if (to[key].instanceOfSchema) {
+            schemaMerge(to[key], from[key].clone(), true);
+          } else {
+            to[key] = from[key].clone();
+          }
+          continue;
+        } else if (isBsonType(from[key], 'ObjectId')) {
+          to[key] = new ObjectId(from[key]);
+          continue;
+        }
+      }
+      mergeDiscriminatorSchema(to[key], from[key], path ? path + '.' + key : key, seen);
+    }
+  }
+};

node_modules/mongoose/lib/helpers/document/applyDefaults.js

@@ -0,0 +1,126 @@
+'use strict';
+
+module.exports = function applyDefaults(doc, fields, exclude, hasIncludedChildren, isBeforeSetters, pathsToSkip) {
+  const paths = Object.keys(doc.$__schema.paths);
+  const plen = paths.length;
+
+  for (let i = 0; i < plen; ++i) {
+    let def;
+    let curPath = '';
+    const p = paths[i];
+
+    if (p === '_id' && doc.$__.skipId) {
+      continue;
+    }
+
+    const type = doc.$__schema.paths[p];
+    const path = type.splitPath();
+    const len = path.length;
+    let included = false;
+    let doc_ = doc._doc;
+    for (let j = 0; j < len; ++j) {
+      if (doc_ == null) {
+        break;
+      }
+
+      const piece = path[j];
+      curPath += (!curPath.length ? '' : '.') + piece;
+
+      if (exclude === true) {
+        if (curPath in fields) {
+          break;
+        }
+      } else if (exclude === false && fields && !included) {
+        const hasSubpaths = type.$isSingleNested || type.$isMongooseDocumentArray;
+        if (curPath in fields || (j === len - 1 && hasSubpaths && hasIncludedChildren != null && hasIncludedChildren[curPath])) {
+          included = true;
+        } else if (hasIncludedChildren != null && !hasIncludedChildren[curPath]) {
+          break;
+        }
+      }
+
+      if (j === len - 1) {
+        if (doc_[piece] !== void 0) {
+          break;
+        }
+
+        if (isBeforeSetters != null) {
+          if (typeof type.defaultValue === 'function') {
+            if (!type.defaultValue.$runBeforeSetters && isBeforeSetters) {
+              break;
+            }
+            if (type.defaultValue.$runBeforeSetters && !isBeforeSetters) {
+              break;
+            }
+          } else if (!isBeforeSetters) {
+            // Non-function defaults should always run **before** setters
+            continue;
+          }
+        }
+
+        if (pathsToSkip && pathsToSkip[curPath]) {
+          break;
+        }
+
+        if (fields && exclude !== null) {
+          if (exclude === true) {
+            // apply defaults to all non-excluded fields
+            if (p in fields) {
+              continue;
+            }
+
+            try {
+              def = type.getDefault(doc, false);
+            } catch (err) {
+              doc.invalidate(p, err);
+              break;
+            }
+
+            if (typeof def !== 'undefined') {
+              doc_[piece] = def;
+              applyChangeTracking(doc, p);
+            }
+          } else if (included) {
+            // selected field
+            try {
+              def = type.getDefault(doc, false);
+            } catch (err) {
+              doc.invalidate(p, err);
+              break;
+            }
+
+            if (typeof def !== 'undefined') {
+              doc_[piece] = def;
+              applyChangeTracking(doc, p);
+            }
+          }
+        } else {
+          try {
+            def = type.getDefault(doc, false);
+          } catch (err) {
+            doc.invalidate(p, err);
+            break;
+          }
+
+          if (typeof def !== 'undefined') {
+            doc_[piece] = def;
+            applyChangeTracking(doc, p);
+          }
+        }
+      } else {
+        doc_ = doc_[piece];
+      }
+    }
+  }
+};
+
+/*!
+ * ignore
+ */
+
+function applyChangeTracking(doc, fullPath) {
+  doc.$__.activePaths.default(fullPath);
+  if (doc.$isSubdocument && doc.$isSingleNested && doc.$parent() != null) {
+    doc.$parent().$__.activePaths.default(doc.$__pathRelativeToParent(fullPath));
+  }
+}

node_modules/mongoose/lib/helpers/document/cleanModifiedSubpaths.js

@@ -0,0 +1,35 @@
+'use strict';
+
+/*!
+ * ignore
+ */
+
+module.exports = function cleanModifiedSubpaths(doc, path, options) {
+  options = options || {};
+  const skipDocArrays = options.skipDocArrays;
+
+  let deleted = 0;
+  if (!doc) {
+    return deleted;
+  }
+
+  for (const modifiedPath of Object.keys(doc.$__.activePaths.getStatePaths('modify'))) {
+    if (skipDocArrays) {
+      const schemaType = doc.$__schema.path(modifiedPath);
+      if (schemaType && schemaType.$isMongooseDocumentArray) {
+        continue;
+      }
+    }
+    if (modifiedPath.startsWith(path + '.')) {
+      doc.$__.activePaths.clearPath(modifiedPath);
+      ++deleted;
+
+      if (doc.$isSubdocument) {
+        const owner = doc.ownerDocument();
+        const fullPath = doc.$__fullPath(modifiedPath);
+        owner.$__.activePaths.clearPath(fullPath);
+      }
+    }
+  }
+  return deleted;
+};

