some progress

node_modules/mongoose/lib/plugins/sharding.js

@@ -0,0 +1,83 @@
+'use strict';
+
+const objectIdSymbol = require('../helpers/symbols').objectIdSymbol;
+const utils = require('../utils');
+
+/*!
+ * ignore
+ */
+
+module.exports = function shardingPlugin(schema) {
+  schema.post('init', function shardingPluginPostInit() {
+    storeShard.call(this);
+    return this;
+  });
+  schema.pre('save', function shardingPluginPreSave(next) {
+    applyWhere.call(this);
+    next();
+  });
+  schema.pre('remove', function shardingPluginPreRemove(next) {
+    applyWhere.call(this);
+    next();
+  });
+  schema.post('save', function shardingPluginPostSave() {
+    storeShard.call(this);
+  });
+};
+
+/*!
+ * ignore
+ */
+
+function applyWhere() {
+  let paths;
+  let len;
+
+  if (this.$__.shardval) {
+    paths = Object.keys(this.$__.shardval);
+    len = paths.length;
+
+    this.$where = this.$where || {};
+    for (let i = 0; i < len; ++i) {
+      this.$where[paths[i]] = this.$__.shardval[paths[i]];
+    }
+  }
+}
+
+/*!
+ * ignore
+ */
+
+module.exports.storeShard = storeShard;
+
+/*!
+ * ignore
+ */
+
+function storeShard() {
+  // backwards compat
+  const key = this.$__schema.options.shardKey || this.$__schema.options.shardkey;
+  if (!utils.isPOJO(key)) {
+    return;
+  }
+
+  const orig = this.$__.shardval = {};
+  const paths = Object.keys(key);
+  const len = paths.length;
+  let val;
+
+  for (let i = 0; i < len; ++i) {
+    val = this.$__getValue(paths[i]);
+    if (val == null) {
+      orig[paths[i]] = val;
+    } else if (utils.isMongooseObject(val)) {
+      orig[paths[i]] = val.toObject({ depopulate: true, _isNested: true });
+    } else if (val instanceof Date || val[objectIdSymbol]) {
+      orig[paths[i]] = val;
+    } else if (typeof val.valueOf === 'function') {
+      orig[paths[i]] = val.valueOf();
+    } else {
+      orig[paths[i]] = val;
+    }
+  }
+}