some progress

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;
+  }
+};