node_modules/mongoose/lib/helpers/document/compile.js

@@ -0,0 +1,228 @@
+'use strict';
+
+const clone = require('../../helpers/clone');
+const documentSchemaSymbol = require('../../helpers/symbols').documentSchemaSymbol;
+const internalToObjectOptions = require('../../options').internalToObjectOptions;
+const utils = require('../../utils');
+
+let Document;
+const getSymbol = require('../../helpers/symbols').getSymbol;
+const scopeSymbol = require('../../helpers/symbols').scopeSymbol;
+
+const isPOJO = utils.isPOJO;
+
+/*!
+ * exports
+ */
+
+exports.compile = compile;
+exports.defineKey = defineKey;
+
+const _isEmptyOptions = Object.freeze({
+  minimize: true,
+  virtuals: false,
+  getters: false,
+  transform: false
+});
+
+/**
+ * Compiles schemas.
+ * @param {Object} tree
+ * @param {Any} proto
+ * @param {String} prefix
+ * @param {Object} options
+ * @api private
+ */
+
+function compile(tree, proto, prefix, options) {
+  Document = Document || require('../../document');
+  const typeKey = options.typeKey;
+
+  for (const key of Object.keys(tree)) {
+    const limb = tree[key];
+
+    const hasSubprops = isPOJO(limb) &&
+      Object.keys(limb).length > 0 &&
+      (!limb[typeKey] || (typeKey === 'type' && isPOJO(limb.type) && limb.type.type));
+    const subprops = hasSubprops ? limb : null;
+
+    defineKey({ prop: key, subprops: subprops, prototype: proto, prefix: prefix, options: options });
+  }
+}
+
+/**
+ * Defines the accessor named prop on the incoming prototype.
+ * @param {Object} options
+ * @param {String} options.prop
+ * @param {Boolean} options.subprops
+ * @param {Any} options.prototype
+ * @param {String} [options.prefix]
+ * @param {Object} options.options
+ * @api private
+ */
+
+function defineKey({ prop, subprops, prototype, prefix, options }) {
+  Document = Document || require('../../document');
+  const path = (prefix ? prefix + '.' : '') + prop;
+  prefix = prefix || '';
+
+  if (subprops) {
+    Object.defineProperty(prototype, prop, {
+      enumerable: true,
+      configurable: true,
+      get: function() {
+        const _this = this;
+        if (!this.$__.getters) {
+          this.$__.getters = {};
+        }
+
+        if (!this.$__.getters[path]) {
+          const nested = Object.create(Document.prototype, getOwnPropertyDescriptors(this));
+
+          // save scope for nested getters/setters
+          if (!prefix) {
+            nested.$__[scopeSymbol] = this;
+          }
+          nested.$__.nestedPath = path;
+
+          Object.defineProperty(nested, 'schema', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: prototype.schema
+          });
+
+          Object.defineProperty(nested, '$__schema', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: prototype.schema
+          });
+
+          Object.defineProperty(nested, documentSchemaSymbol, {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: prototype.schema
+          });
+
+          Object.defineProperty(nested, 'toObject', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: function() {
+              return clone(_this.get(path, null, {
+                virtuals: this &&
+                  this.schema &&
+                  this.schema.options &&
+                  this.schema.options.toObject &&
+                  this.schema.options.toObject.virtuals || null
+              }));
+            }
+          });
+
+          Object.defineProperty(nested, '$__get', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: function() {
+              return _this.get(path, null, {
+                virtuals: this && this.schema && this.schema.options && this.schema.options.toObject && this.schema.options.toObject.virtuals || null
+              });
+            }
+          });
+
+          Object.defineProperty(nested, 'toJSON', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: function() {
+              return _this.get(path, null, {
+                virtuals: this && this.schema && this.schema.options && this.schema.options.toJSON && this.schema.options.toJSON.virtuals || null
+              });
+            }
+          });
+
+          Object.defineProperty(nested, '$__isNested', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: true
+          });
+
+          Object.defineProperty(nested, '$isEmpty', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: function() {
+              return Object.keys(this.get(path, null, _isEmptyOptions) || {}).length === 0;
+            }
+          });
+
+          Object.defineProperty(nested, '$__parent', {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: this
+          });
+
+          compile(subprops, nested, path, options);
+          this.$__.getters[path] = nested;
+        }
+
+        return this.$__.getters[path];
+      },
+      set: function(v) {
+        if (v != null && v.$__isNested) {
+          // Convert top-level to POJO, but leave subdocs hydrated so `$set`
+          // can handle them. See gh-9293.
+          v = v.$__get();
+        } else if (v instanceof Document && !v.$__isNested) {
+          v = v.$toObject(internalToObjectOptions);
+        }
+        const doc = this.$__[scopeSymbol] || this;
+        doc.$set(path, v);
+      }
+    });
+  } else {
+    Object.defineProperty(prototype, prop, {
+      enumerable: true,
+      configurable: true,
+      get: function() {
+        return this[getSymbol].call(this.$__[scopeSymbol] || this, path);
+      },
+      set: function(v) {
+        this.$set.call(this.$__[scopeSymbol] || this, path, v);
+      }
+    });
+  }
+}
+
+// gets descriptors for all properties of `object`
+// makes all properties non-enumerable to match previous behavior to #2211
+function getOwnPropertyDescriptors(object) {
+  const result = {};
+
+  Object.getOwnPropertyNames(object).forEach(function(key) {
+    const skip = [
+      'isNew',
+      '$__',
+      '$errors',
+      'errors',
+      '_doc',
+      '$locals',
+      '$op',
+      '__parentArray',
+      '__index',
+      '$isDocumentArrayElement'
+    ].indexOf(key) === -1;
+    if (skip) {
+      return;
+    }
+
+    result[key] = Object.getOwnPropertyDescriptor(object, key);
+    result[key].enumerable = false;
+  });
+
+  return result;
+}

node_modules/mongoose/lib/helpers/document/getEmbeddedDiscriminatorPath.js

@@ -0,0 +1,50 @@
+'use strict';
+
+const get = require('../get');
+const getSchemaDiscriminatorByValue = require('../discriminator/getSchemaDiscriminatorByValue');
+
+/**
+ * Like `schema.path()`, except with a document, because impossible to
+ * determine path type without knowing the embedded discriminator key.
+ * @param {Document} doc
+ * @param {String} path
+ * @param {Object} [options]
+ * @api private
+ */
+
+module.exports = function getEmbeddedDiscriminatorPath(doc, path, options) {
+  options = options || {};
+  const typeOnly = options.typeOnly;
+  const parts = path.indexOf('.') === -1 ? [path] : path.split('.');
+  let schemaType = null;
+  let type = 'adhocOrUndefined';
+
+  const schema = getSchemaDiscriminatorByValue(doc.schema, doc.get(doc.schema.options.discriminatorKey)) || doc.schema;
+
+  for (let i = 0; i < parts.length; ++i) {
+    const subpath = parts.slice(0, i + 1).join('.');
+    schemaType = schema.path(subpath);
+    if (schemaType == null) {
+      type = 'adhocOrUndefined';
+      continue;
+    }
+    if (schemaType.instance === 'Mixed') {
+      return typeOnly ? 'real' : schemaType;
+    }
+    type = schema.pathType(subpath);
+    if ((schemaType.$isSingleNested || schemaType.$isMongooseDocumentArrayElement) &&
+    schemaType.schema.discriminators != null) {
+      const discriminators = schemaType.schema.discriminators;
+      const discriminatorKey = doc.get(subpath + '.' +
+        get(schemaType, 'schema.options.discriminatorKey'));
+      if (discriminatorKey == null || discriminators[discriminatorKey] == null) {
+        continue;
+      }
+      const rest = parts.slice(i + 1).join('.');
+      return getEmbeddedDiscriminatorPath(doc.get(subpath), rest, options);
+    }
+  }
+
+  // Are we getting the whole schema or just the type, 'real', 'nested', etc.
+  return typeOnly ? type : schemaType;
+};

node_modules/mongoose/lib/helpers/document/handleSpreadDoc.js

@@ -0,0 +1,35 @@
+'use strict';
+
+const utils = require('../../utils');
+
+const keysToSkip = new Set(['__index', '__parentArray', '_doc']);
+
+/**
+ * Using spread operator on a Mongoose document gives you a
+ * POJO that has a tendency to cause infinite recursion. So
+ * we use this function on `set()` to prevent that.
+ */
+
+module.exports = function handleSpreadDoc(v, includeExtraKeys) {
+  if (utils.isPOJO(v) && v.$__ != null && v._doc != null) {
+    if (includeExtraKeys) {
+      const extraKeys = {};
+      for (const key of Object.keys(v)) {
+        if (typeof key === 'symbol') {
+          continue;
+        }
+        if (key[0] === '$') {
+          continue;
+        }
+        if (keysToSkip.has(key)) {
+          continue;
+        }
+        extraKeys[key] = v[key];
+      }
+      return { ...v._doc, ...extraKeys };
+    }
+    return v._doc;
+  }
+
+  return v;
+};

node_modules/mongoose/lib/helpers/each.js

@@ -0,0 +1,25 @@
+'use strict';
+
+module.exports = function each(arr, cb, done) {
+  if (arr.length === 0) {
+    return done();
+  }
+
+  let remaining = arr.length;
+  let err = null;
+  for (const v of arr) {
+    cb(v, function(_err) {
+      if (err != null) {
+        return;
+      }
+      if (_err != null) {
+        err = _err;
+        return done(err);
+      }
+
+      if (--remaining <= 0) {
+        return done();
+      }
+    });
+  }
+};

node_modules/mongoose/lib/helpers/error/combinePathErrors.js

@@ -0,0 +1,22 @@
+'use strict';
+
+/*!
+ * ignore
+ */
+
+module.exports = function combinePathErrors(err) {
+  const keys = Object.keys(err.errors || {});
+  const len = keys.length;
+  const msgs = [];
+  let key;
+
+  for (let i = 0; i < len; ++i) {
+    key = keys[i];
+    if (err === err.errors[key]) {
+      continue;
+    }
+    msgs.push(key + ': ' + err.errors[key].message);
+  }
+
+  return msgs.join(', ');
+};

node_modules/mongoose/lib/helpers/firstKey.js

@@ -0,0 +1,8 @@
+'use strict';
+
+module.exports = function firstKey(obj) {
+  if (obj == null) {
+    return null;
+  }
+  return Object.keys(obj)[0];
+};

