BREAKING CHANGE: make schema paths declared with `type: { name: Strin…

…g }` create a single nested subdoc, remove `typePojoToMixed` because it is now always false

Fix #7181

docs/schematypes.pug

@@ -395,20 +395,6 @@ block content
     const Any = new Schema({ any: Object });
     const Any = new Schema({ any: Schema.Types.Mixed });
     const Any = new Schema({ any: mongoose.Mixed });
-    // Note that by default, if you're using `type`, putting _any_ POJO as the `type` will
-    // make the path mixed.
-    const Any = new Schema({
-      any: {
-        type: { foo: String }
-      } // "any" will be Mixed - everything inside is ignored.
-    });
-    // However, as of Mongoose 5.8.0, this behavior can be overridden with typePojoToMixed.
-    // In that case, it will create a single nested subdocument type instead.
-    const Any = new Schema({
-      any: {
-        type: { foo: String }
-      } // "any" will be a single nested subdocument.
-    }, {typePojoToMixed: false});
     ```
 
     Since Mixed is a schema-less type, you can change the value to anything else you

docs/subdocs.pug

@@ -237,14 +237,10 @@ block content
     reasons, this alternate declaration must be enabled via an option (either
     on the parent schema instantiation or on the mongoose instance).
     ```javascript
-    var parentSchema = new Schema({
-      child: { type: { name: 'string' } }
-    }, { typePojoToMixed: false });
-    // Equivalent
     var parentSchema = new Schema({
       child: new Schema({ name: 'string' })
     });
-    // Not equivalent!  Careful - a Mixed path is created instead!
+    // Equivalent
     var parentSchema = new Schema({
       child: { type: { name: 'string' } }
     });

lib/index.js

@@ -158,7 +158,6 @@ Mongoose.prototype.driver = require('./driver');
  * - 'toJSON': `{ transform: true, flattenDecimals: true }` by default. Overwrites default objects to [`toJSON()`](/docs/api.html#document_Document-toJSON), for determining how Mongoose documents get serialized by `JSON.stringify()`
  * - 'strict': true by default, may be `false`, `true`, or `'throw'`. Sets the default strict mode for schemas.
  * - 'selectPopulatedPaths': true by default. Set to false to opt out of Mongoose adding all fields that you `populate()` to your `select()`. The schema-level option `selectPopulatedPaths` overwrites this one.
- * - 'typePojoToMixed': true by default, may be `false` or `true`. Sets the default typePojoToMixed for schemas.
  * - 'maxTimeMS': If set, attaches [maxTimeMS](https://docs.mongodb.com/manual/reference/operator/meta/maxTimeMS/) to every query
  * - 'autoIndex': true by default. Set to false to disable automatic index creation for all models associated with this Mongoose instance.
  *

lib/schema.js

@@ -66,7 +66,6 @@ let id = 0;
  * - [toJSON](/docs/guide.html#toJSON) - object - no default
  * - [toObject](/docs/guide.html#toObject) - object - no default
  * - [typeKey](/docs/guide.html#typeKey) - string - defaults to 'type'
- * - [typePojoToMixed](/docs/guide.html#typePojoToMixed) - boolean - defaults to true. Determines whether a type set to a POJO becomes a Mixed path or a Subdocument
  * - [useNestedStrict](/docs/guide.html#useNestedStrict) - boolean - defaults to false
  * - [validateBeforeSave](/docs/guide.html#validateBeforeSave) - bool - defaults to `true`
  * - [versionKey](/docs/guide.html#versionKey): string - defaults to "__v"
@@ -414,8 +413,7 @@ Schema.prototype.defaultOptions = function(options) {
     _id: true,
     noVirtualId: false, // deprecated, use { id: false }
     id: true,
-    typeKey: 'type',
-    typePojoToMixed: 'typePojoToMixed' in baseOptions ? baseOptions.typePojoToMixed : true
+    typeKey: 'type'
   }, utils.clone(options));
 
