From 94b308ec89fce0feaa21454337e15351b6a71c01 Mon Sep 17 00:00:00 2001
From: hasezoey <hasezoey@gmail.com>
Date: Tue, 4 Oct 2022 12:55:59 +0200
Subject: [PATCH 01/10] chore(mocha-fixtures): fix spelling and remove
 "example" comments (#12511)

* chore(mocha-fixtures): fix spelling and remove "example" comments

also use "MONGOOSE_REPLSET_URI" in the false case

* Update test/mocha-fixtures.js

* chore(mocha-fixtures): update comment to be more descriptive

Co-authored-by: Hafez <a.hafez852@gmail.com>
---
 test/mocha-fixtures.js | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/mocha-fixtures.js b/test/mocha-fixtures.js
index 2e537071c52..fba36267bcb 100644
--- a/test/mocha-fixtures.js
+++ b/test/mocha-fixtures.js
@@ -12,7 +12,7 @@ let mongoinstance;
 // a replset-instance for running repl-set tests
 let mongorreplset;
 
-// decide wheter to start a in-memory or not
+// decide whether to start MMS instances or use the existing URI's
 const startMemoryInstance = !process.env.MONGOOSE_TEST_URI;
 const startMemoryReplset = !process.env.MONGOOSE_REPLSET_URI;
 
@@ -24,11 +24,11 @@ module.exports.mochaGlobalSetup = async function mochaGlobalSetup() {
 
   // set some options when running in a CI
   if (process.env.CI) {
+    // this option is also set in the github-ci tests.yml, but this is just to ensure it is in any CI
     process.env.MONGOMS_PREFER_GLOBAL_PATH = '1'; // set MMS to use "~/.cache/mongodb-binaries" even when the path does not yet exist
   }
 
-  if (startMemoryInstance) { // Config to decided if an mongodb-memory-server instance should be used
-    // it's needed in global space, because we don't want to create a new instance every test-suite
+  if (startMemoryInstance) {
     mongoinstance = await mms.MongoMemoryServer.create({ instance: { args: ['--setParameter', 'ttlMonitorSleepSecs=1'], storageEngine: 'wiredTiger' } });
     instanceuri = mongoinstance.getUri();
   } else {
@@ -39,7 +39,7 @@ module.exports.mochaGlobalSetup = async function mochaGlobalSetup() {
     mongorreplset = await mms.MongoMemoryReplSet.create({ replSet: { count: 3, args: ['--setParameter', 'ttlMonitorSleepSecs=1'], storageEngine: 'wiredTiger' } }); // using 3 because even numbers can lead to vote problems
     replseturi = mongorreplset.getUri();
   } else {
-    replseturi = '';
+    replseturi = process.env.MONGOOSE_REPLSET_URI;
   }
 
   process.env.MONGOOSE_TEST_URI = instanceuri;
@@ -47,7 +47,7 @@ module.exports.mochaGlobalSetup = async function mochaGlobalSetup() {
 };
 
 module.exports.mochaGlobalTeardown = async function mochaGlobalTeardown() {
-  if (mongoinstance) { // Config to decided if an mongodb-memory-server instance should be used
+  if (mongoinstance) {
     await mongoinstance.stop();
   }
   if (mongorreplset) {

From ed3a7dfba6b9dba7e7f4655be96e076a4e0bd00b Mon Sep 17 00:00:00 2001
From: hasezoey <hasezoey@gmail.com>
Date: Tue, 4 Oct 2022 17:25:39 +0200
Subject: [PATCH 02/10] fix(types): add "estimatedDocumentCount" and
 "countDocuments" as possible hooks

plus tests

fixes #12516
---
 test/types/middleware.test.ts | 18 ++++++++++++++++++
 types/middlewares.d.ts        |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/test/types/middleware.test.ts b/test/types/middleware.test.ts
index 46c44d390e0..4b7b07d3437 100644
--- a/test/types/middleware.test.ts
+++ b/test/types/middleware.test.ts
@@ -92,6 +92,24 @@ schema.pre<Model<ITest>>('insertMany', function(next, docs: Array<ITest>) {
   next();
 });
 
+schema.pre<Query<number, any>>('count', function(next) {});
+schema.post<Query<number, any>>('count', function(count, next) {
+  expectType<number>(count);
+  next();
+});
+
+schema.pre<Query<number, any>>('estimatedDocumentCount', function(next) {});
+schema.post<Query<number, any>>('estimatedDocumentCount', function(count, next) {
+  expectType<number>(count);
+  next();
+});
+
+schema.pre<Query<number, any>>('countDocuments', function(next) {});
+schema.post<Query<number, any>>('countDocuments', function(count, next) {
+  expectType<number>(count);
+  next();
+});
+
 schema.post<Query<ITest, ITest>>('findOneAndDelete', function(res, next) {
   expectType<ITest>(res);
   next();
diff --git a/types/middlewares.d.ts b/types/middlewares.d.ts
index 0310ca0fa0a..b8e604f2dad 100644
--- a/types/middlewares.d.ts
+++ b/types/middlewares.d.ts
@@ -1,7 +1,7 @@
 declare module 'mongoose' {
 
   type MongooseDocumentMiddleware = 'validate' | 'save' | 'remove' | 'updateOne' | 'deleteOne' | 'init';
-  type MongooseQueryMiddleware = 'count' | 'deleteMany' | 'deleteOne' | 'distinct' | 'find' | 'findOne' | 'findOneAndDelete' | 'findOneAndRemove' | 'findOneAndReplace' | 'findOneAndUpdate' | 'remove' | 'replaceOne' | 'update' | 'updateOne' | 'updateMany';
+  type MongooseQueryMiddleware = 'count' | 'estimatedDocumentCount' | 'countDocuments' | 'deleteMany' | 'deleteOne' | 'distinct' | 'find' | 'findOne' | 'findOneAndDelete' | 'findOneAndRemove' | 'findOneAndReplace' | 'findOneAndUpdate' | 'remove' | 'replaceOne' | 'update' | 'updateOne' | 'updateMany';
 
   type MiddlewareOptions = { document?: boolean, query?: boolean };
   type SchemaPreOptions = MiddlewareOptions;