node_modules/mongoose/lib/helpers/get.js

@@ -0,0 +1,65 @@
+'use strict';
+
+/**
+ * Simplified lodash.get to work around the annoying null quirk. See:
+ * https://github.com/lodash/lodash/issues/3659
+ * @api private
+ */
+
+module.exports = function get(obj, path, def) {
+  let parts;
+  let isPathArray = false;
+  if (typeof path === 'string') {
+    if (path.indexOf('.') === -1) {
+      const _v = getProperty(obj, path);
+      if (_v == null) {
+        return def;
+      }
+      return _v;
+    }
+
+    parts = path.split('.');
+  } else {
+    isPathArray = true;
+    parts = path;
+
+    if (parts.length === 1) {
+      const _v = getProperty(obj, parts[0]);
+      if (_v == null) {
+        return def;
+      }
+      return _v;
+    }
+  }
+  let rest = path;
+  let cur = obj;
+  for (const part of parts) {
+    if (cur == null) {
+      return def;
+    }
+
+    // `lib/cast.js` depends on being able to get dotted paths in updates,
+    // like `{ $set: { 'a.b': 42 } }`
+    if (!isPathArray && cur[rest] != null) {
+      return cur[rest];
+    }
+
+    cur = getProperty(cur, part);
+
+    if (!isPathArray) {
+      rest = rest.substr(part.length + 1);
+    }
+  }
+
+  return cur == null ? def : cur;
+};
+
+function getProperty(obj, prop) {
+  if (obj == null) {
+    return obj;
+  }
+  if (obj instanceof Map) {
+    return obj.get(prop);
+  }
+  return obj[prop];
+}

node_modules/mongoose/lib/helpers/getConstructorName.js

@@ -0,0 +1,16 @@
+'use strict';
+
+/**
+ * If `val` is an object, returns constructor name, if possible. Otherwise returns undefined.
+ * @api private
+ */
+
+module.exports = function getConstructorName(val) {
+  if (val == null) {
+    return void 0;
+  }
+  if (typeof val.constructor !== 'function') {
+    return void 0;
+  }
+  return val.constructor.name;
+};

node_modules/mongoose/lib/helpers/getDefaultBulkwriteResult.js

@@ -0,0 +1,27 @@
+'use strict';
+function getDefaultBulkwriteResult() {
+  return {
+    result: {
+      ok: 1,
+      writeErrors: [],
+      writeConcernErrors: [],
+      insertedIds: [],
+      nInserted: 0,
+      nUpserted: 0,
+      nMatched: 0,
+      nModified: 0,
+      nRemoved: 0,
+      upserted: []
+    },
+    insertedCount: 0,
+    matchedCount: 0,
+    modifiedCount: 0,
+    deletedCount: 0,
+    upsertedCount: 0,
+    upsertedIds: {},
+    insertedIds: {},
+    n: 0
+  };
+}
+
+module.exports = getDefaultBulkwriteResult;

node_modules/mongoose/lib/helpers/getFunctionName.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const functionNameRE = /^function\s*([^\s(]+)/;
+
+module.exports = function(fn) {
+  return (
+    fn.name ||
+    (fn.toString().trim().match(functionNameRE) || [])[1]
+  );
+};

node_modules/mongoose/lib/helpers/immediate.js

@@ -0,0 +1,16 @@
+/*!
+ * Centralize this so we can more easily work around issues with people
+ * stubbing out `process.nextTick()` in tests using sinon:
+ * https://github.com/sinonjs/lolex#automatically-incrementing-mocked-time
+ * See gh-6074
+ */
+
+'use strict';
+
+const nextTick = typeof process !== 'undefined' && typeof process.nextTick === 'function' ?
+  process.nextTick.bind(process) :
+  cb => setTimeout(cb, 0); // Fallback for browser build
+
+module.exports = function immediate(cb) {
+  return nextTick(cb);
+};

node_modules/mongoose/lib/helpers/indexes/applySchemaCollation.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const isTextIndex = require('./isTextIndex');
+
+module.exports = function applySchemaCollation(indexKeys, indexOptions, schemaOptions) {
+  if (isTextIndex(indexKeys)) {
+    return;
+  }
+
+  if (schemaOptions.hasOwnProperty('collation') && !indexOptions.hasOwnProperty('collation')) {
+    indexOptions.collation = schemaOptions.collation;
+  }
+};

node_modules/mongoose/lib/helpers/indexes/decorateDiscriminatorIndexOptions.js

@@ -0,0 +1,14 @@
+'use strict';
+
+module.exports = function decorateDiscriminatorIndexOptions(schema, indexOptions) {
+  // If the model is a discriminator and has an index, add a
+  // partialFilterExpression by default so the index will only apply
+  // to that discriminator.
+  const discriminatorName = schema.discriminatorMapping && schema.discriminatorMapping.value;
+  if (discriminatorName && !('sparse' in indexOptions)) {
+    const discriminatorKey = schema.options.discriminatorKey;
+    indexOptions.partialFilterExpression = indexOptions.partialFilterExpression || {};
+    indexOptions.partialFilterExpression[discriminatorKey] = discriminatorName;
+  }
+  return indexOptions;
+};

node_modules/mongoose/lib/helpers/indexes/getRelatedIndexes.js

@@ -0,0 +1,59 @@
+'use strict';
+
+function getRelatedSchemaIndexes(model, schemaIndexes) {
+  return getRelatedIndexes({
+    baseModelName: model.baseModelName,
+    discriminatorMapping: model.schema.discriminatorMapping,
+    indexes: schemaIndexes,
+    indexesType: 'schema'
+  });
+}
+
+function getRelatedDBIndexes(model, dbIndexes) {
+  return getRelatedIndexes({
+    baseModelName: model.baseModelName,
+    discriminatorMapping: model.schema.discriminatorMapping,
+    indexes: dbIndexes,
+    indexesType: 'db'
+  });
+}
+
+module.exports = {
+  getRelatedSchemaIndexes,
+  getRelatedDBIndexes
+};
+
+function getRelatedIndexes({
+  baseModelName,
+  discriminatorMapping,
+  indexes,
+  indexesType
+}) {
+  const discriminatorKey = discriminatorMapping && discriminatorMapping.key;
+  const discriminatorValue = discriminatorMapping && discriminatorMapping.value;
+
+  if (!discriminatorKey) {
+    return indexes;
+  }
+
+  const isChildDiscriminatorModel = Boolean(baseModelName);
+  if (isChildDiscriminatorModel) {
+    return indexes.filter(index => {
+      const partialFilterExpression = getPartialFilterExpression(index, indexesType);
+      return partialFilterExpression && partialFilterExpression[discriminatorKey] === discriminatorValue;
+    });
+  }
+
+  return indexes.filter(index => {
+    const partialFilterExpression = getPartialFilterExpression(index, indexesType);
+    return !partialFilterExpression || !partialFilterExpression[discriminatorKey];
+  });
+}
+
+function getPartialFilterExpression(index, indexesType) {
+  if (indexesType === 'schema') {
+    const options = index[1];
+    return options && options.partialFilterExpression;
+  }
+  return index.partialFilterExpression;
+}

node_modules/mongoose/lib/helpers/indexes/isDefaultIdIndex.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const get = require('../get');
+
+module.exports = function isDefaultIdIndex(index) {
+  if (Array.isArray(index)) {
+    // Mongoose syntax
+    const keys = Object.keys(index[0]);
+    return keys.length === 1 && keys[0] === '_id' && index[0]._id !== 'hashed';
+  }
+
+  if (typeof index !== 'object') {
+    return false;
+  }
+
+  const key = get(index, 'key', {});
+  return Object.keys(key).length === 1 && key.hasOwnProperty('_id');
+};