   if (options.read) {
@@ -501,14 +499,13 @@ Schema.prototype.add = function add(obj, prefix) {
       this.add(obj[key], fullPath + '.');
     } else {
       // There IS a bona-fide type key that may also be a POJO
-      if (!this.options.typePojoToMixed && utils.isPOJO(obj[key][this.options.typeKey])) {
+      const _typeDef = obj[key][this.options.typeKey];
+      if (utils.isPOJO(_typeDef) && Object.keys(_typeDef).length > 0) {
         // If a POJO is the value of a type key, make it a subdocument
         if (prefix) {
           this.nested[prefix.substr(0, prefix.length - 1)] = true;
         }
-        // Propage `typePojoToMixed` to implicitly created schemas
-        const opts = { typePojoToMixed: false };
-        const _schema = new Schema(obj[key][this.options.typeKey], opts);
+        const _schema = new Schema(_typeDef);
         const schemaWrappedPath = Object.assign({}, obj[key], { type: _schema });
         this.path(prefix + key, schemaWrappedPath);
       } else {
@@ -929,9 +926,6 @@ Schema.prototype.interpretAsType = function(path, obj, options) {
         if (options.hasOwnProperty('strict')) {
           childSchemaOptions.strict = options.strict;
         }
-        if (options.hasOwnProperty('typePojoToMixed')) {
-          childSchemaOptions.typePojoToMixed = options.typePojoToMixed;
-        }
         const childSchema = new Schema(cast, childSchemaOptions);
         childSchema.$implicitlyCreated = true;
         return new MongooseTypes.DocumentArray(path, childSchema, obj);

lib/validoptions.js

@@ -23,8 +23,7 @@ const VALID_OPTIONS = Object.freeze([
   'useFindAndModify',
   'useNewUrlParser',
   'usePushEach',
-  'useUnifiedTopology',
-  'typePojoToMixed'
+  'useUnifiedTopology'
 ]);
 
 module.exports = VALID_OPTIONS;

test/model.indexes.test.js

@@ -362,6 +362,13 @@ describe('model', function() {
       });
 
       describe('global autoIndexes (gh-1875)', function() {
+        beforeEach(() => {
+          const Test = db.model('Test', Schema({}));
+          return Test.collection.dropIndexes();
+        });
+
+        beforeEach(() => db.deleteModel(/Test/));
+
         it('will create indexes as a default', function(done) {
           const schema = new Schema({ name: { type: String, index: true } });
           const Test = db.model('Test', schema);

test/types.embeddeddocumentdeclarative.test.js

@@ -25,30 +25,8 @@ describe('types.embeddeddocumentdeclarative', function() {
       }
     };
 
-    describe('with the default legacy behavior (typePojoToMixed=true)', function() {
+    describe('creates subdocument schema if `type` is an object with keys', function() {
       const ParentSchema = new mongoose.Schema(ParentSchemaDef);
-      it('interprets the POJO as Mixed (gh-7494)', function(done) {
-        assert.equal(ParentSchema.paths.child.instance, 'Mixed');
-        done();
-      });
-      it('does not enforce provided schema on the child path (gh-7494)', function(done) {
-        const ParentModel = mongoose.model('ParentModel-7494-EmbeddedDeclarativeMixed', ParentSchema);
-        const swampGuide = new ParentModel({
-          name: 'Swamp Guide',
-          child: {
-            name: 'Tingle',
-            mixedUp: 'very'
-          }
-        });
-        const tingle = swampGuide.toObject().child;
-
-        assert.equal(tingle.name, 'Tingle');
-        assert.equal(tingle.mixedUp, 'very');
-        done();
-      });
-    });
-    describe('with the optional subschema behavior (typePojoToMixed=false)', function() {
-      const ParentSchema = new mongoose.Schema(ParentSchemaDef, { typePojoToMixed: false });
       it('interprets the POJO as a subschema (gh-7494)', function(done) {
         assert.equal(ParentSchema.paths.child.instance, 'Embedded');
         assert.strictEqual(ParentSchema.paths.child['$isSingleNested'], true);
@@ -77,7 +55,7 @@ describe('types.embeddeddocumentdeclarative', function() {
               type: { test: String }
             }
           }]
-        }, { typePojoToMixed: false });
+        });
 
         assert.ok(schema.path('arr').schema.path('nested').instance !== 'Mixed');
         assert.ok(schema.path('arr').schema.path('nested.test') instanceof mongoose.Schema.Types.String);
@@ -94,7 +72,7 @@ describe('types.embeddeddocumentdeclarative', function() {
               }
             }
           }
-        }, { typePojoToMixed: false });
+        });
 
         assert.ok(schema.path('l1').instance !== 'Mixed');
         assert.ok(schema.path('l1.l2').instance !== 'Mixed');
@@ -112,7 +90,7 @@ describe('types.embeddeddocumentdeclarative', function() {
       }
     };
     const ParentSchemaNotMixed = new Schema(ParentSchemaDef);
-    const ParentSchemaNotSubdoc = new Schema(ParentSchemaDef, { typePojoToMixed: false });
+    const ParentSchemaNotSubdoc = new Schema(ParentSchemaDef);
     it('does not create a path for child in either option', function(done) {
       assert.equal(ParentSchemaNotMixed.paths['child.name'].instance, 'String');
       assert.equal(ParentSchemaNotSubdoc.paths['child.name'].instance, 'String');