fix: use lazy loading to avoid browserDocument edge case

Fix #5842

Author: vkarpov15

lib/schema/array.js

@@ -15,15 +15,16 @@ var Types = {
   ObjectId: require('./objectid'),
   Buffer: require('./buffer')
 };
-var MongooseArray = require('../types').Array;
-var EmbeddedDoc = require('../types').Embedded;
 var Mixed = require('./mixed');
 var cast = require('../cast');
 var util = require('util');
 var utils = require('../utils');
 var castToNumber = require('./operators/helpers').castToNumber;
 var geospatial = require('./operators/geospatial');
 
+var MongooseArray;
+var EmbeddedDoc;
+
 /**
  * Array SchemaType constructor
  *
@@ -35,6 +36,9 @@ var geospatial = require('./operators/geospatial');
  */
 
 function SchemaArray(key, cast, options, schemaOptions) {
+  // lazy load
+  EmbeddedDoc || (EmbeddedDoc = require('../types').Embedded);
+
   var typeKey = 'type';
   if (schemaOptions && schemaOptions.typeKey) {
     typeKey = schemaOptions.typeKey;
@@ -155,6 +159,9 @@ SchemaArray.prototype.applyGetters = function(value, scope) {
  */
 
 SchemaArray.prototype.cast = function(value, doc, init) {
+  // lazy load
+  MongooseArray || (MongooseArray = require('../types').Array);
+
   if (Array.isArray(value)) {
     if (!value.length && doc) {
       var indexes = doc.schema.indexedPaths();

lib/schema/buffer.js

@@ -5,7 +5,7 @@
 var handleBitwiseOperator = require('./operators/bitwise');
 var utils = require('../utils');
 
-var MongooseBuffer = require('../types').Buffer;
+var MongooseBuffer = require('../types/buffer');
 var SchemaType = require('../schematype');
 
 var Binary = MongooseBuffer.Binary;

lib/schema/documentarray.js

@@ -8,13 +8,14 @@ var ArrayType = require('./array');
 var CastError = require('../error/cast');
 var Document = require('../document');
 var EventEmitter = require('events').EventEmitter;
-var MongooseDocumentArray = require('../types/documentarray');
 var SchemaType = require('../schematype');
-var Subdocument = require('../types/embedded');
 var discriminator = require('../services/model/discriminator');
 var util = require('util');
 var utils = require('../utils');
 
+var MongooseDocumentArray;
+var Subdocument;
+
 /**
  * SubdocsArray SchemaType constructor
  *
@@ -66,6 +67,8 @@ DocumentArray.prototype.constructor = DocumentArray;
  */
 
 function _createConstructor(schema, options) {
+  Subdocument || (Subdocument = require('../types/embedded'));
+
   // compile an embedded document for this schema
   function EmbeddedDocument() {
     Subdocument.apply(this, arguments);
@@ -130,6 +133,9 @@ DocumentArray.prototype.discriminator = function(name, schema) {
  */
 
 DocumentArray.prototype.doValidate = function(array, fn, scope, options) {
+  // lazy load
+  MongooseDocumentArray || (MongooseDocumentArray = require('../types/documentarray'));
+
   var _this = this;
   SchemaType.prototype.doValidate.call(this, array, function(err) {
     if (err) {
@@ -251,6 +257,9 @@ DocumentArray.prototype.doValidateSync = function(array, scope) {
  */
 
 DocumentArray.prototype.cast = function(value, doc, init, prev, options) {
+  // lazy load
+  MongooseDocumentArray || (MongooseDocumentArray = require('../types/documentarray'));
+
   var selected;
   var subdoc;
   var i;

lib/schema/embedded.js

@@ -7,11 +7,12 @@
 var $exists = require('./operators/exists');
 var EventEmitter = require('events').EventEmitter;
 var SchemaType = require('../schematype');
-var Subdocument = require('../types/subdocument');
 var castToNumber = require('./operators/helpers').castToNumber;
 var discriminator = require('../services/model/discriminator');
 var geospatial = require('./operators/geospatial');
 
+var Subdocument;
+
 module.exports = Embedded;
 
 /**
@@ -43,6 +44,9 @@ Embedded.prototype = Object.create(SchemaType.prototype);
  */
 
 function _createConstructor(schema) {
+  // lazy load
+  Subdocument || (Subdocument = require('../types/subdocument'));
+
   var _embedded = function SingleNested(value, path, parent) {
     var _this = this;