node_modules/mongoose/lib/helpers/indexes/isIndexEqual.js

@@ -0,0 +1,96 @@
+'use strict';
+
+const get = require('../get');
+const utils = require('../../utils');
+/**
+ * Given a Mongoose index definition (key + options objects) and a MongoDB server
+ * index definition, determine if the two indexes are equal.
+ *
+ * @param {Object} schemaIndexKeysObject the Mongoose index spec
+ * @param {Object} options the Mongoose index definition's options
+ * @param {Object} dbIndex the index in MongoDB as returned by `listIndexes()`
+ * @api private
+ */
+
+module.exports = function isIndexEqual(schemaIndexKeysObject, options, dbIndex) {
+  // Special case: text indexes have a special format in the db. For example,
+  // `{ name: 'text' }` becomes:
+  // {
+  //   v: 2,
+  //   key: { _fts: 'text', _ftsx: 1 },
+  //   name: 'name_text',
+  //   ns: 'test.tests',
+  //   background: true,
+  //   weights: { name: 1 },
+  //   default_language: 'english',
+  //   language_override: 'language',
+  //   textIndexVersion: 3
+  // }
+  if (dbIndex.textIndexVersion != null) {
+    delete dbIndex.key._fts;
+    delete dbIndex.key._ftsx;
+    const weights = { ...dbIndex.weights, ...dbIndex.key };
+    if (Object.keys(weights).length !== Object.keys(schemaIndexKeysObject).length) {
+      return false;
+    }
+    for (const prop of Object.keys(weights)) {
+      if (!(prop in schemaIndexKeysObject)) {
+        return false;
+      }
+      const weight = weights[prop];
+      if (weight !== get(options, 'weights.' + prop) && !(weight === 1 && get(options, 'weights.' + prop) == null)) {
+        return false;
+      }
+    }
+
+    if (options['default_language'] !== dbIndex['default_language']) {
+      return dbIndex['default_language'] === 'english' && options['default_language'] == null;
+    }
+
+    return true;
+  }
+
+  const optionKeys = [
+    'unique',
+    'partialFilterExpression',
+    'sparse',
+    'expireAfterSeconds',
+    'collation'
+  ];
+  for (const key of optionKeys) {
+    if (!(key in options) && !(key in dbIndex)) {
+      continue;
+    }
+    if (key === 'collation') {
+      if (options[key] == null || dbIndex[key] == null) {
+        return options[key] == null && dbIndex[key] == null;
+      }
+      const definedKeys = Object.keys(options.collation);
+      const schemaCollation = options.collation;
+      const dbCollation = dbIndex.collation;
+      for (const opt of definedKeys) {
+        if (get(schemaCollation, opt) !== get(dbCollation, opt)) {
+          return false;
+        }
+      }
+    } else if (!utils.deepEqual(options[key], dbIndex[key])) {
+      return false;
+    }
+  }
+
+  const schemaIndexKeys = Object.keys(schemaIndexKeysObject);
+  const dbIndexKeys = Object.keys(dbIndex.key);
+  if (schemaIndexKeys.length !== dbIndexKeys.length) {
+    return false;
+  }
+  for (let i = 0; i < schemaIndexKeys.length; ++i) {
+    if (schemaIndexKeys[i] !== dbIndexKeys[i]) {
+      return false;
+    }
+    if (!utils.deepEqual(schemaIndexKeysObject[schemaIndexKeys[i]], dbIndex.key[dbIndexKeys[i]])) {
+      return false;
+    }
+  }
+
+  return true;
+};

node_modules/mongoose/lib/helpers/indexes/isTextIndex.js

@@ -0,0 +1,16 @@
+'use strict';
+
+/**
+ * Returns `true` if the given index options have a `text` option.
+ */
+
+module.exports = function isTextIndex(indexKeys) {
+  let isTextIndex = false;
+  for (const key of Object.keys(indexKeys)) {
+    if (indexKeys[key] === 'text') {
+      isTextIndex = true;
+    }
+  }
+
+  return isTextIndex;
+};

node_modules/mongoose/lib/helpers/isAsyncFunction.js

@@ -0,0 +1,9 @@
+'use strict';
+
+module.exports = function isAsyncFunction(v) {
+  return (
+    typeof v === 'function' &&
+    v.constructor &&
+    v.constructor.name === 'AsyncFunction'
+  );
+};

node_modules/mongoose/lib/helpers/isBsonType.js

@@ -0,0 +1,16 @@
+'use strict';
+
+/**
+ * Get the bson type, if it exists
+ * @api private
+ */
+
+function isBsonType(obj, typename) {
+  return (
+    typeof obj === 'object' &&
+    obj !== null &&
+    obj._bsontype === typename
+  );
+}
+
+module.exports = isBsonType;

node_modules/mongoose/lib/helpers/isMongooseObject.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const isMongooseArray = require('../types/array/isMongooseArray').isMongooseArray;
+/**
+ * Returns if `v` is a mongoose object that has a `toObject()` method we can use.
+ *
+ * This is for compatibility with libs like Date.js which do foolish things to Natives.
+ *
+ * @param {Any} v
+ * @api private
+ */
+
+module.exports = function(v) {
+  return (
+    v != null && (
+      isMongooseArray(v) || // Array or Document Array
+      v.$__ != null || // Document
+      v.isMongooseBuffer || // Buffer
+      v.$isMongooseMap // Map
+    )
+  );
+};

node_modules/mongoose/lib/helpers/isObject.js

@@ -0,0 +1,16 @@
+'use strict';
+
+/**
+ * Determines if `arg` is an object.
+ *
+ * @param {Object|Array|String|Function|RegExp|any} arg
+ * @api private
+ * @return {Boolean}
+ */
+
+module.exports = function(arg) {
+  return (
+    Buffer.isBuffer(arg) ||
+    Object.prototype.toString.call(arg) === '[object Object]'
+  );
+};

node_modules/mongoose/lib/helpers/isPOJO.js

@@ -0,0 +1,12 @@
+'use strict';
+
+module.exports = function isPOJO(arg) {
+  if (arg == null || typeof arg !== 'object') {
+    return false;
+  }
+  const proto = Object.getPrototypeOf(arg);
+  // Prototype may be null if you used `Object.create(null)`
+  // Checking `proto`'s constructor is safe because `getPrototypeOf()`
+  // explicitly crosses the boundary from object data to object metadata
+  return !proto || proto.constructor.name === 'Object';
+};

node_modules/mongoose/lib/helpers/isPromise.js

@@ -0,0 +1,6 @@
+'use strict';
+function isPromise(val) {
+  return !!val && (typeof val === 'object' || typeof val === 'function') && typeof val.then === 'function';
+}
+
+module.exports = isPromise;

node_modules/mongoose/lib/helpers/isSimpleValidator.js

@@ -0,0 +1,22 @@
+'use strict';
+
+/**
+ * Determines if `arg` is a flat object.
+ *
+ * @param {Object|Array|String|Function|RegExp|any} arg
+ * @api private
+ * @return {Boolean}
+ */
+
+module.exports = function isSimpleValidator(obj) {
+  const keys = Object.keys(obj);
+  let result = true;
+  for (let i = 0, len = keys.length; i < len; ++i) {
+    if (typeof obj[keys[i]] === 'object' && obj[keys[i]] !== null) {
+      result = false;
+      break;
+    }
+  }
+
+  return result;
+};

node_modules/mongoose/lib/helpers/model/applyDefaultsToPOJO.js

@@ -0,0 +1,52 @@
+'use strict';
+
+module.exports = function applyDefaultsToPOJO(doc, schema) {
+  const paths = Object.keys(schema.paths);
+  const plen = paths.length;
+
+  for (let i = 0; i < plen; ++i) {
+    let curPath = '';
+    const p = paths[i];
+
+    const type = schema.paths[p];
+    const path = type.splitPath();
+    const len = path.length;
+    let doc_ = doc;
+    for (let j = 0; j < len; ++j) {
+      if (doc_ == null) {
+        break;
+      }
+
+      const piece = path[j];
+      curPath += (!curPath.length ? '' : '.') + piece;
+
+      if (j === len - 1) {
+        if (typeof doc_[piece] !== 'undefined') {
+          if (type.$isSingleNested) {
+            applyDefaultsToPOJO(doc_[piece], type.caster.schema);
+          } else if (type.$isMongooseDocumentArray && Array.isArray(doc_[piece])) {
+            doc_[piece].forEach(el => applyDefaultsToPOJO(el, type.schema));
+          }
+
+          break;
+        }
+
+        const def = type.getDefault(doc, false, { skipCast: true });
+        if (typeof def !== 'undefined') {
+          doc_[piece] = def;
+
+          if (type.$isSingleNested) {
+            applyDefaultsToPOJO(def, type.caster.schema);
+          } else if (type.$isMongooseDocumentArray && Array.isArray(def)) {
+            def.forEach(el => applyDefaultsToPOJO(el, type.schema));
+          }
+        }
+      } else {
+        if (doc_[piece] == null) {
+          doc_[piece] = {};
+        }
+        doc_ = doc_[piece];
+      }
+    }
+  }
+};

node_modules/mongoose/lib/helpers/model/applyHooks.js

@@ -0,0 +1,149 @@
+'use strict';
+
+const symbols = require('../../schema/symbols');
+const promiseOrCallback = require('../promiseOrCallback');
+
+/*!
+ * ignore
+ */
+
+module.exports = applyHooks;
+
+/*!
+ * ignore
+ */
+
+applyHooks.middlewareFunctions = [
+  'deleteOne',
+  'save',
+  'validate',
+  'remove',
+  'updateOne',
+  'init'
+];
+
+/*!
+ * ignore
+ */
+
+const alreadyHookedFunctions = new Set(applyHooks.middlewareFunctions.flatMap(fn => ([fn, `$__${fn}`])));
+
+/**
+ * Register hooks for this model
+ *
+ * @param {Model} model
+ * @param {Schema} schema
+ * @param {Object} options
+ * @api private
+ */
+
+function applyHooks(model, schema, options) {
+  options = options || {};
+
+  const kareemOptions = {
+    useErrorHandlers: true,
+    numCallbackParams: 1,
+    nullResultByDefault: true,
+    contextParameter: true
+  };
+  const objToDecorate = options.decorateDoc ? model : model.prototype;
+
+  model.$appliedHooks = true;
+  for (const key of Object.keys(schema.paths)) {
+    const type = schema.paths[key];
+    let childModel = null;
+    if (type.$isSingleNested) {
+      childModel = type.caster;
+    } else if (type.$isMongooseDocumentArray) {
+      childModel = type.Constructor;
+    } else {
+      continue;
+    }
+
+    if (childModel.$appliedHooks) {
+      continue;
+    }
+
+    applyHooks(childModel, type.schema, options);
+    if (childModel.discriminators != null) {
+      const keys = Object.keys(childModel.discriminators);
+      for (const key of keys) {
+        applyHooks(childModel.discriminators[key],
+          childModel.discriminators[key].schema, options);
+      }
+    }
+  }
+
+  // Built-in hooks rely on hooking internal functions in order to support
+  // promises and make it so that `doc.save.toString()` provides meaningful
+  // information.
+
+  const middleware = schema.s.hooks.
+    filter(hook => {
+      if (hook.name === 'updateOne' || hook.name === 'deleteOne') {
+        return !!hook['document'];
+      }
+      if (hook.name === 'remove' || hook.name === 'init') {
+        return hook['document'] == null || !!hook['document'];
+      }
+      if (hook.query != null || hook.document != null) {
+        return hook.document !== false;
+      }
+      return true;
+    }).
+    filter(hook => {
+      // If user has overwritten the method, don't apply built-in middleware
+      if (schema.methods[hook.name]) {
+        return !hook.fn[symbols.builtInMiddleware];
+      }
+
+      return true;
+    });
+
+  model._middleware = middleware;
+
+  objToDecorate.$__originalValidate = objToDecorate.$__originalValidate || objToDecorate.$__validate;
+
+  for (const method of ['save', 'validate', 'remove', 'deleteOne']) {
+    const toWrap = method === 'validate' ? '$__originalValidate' : `$__${method}`;
+    const wrapped = middleware.
+      createWrapper(method, objToDecorate[toWrap], null, kareemOptions);
+    objToDecorate[`$__${method}`] = wrapped;
+  }
+  objToDecorate.$__init = middleware.
+    createWrapperSync('init', objToDecorate.$__init, null, kareemOptions);
+
+  // Support hooks for custom methods
+  const customMethods = Object.keys(schema.methods);
+  const customMethodOptions = Object.assign({}, kareemOptions, {
+    // Only use `checkForPromise` for custom methods, because mongoose
+    // query thunks are not as consistent as I would like about returning
+    // a nullish value rather than the query. If a query thunk returns
+    // a query, `checkForPromise` causes infinite recursion
+    checkForPromise: true
+  });
+  for (const method of customMethods) {
+    if (alreadyHookedFunctions.has(method)) {
+      continue;
+    }
+    if (!middleware.hasHooks(method)) {
+      // Don't wrap if there are no hooks for the custom method to avoid
+      // surprises. Also, `createWrapper()` enforces consistent async,
+      // so wrapping a sync method would break it.
+      continue;
+    }
+    const originalMethod = objToDecorate[method];
+    objToDecorate[method] = function() {
+      const args = Array.prototype.slice.call(arguments);
+      const cb = args.slice(-1).pop();
+      const argsWithoutCallback = typeof cb === 'function' ?
+        args.slice(0, args.length - 1) : args;
+      return promiseOrCallback(cb, callback => {
+        return this[`$__${method}`].apply(this,
+          argsWithoutCallback.concat([callback]));
+      }, model.events);
+    };
+    objToDecorate[`$__${method}`] = middleware.
+      createWrapper(method, originalMethod, null, customMethodOptions);
+  }
+}

node_modules/mongoose/lib/helpers/model/applyMethods.js

@@ -0,0 +1,70 @@
+'use strict';
+
+const get = require('../get');
+const utils = require('../../utils');
+
+/**
+ * Register methods for this model
+ *
+ * @param {Model} model
+ * @param {Schema} schema
+ * @api private
+ */
+
+module.exports = function applyMethods(model, schema) {
+  const Model = require('../../model');
+
+  function apply(method, schema) {
+    Object.defineProperty(model.prototype, method, {
+      get: function() {
+        const h = {};
+        for (const k in schema.methods[method]) {
+          h[k] = schema.methods[method][k].bind(this);
+        }
+        return h;
+      },
+      configurable: true
+    });
+  }
+  for (const method of Object.keys(schema.methods)) {
+    const fn = schema.methods[method];
+    if (schema.tree.hasOwnProperty(method)) {
+      throw new Error('You have a method and a property in your schema both ' +
+        'named "' + method + '"');
+    }
+
+    // Avoid making custom methods if user sets a method to itself, e.g.
+    // `schema.method(save, Document.prototype.save)`. Can happen when
+    // calling `loadClass()` with a class that `extends Document`. See gh-12254
+    if (typeof fn === 'function' &&
+        Model.prototype[method] === fn) {
+      delete schema.methods[method];
+      continue;
+    }
+
+    if (schema.reserved[method] &&
+        !get(schema, `methodOptions.${method}.suppressWarning`, false)) {
+      utils.warn(`mongoose: the method name "${method}" is used by mongoose ` +
+        'internally, overwriting it may cause bugs. If you\'re sure you know ' +
+        'what you\'re doing, you can suppress this error by using ' +
+        `\`schema.method('${method}', fn, { suppressWarning: true })\`.`);
+    }
+    if (typeof fn === 'function') {
+      model.prototype[method] = fn;
+    } else {
+      apply(method, schema);
+    }
+  }
+
+  // Recursively call `applyMethods()` on child schemas
+  model.$appliedMethods = true;
+  for (const key of Object.keys(schema.paths)) {
+    const type = schema.paths[key];
+    if (type.$isSingleNested && !type.caster.$appliedMethods) {
+      applyMethods(type.caster, type.schema);
+    }
+    if (type.$isMongooseDocumentArray && !type.Constructor.$appliedMethods) {
+      applyMethods(type.Constructor, type.schema);
+    }
+  }
+};

node_modules/mongoose/lib/helpers/model/applyStaticHooks.js

@@ -0,0 +1,71 @@
+'use strict';
+
+const middlewareFunctions = require('../query/applyQueryMiddleware').middlewareFunctions;
+const promiseOrCallback = require('../promiseOrCallback');
+
+module.exports = function applyStaticHooks(model, hooks, statics) {
+  const kareemOptions = {
+    useErrorHandlers: true,
+    numCallbackParams: 1
+  };
+
+  hooks = hooks.filter(hook => {
+    // If the custom static overwrites an existing query middleware, don't apply
+    // middleware to it by default. This avoids a potential backwards breaking
+    // change with plugins like `mongoose-delete` that use statics to overwrite
+    // built-in Mongoose functions.
+    if (middlewareFunctions.indexOf(hook.name) !== -1) {
+      return !!hook.model;
+    }
+    return hook.model !== false;
+  });
+
+  model.$__insertMany = hooks.createWrapper('insertMany',
+    model.$__insertMany, model, kareemOptions);
+
+  for (const key of Object.keys(statics)) {
+    if (hooks.hasHooks(key)) {
+      const original = model[key];
+
+      model[key] = function() {
+        const numArgs = arguments.length;
+        const lastArg = numArgs > 0 ? arguments[numArgs - 1] : null;
+        const cb = typeof lastArg === 'function' ? lastArg : null;
+        const args = Array.prototype.slice.
+          call(arguments, 0, cb == null ? numArgs : numArgs - 1);
+        // Special case: can't use `Kareem#wrap()` because it doesn't currently
+        // support wrapped functions that return a promise.
+        return promiseOrCallback(cb, callback => {
+          hooks.execPre(key, model, args, function(err) {
+            if (err != null) {
+              return callback(err);
+            }
+
+            let postCalled = 0;
+            const ret = original.apply(model, args.concat(post));
+            if (ret != null && typeof ret.then === 'function') {
+              ret.then(res => post(null, res), err => post(err));
+            }
+
+            function post(error, res) {
+              if (postCalled++ > 0) {
+                return;
+              }
+
+              if (error != null) {
+                return callback(error);
+              }
+
+              hooks.execPost(key, model, [res], function(error) {
+                if (error != null) {
+                  return callback(error);
+                }
+                callback(null, res);
+              });
+            }
+          });
+        }, model.events);
+      };
+    }
+  }
+};

node_modules/mongoose/lib/helpers/model/applyStatics.js

@@ -0,0 +1,13 @@
+'use strict';
+
+/**
+ * Register statics for this model
+ * @param {Model} model
+ * @param {Schema} schema
+ * @api private
+ */
+module.exports = function applyStatics(model, schema) {
+  for (const i in schema.statics) {
+    model[i] = schema.statics[i];
+  }
+};

node_modules/mongoose/lib/helpers/model/castBulkWrite.js

@@ -0,0 +1,240 @@
+'use strict';
+
+const getDiscriminatorByValue = require('../../helpers/discriminator/getDiscriminatorByValue');
+const applyTimestampsToChildren = require('../update/applyTimestampsToChildren');
+const applyTimestampsToUpdate = require('../update/applyTimestampsToUpdate');
+const cast = require('../../cast');
+const castUpdate = require('../query/castUpdate');
+const setDefaultsOnInsert = require('../setDefaultsOnInsert');
+
+/**
+ * Given a model and a bulkWrite op, return a thunk that handles casting and
+ * validating the individual op.
+ * @param {Model} originalModel
+ * @param {Object} op
+ * @param {Object} [options]
+ * @api private
+ */
+
+module.exports = function castBulkWrite(originalModel, op, options) {
+  const now = originalModel.base.now();
+
+  if (op['insertOne']) {
+    return (callback) => {
+      const model = decideModelByObject(originalModel, op['insertOne']['document']);
+
+      const doc = new model(op['insertOne']['document']);
+      if (model.schema.options.timestamps && options.timestamps !== false) {
+        doc.initializeTimestamps();
+      }
+      if (options.session != null) {
+        doc.$session(options.session);
+      }
+      op['insertOne']['document'] = doc;
+
+      if (options.skipValidation || op['insertOne'].skipValidation) {
+        callback(null);
+        return;
+      }
+
+      op['insertOne']['document'].$validate().then(
+        () => { callback(null); },
+        err => { callback(err, null); }
+      );
+    };
+  } else if (op['updateOne']) {
+    return (callback) => {
+      try {
+        if (!op['updateOne']['filter']) {
+          throw new Error('Must provide a filter object.');
+        }
+        if (!op['updateOne']['update']) {
+          throw new Error('Must provide an update object.');
+        }
+
+        const model = decideModelByObject(originalModel, op['updateOne']['filter']);
+        const schema = model.schema;
+        const strict = options.strict != null ? options.strict : model.schema.options.strict;
+
+        _addDiscriminatorToObject(schema, op['updateOne']['filter']);
+
+        if (model.schema.$timestamps != null && op['updateOne'].timestamps !== false) {
+          const createdAt = model.schema.$timestamps.createdAt;
+          const updatedAt = model.schema.$timestamps.updatedAt;
+          applyTimestampsToUpdate(now, createdAt, updatedAt, op['updateOne']['update'], {});
+        }
+
+        applyTimestampsToChildren(now, op['updateOne']['update'], model.schema);
+
+        if (op['updateOne'].setDefaultsOnInsert !== false) {
+          setDefaultsOnInsert(op['updateOne']['filter'], model.schema, op['updateOne']['update'], {
+            setDefaultsOnInsert: true,
+            upsert: op['updateOne'].upsert
+          });
+        }
+
+        op['updateOne']['filter'] = cast(model.schema, op['updateOne']['filter'], {
+          strict: strict,
+          upsert: op['updateOne'].upsert
+        });
+
+        op['updateOne']['update'] = castUpdate(model.schema, op['updateOne']['update'], {
+          strict: strict,
+          overwrite: false,
+          upsert: op['updateOne'].upsert
+        }, model, op['updateOne']['filter']);
+      } catch (error) {
+        return callback(error, null);
+      }
+
+      callback(null);
+    };
+  } else if (op['updateMany']) {
+    return (callback) => {
+      try {
+        if (!op['updateMany']['filter']) {
+          throw new Error('Must provide a filter object.');
+        }
+        if (!op['updateMany']['update']) {
+          throw new Error('Must provide an update object.');
+        }
+
+        const model = decideModelByObject(originalModel, op['updateMany']['filter']);
+        const schema = model.schema;
+        const strict = options.strict != null ? options.strict : model.schema.options.strict;
+
+        if (op['updateMany'].setDefaultsOnInsert !== false) {
+          setDefaultsOnInsert(op['updateMany']['filter'], model.schema, op['updateMany']['update'], {
+            setDefaultsOnInsert: true,
+            upsert: op['updateMany'].upsert
+          });
+        }
+
+        if (model.schema.$timestamps != null && op['updateMany'].timestamps !== false) {
+          const createdAt = model.schema.$timestamps.createdAt;
+          const updatedAt = model.schema.$timestamps.updatedAt;
+          applyTimestampsToUpdate(now, createdAt, updatedAt, op['updateMany']['update'], {});
+        }
+
+        applyTimestampsToChildren(now, op['updateMany']['update'], model.schema);
+
+        _addDiscriminatorToObject(schema, op['updateMany']['filter']);
+
+        op['updateMany']['filter'] = cast(model.schema, op['updateMany']['filter'], {
+          strict: strict,
+          upsert: op['updateMany'].upsert
+        });
+
+        op['updateMany']['update'] = castUpdate(model.schema, op['updateMany']['update'], {
+          strict: strict,
+          overwrite: false,
+          upsert: op['updateMany'].upsert
+        }, model, op['updateMany']['filter']);
+      } catch (error) {
+        return callback(error, null);
+      }
+
+      callback(null);
+    };
+  } else if (op['replaceOne']) {
+    return (callback) => {
+      const model = decideModelByObject(originalModel, op['replaceOne']['filter']);
+      const schema = model.schema;
+      const strict = options.strict != null ? options.strict : model.schema.options.strict;
+
+      _addDiscriminatorToObject(schema, op['replaceOne']['filter']);
+      try {
+        op['replaceOne']['filter'] = cast(model.schema, op['replaceOne']['filter'], {
+          strict: strict,
+          upsert: op['replaceOne'].upsert
+        });
+      } catch (error) {
+        return callback(error, null);
+      }
+
+      // set `skipId`, otherwise we get "_id field cannot be changed"
+      const doc = new model(op['replaceOne']['replacement'], strict, true);
+      if (model.schema.options.timestamps) {
+        doc.initializeTimestamps();
+      }
+      if (options.session != null) {
+        doc.$session(options.session);
+      }
+      op['replaceOne']['replacement'] = doc;
+
+      if (options.skipValidation || op['replaceOne'].skipValidation) {
+        op['replaceOne']['replacement'] = op['replaceOne']['replacement'].toBSON();
+        callback(null);
+        return;
+      }
+
+      op['replaceOne']['replacement'].$validate().then(
+        () => {
+          op['replaceOne']['replacement'] = op['replaceOne']['replacement'].toBSON();
+          callback(null);
+        },
+        error => {
+          callback(error, null);
+        }
+      );
+    };
+  } else if (op['deleteOne']) {
+    return (callback) => {
+      const model = decideModelByObject(originalModel, op['deleteOne']['filter']);
+      const schema = model.schema;
+
+      _addDiscriminatorToObject(schema, op['deleteOne']['filter']);
+
+      try {
+        op['deleteOne']['filter'] = cast(model.schema,
+          op['deleteOne']['filter']);
+      } catch (error) {
+        return callback(error, null);
+      }
+
+      callback(null);
+    };
+  } else if (op['deleteMany']) {
+    return (callback) => {
+      const model = decideModelByObject(originalModel, op['deleteMany']['filter']);
+      const schema = model.schema;
+
+      _addDiscriminatorToObject(schema, op['deleteMany']['filter']);
+
+      try {
+        op['deleteMany']['filter'] = cast(model.schema,
+          op['deleteMany']['filter']);
+      } catch (error) {
+        return callback(error, null);
+      }
+
+      callback(null);
+    };
+  } else {
+    return (callback) => {
+      callback(new Error('Invalid op passed to `bulkWrite()`'), null);
+    };
+  }
+};
+
+function _addDiscriminatorToObject(schema, obj) {
+  if (schema == null) {
+    return;
+  }
+  if (schema.discriminatorMapping && !schema.discriminatorMapping.isRoot) {
+    obj[schema.discriminatorMapping.key] = schema.discriminatorMapping.value;
+  }
+}
+
+/**
+ * gets discriminator model if discriminator key is present in object
+ * @api private
+ */
+
+function decideModelByObject(model, object) {
+  const discriminatorKey = model.schema.options.discriminatorKey;
+  if (object != null && object.hasOwnProperty(discriminatorKey)) {
+    model = getDiscriminatorByValue(model.discriminators, object[discriminatorKey]) || model;
+  }
+  return model;
+}

node_modules/mongoose/lib/helpers/model/discriminator.js

@@ -0,0 +1,213 @@
+'use strict';
+
+const Mixed = require('../../schema/mixed');
+const applyBuiltinPlugins = require('../schema/applyBuiltinPlugins');
+const clone = require('../clone');
+const defineKey = require('../document/compile').defineKey;
+const get = require('../get');
+const utils = require('../../utils');
+const mergeDiscriminatorSchema = require('../../helpers/discriminator/mergeDiscriminatorSchema');
+
+const CUSTOMIZABLE_DISCRIMINATOR_OPTIONS = {
+  toJSON: true,
+  toObject: true,
+  _id: true,
+  id: true,
+  virtuals: true,
+  methods: true
+};
+
+/*!
+ * ignore
+ */
+
+module.exports = function discriminator(model, name, schema, tiedValue, applyPlugins, mergeHooks) {
+  if (!(schema && schema.instanceOfSchema)) {
+    throw new Error('You must pass a valid discriminator Schema');
+  }
+
+  mergeHooks = mergeHooks == null ? true : mergeHooks;
+
+  if (model.schema.discriminatorMapping &&
+      !model.schema.discriminatorMapping.isRoot) {
+    throw new Error('Discriminator "' + name +
+        '" can only be a discriminator of the root model');
+  }
+
+  if (applyPlugins) {
+    const applyPluginsToDiscriminators = get(model.base,
+      'options.applyPluginsToDiscriminators', false) || !mergeHooks;
+    // Even if `applyPluginsToDiscriminators` isn't set, we should still apply
+    // global plugins to schemas embedded in the discriminator schema (gh-7370)
+    model.base._applyPlugins(schema, {
+      skipTopLevel: !applyPluginsToDiscriminators
+    });
+  } else if (!mergeHooks) {
+    applyBuiltinPlugins(schema);
+  }
+
+  const key = model.schema.options.discriminatorKey;
+
+  const existingPath = model.schema.path(key);
+  if (existingPath != null) {
+    if (!utils.hasUserDefinedProperty(existingPath.options, 'select')) {
+      existingPath.options.select = true;
+    }
+    existingPath.options.$skipDiscriminatorCheck = true;
+  } else {
+    const baseSchemaAddition = {};
+    baseSchemaAddition[key] = {
+      default: void 0,
+      select: true,
+      $skipDiscriminatorCheck: true
+    };
+    baseSchemaAddition[key][model.schema.options.typeKey] = String;
+    model.schema.add(baseSchemaAddition);
+    defineKey({
+      prop: key,
+      prototype: model.prototype,
+      options: model.schema.options
+    });
+  }
+
+  if (schema.path(key) && schema.path(key).options.$skipDiscriminatorCheck !== true) {
+    throw new Error('Discriminator "' + name +
+        '" cannot have field with name "' + key + '"');
+  }
+
+  let value = name;
+  if ((typeof tiedValue === 'string' && tiedValue.length) || tiedValue != null) {
+    value = tiedValue;
+  }
+
+  function merge(schema, baseSchema) {
+    // Retain original schema before merging base schema
+    schema._baseSchema = baseSchema;
+    if (baseSchema.paths._id &&
+        baseSchema.paths._id.options &&
+        !baseSchema.paths._id.options.auto) {
+      schema.remove('_id');
+    }
+
+    // Find conflicting paths: if something is a path in the base schema
+    // and a nested path in the child schema, overwrite the base schema path.
+    // See gh-6076
+    const baseSchemaPaths = Object.keys(baseSchema.paths);
+    const conflictingPaths = [];
+
+    for (const path of baseSchemaPaths) {
+      if (schema.nested[path]) {
+        conflictingPaths.push(path);
+        continue;
+      }
+
+      if (path.indexOf('.') === -1) {
+        continue;
+      }
+      const sp = path.split('.').slice(0, -1);
+      let cur = '';
+      for (const piece of sp) {
+        cur += (cur.length ? '.' : '') + piece;
+        if (schema.paths[cur] instanceof Mixed ||
+            schema.singleNestedPaths[cur] instanceof Mixed) {
+          conflictingPaths.push(path);
+        }
+      }
+    }
+
+    mergeDiscriminatorSchema(schema, baseSchema);
+
+    // Clean up conflicting paths _after_ merging re: gh-6076
+    for (const conflictingPath of conflictingPaths) {
+      delete schema.paths[conflictingPath];
+    }
+
+    // Rebuild schema models because schemas may have been merged re: #7884
+    schema.childSchemas.forEach(obj => {
+      obj.model.prototype.$__setSchema(obj.schema);
+    });
+
+    const obj = {};
+    obj[key] = {
+      default: value,
+      select: true,
+      set: function(newName) {
+        if (newName === value || (Array.isArray(value) && utils.deepEqual(newName, value))) {
+          return value;
+        }
+        throw new Error('Can\'t set discriminator key "' + key + '"');
+      },
+      $skipDiscriminatorCheck: true
+    };
+    obj[key][schema.options.typeKey] = existingPath ? existingPath.options[schema.options.typeKey] : String;
+    schema.add(obj);
+
+    schema.discriminatorMapping = { key: key, value: value, isRoot: false };
+
+    if (baseSchema.options.collection) {
+      schema.options.collection = baseSchema.options.collection;
+    }
+    const toJSON = schema.options.toJSON;
+    const toObject = schema.options.toObject;
+    const _id = schema.options._id;
+    const id = schema.options.id;
+
+    const keys = Object.keys(schema.options);
+    schema.options.discriminatorKey = baseSchema.options.discriminatorKey;
+    const userProvidedOptions = schema._userProvidedOptions;
+    for (const _key of keys) {
+      if (!CUSTOMIZABLE_DISCRIMINATOR_OPTIONS[_key]) {
+        // Use `schema.options` in `deepEqual()` because of `discriminatorKey`
+        // set above. We don't allow customizing discriminator key, always
+        // overwrite. See gh-9238
+        if (_key in userProvidedOptions && !utils.deepEqual(schema.options[_key], baseSchema.options[_key])) {
+          throw new Error('Can\'t customize discriminator option ' + _key +
+            ' (can only modify ' +
+            Object.keys(CUSTOMIZABLE_DISCRIMINATOR_OPTIONS).join(', ') +
+            ')');
+        }
+      }
+    }
+    schema.options = clone(baseSchema.options);
+
+    for (const _key of Object.keys(userProvidedOptions)) {
+      schema.options[_key] = userProvidedOptions[_key];
+    }
+    if (toJSON) schema.options.toJSON = toJSON;
+    if (toObject) schema.options.toObject = toObject;
+    if (typeof _id !== 'undefined') {
+      schema.options._id = _id;
+    }
+    schema.options.id = id;
+    if (mergeHooks) {
+      schema.s.hooks = model.schema.s.hooks.merge(schema.s.hooks);
+    }
+    if (applyPlugins) {
+      schema.plugins = Array.prototype.slice.call(baseSchema.plugins);
+    }
+    schema.callQueue = baseSchema.callQueue.concat(schema.callQueue);
+    delete schema._requiredpaths; // reset just in case Schema#requiredPaths() was called on either schema
+  }
+
+  // merges base schema into new discriminator schema and sets new type field.
+  merge(schema, model.schema);
+
+  if (!model.discriminators) {
+    model.discriminators = {};
+  }
+
+  if (!model.schema.discriminatorMapping) {
+    model.schema.discriminatorMapping = { key: key, value: null, isRoot: true };
+  }
+  if (!model.schema.discriminators) {
+    model.schema.discriminators = {};
+  }
+
+  model.schema.discriminators[name] = schema;
+
+  if (model.discriminators[name] && !schema.options.overwriteModels) {
+    throw new Error('Discriminator with name "' + name + '" already exists');
+  }
+
+  return schema;
+};

node_modules/mongoose/lib/helpers/model/pushNestedArrayPaths.js

@@ -0,0 +1,15 @@
+'use strict';
+
+module.exports = function pushNestedArrayPaths(paths, nestedArray, path) {
+  if (nestedArray == null) {
+    return;
+  }
+
+  for (let i = 0; i < nestedArray.length; ++i) {
+    if (Array.isArray(nestedArray[i])) {
+      pushNestedArrayPaths(paths, nestedArray[i], path + '.' + i);
+    } else {
+      paths.push(path + '.' + i);
+    }
+  }
+};

node_modules/mongoose/lib/helpers/once.js

@@ -0,0 +1,12 @@
+'use strict';
+
+module.exports = function once(fn) {
+  let called = false;
+  return function() {
+    if (called) {
+      return;
+    }
+    called = true;
+    return fn.apply(null, arguments);
+  };
+};

node_modules/mongoose/lib/helpers/parallelLimit.js

@@ -0,0 +1,55 @@
+'use strict';
+
+module.exports = parallelLimit;
+
+/*!
+ * ignore
+ */
+
+function parallelLimit(fns, limit, callback) {
+  let numInProgress = 0;
+  let numFinished = 0;
+  let error = null;
+
+  if (limit <= 0) {
+    throw new Error('Limit must be positive');
+  }
+
+  if (fns.length === 0) {
+    return callback(null, []);
+  }
+
+  for (let i = 0; i < fns.length && i < limit; ++i) {
+    _start();
+  }
+
+  function _start() {
+    fns[numFinished + numInProgress](_done(numFinished + numInProgress));
+    ++numInProgress;
+  }
+
+  const results = [];
+
+  function _done(index) {
+    return (err, res) => {
+      --numInProgress;
+      ++numFinished;
+
+      if (error != null) {
+        return;
+      }
+      if (err != null) {
+        error = err;
+        return callback(error);
+      }
+
+      results[index] = res;
+
+      if (numFinished === fns.length) {
+        return callback(null, results);
+      } else if (numFinished + numInProgress < fns.length) {
+        _start();
+      }
+    };
+  }
+}

node_modules/mongoose/lib/helpers/path/flattenObjectWithDottedPaths.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const MongooseError = require('../../error/mongooseError');
+const isMongooseObject = require('../isMongooseObject');
+const setDottedPath = require('../path/setDottedPath');
+const util = require('util');
+
+/**
+ * Given an object that may contain dotted paths, flatten the paths out.
+ * For example: `flattenObjectWithDottedPaths({ a: { 'b.c': 42 } })` => `{ a: { b: { c: 42 } } }`
+ */
+
+module.exports = function flattenObjectWithDottedPaths(obj) {
+  if (obj == null || typeof obj !== 'object' || Array.isArray(obj)) {
+    return;
+  }
+  // Avoid Mongoose docs, like docs and maps, because these may cause infinite recursion
+  if (isMongooseObject(obj)) {
+    return;
+  }
+  const keys = Object.keys(obj);
+  for (const key of keys) {
+    const val = obj[key];
+    if (key.indexOf('.') !== -1) {
+      try {
+        delete obj[key];
+        setDottedPath(obj, key, val);
+      } catch (err) {
+        if (!(err instanceof TypeError)) {
+          throw err;
+        }
+        throw new MongooseError(`Conflicting dotted paths when setting document path, key: "${key}", value: ${util.inspect(val)}`);
+      }
+      continue;
+    }
+
+    flattenObjectWithDottedPaths(obj[key]);
+  }
+};

node_modules/mongoose/lib/helpers/path/parentPaths.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const dotRE = /\./g;
+module.exports = function parentPaths(path) {
+  if (path.indexOf('.') === -1) {
+    return [path];
+  }
+  const pieces = path.split(dotRE);
+  const len = pieces.length;
+  const ret = new Array(len);
+  let cur = '';
+  for (let i = 0; i < len; ++i) {
+    cur += (cur.length !== 0) ? '.' + pieces[i] : pieces[i];
+    ret[i] = cur;
+  }
+
+  return ret;
+};

node_modules/mongoose/lib/helpers/path/setDottedPath.js

@@ -0,0 +1,33 @@
+'use strict';
+
+const specialProperties = require('../specialProperties');
+
+
+module.exports = function setDottedPath(obj, path, val) {
+  if (path.indexOf('.') === -1) {
+    if (specialProperties.has(path)) {
+      return;
+    }
+
+    obj[path] = val;
+    return;
+  }
+  const parts = path.split('.');
+
+  const last = parts.pop();
+  let cur = obj;
+  for (const part of parts) {
+    if (specialProperties.has(part)) {
+      continue;
+    }
+    if (cur[part] == null) {
+      cur[part] = {};
+    }
+
+    cur = cur[part];
+  }
+
+  if (!specialProperties.has(last)) {
+    cur[last] = val;
+  }
+};