From b4aaf62577bcfbcc0e08de0ea4e79e6e1c39d727 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 4 Oct 2022 16:43:03 -0400
Subject: [PATCH 03/10] docs(change-streams): remove unnecessary obsolete
 comment about needing to use mongodb driver change streams

Fix #12444
---
 docs/change-streams.md | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/docs/change-streams.md b/docs/change-streams.md
index dc7eaeb9515..bc1424ccf12 100644
--- a/docs/change-streams.md
+++ b/docs/change-streams.md
@@ -65,9 +65,7 @@ exports.handler = async (event, context) => {
   context.callbackWaitsForEmptyEventLoop = false;
 
   await connectToDatabase();
-  
-  // Use MongoDB Node driver's `watch()` function, because Mongoose change streams
-  // don't support `next()` yet. See https://github.com/Automattic/mongoose/issues/11527
+
   const changeStream = await Country.watch([], { resumeAfter });
 
   // Change stream `next()` will wait forever if there are no changes. So make sure to

From e800193c76129179f6d2913148f70a12c8872046 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 4 Oct 2022 16:56:15 -0400
Subject: [PATCH 04/10] docs(subdocs): clarify that populated docs are not
 subdocs

Fix #12398
---
 docs/subdocs.md | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/docs/subdocs.md b/docs/subdocs.md
index 64b03bd19d3..7068e9c14da 100644
--- a/docs/subdocs.md
+++ b/docs/subdocs.md
@@ -11,15 +11,31 @@ const childSchema = new Schema({ name: 'string' });
 const parentSchema = new Schema({
   // Array of subdocuments
   children: [childSchema],
-  // Single nested subdocuments. Caveat: single nested subdocs only work
-  // in mongoose >= 4.2.0
+  // Single nested subdocuments
   child: childSchema
 });
 ```
 
-Aside from code reuse, one important reason to use subdocuments is to create
-a path where there would otherwise not be one to allow for validation over
-a group of fields (e.g. dateRange.fromDate <= dateRange.toDate).
+Note that populated documents are **not** subdocuments in Mongoose.
+Subdocument data is embedded in the top-level document.
+Referenced documents are separate top-level documents.
+
+```javascript
+const childSchema = new Schema({ name: 'string' });
+const Child = mongoose.model('Child', childSchema);
+
+const parentSchema = new Schema({
+  child: {
+    type: mongoose.ObjectId,
+    ref: 'Child'
+  }
+});
+const Parent = mongoose.model('Parent', parentSchema);
+
+const doc = await Parent.findOne().populate('child');
+// NOT a subdocument. `doc.child` is a separate top-level document.
+doc.child;
+```
 
 <ul class="toc">
   <li><a href="#what-is-a-subdocument-">What is a Subdocument?</a></li>

From a15242dc3ad8f5648e4f8c868589b8f427a5ef3b Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 4 Oct 2022 17:16:30 -0400
Subject: [PATCH 05/10] fix(types): indicate that
 Schema.prototype.discriminator() returns `this`

Fix #12457
---
 test/types/schema.test.ts | 8 ++------
 types/index.d.ts          | 2 +-
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/test/types/schema.test.ts b/test/types/schema.test.ts
index 66ed8ee28d9..e400dfa0ccf 100644
--- a/test/types/schema.test.ts
+++ b/test/types/schema.test.ts
@@ -570,9 +570,7 @@ export type AutoTypedSchemaType = {
 // discriminator
 const eventSchema = new Schema<{ message: string }>({ message: String }, { discriminatorKey: 'kind' });
 const batchSchema = new Schema<{ name: string }>({ name: String }, { discriminatorKey: 'kind' });
-const discriminatedSchema = batchSchema.discriminator('event', eventSchema);
-
-expectType<Schema<Omit<{ name: string }, 'message'> & { message: string }>>(discriminatedSchema);
+batchSchema.discriminator('event', eventSchema);
 
 // discriminator statics
 const eventSchema2 = new Schema({ message: String }, { discriminatorKey: 'kind', statics: { static1: function() {
@@ -581,9 +579,7 @@ const eventSchema2 = new Schema({ message: String }, { discriminatorKey: 'kind',
 const batchSchema2 = new Schema({ name: String }, { discriminatorKey: 'kind', statics: { static2: function() {
   return 1;
 } } });
-const discriminatedSchema2 = batchSchema2.discriminator('event', eventSchema2);
-
-expectAssignable<Schema<Omit<{ name: string }, 'message'> & { message: string }, Model<any>, {}, {}, {}, { static1(): number; static2(): number; }>>(discriminatedSchema2);
+batchSchema2.discriminator('event', eventSchema2);
 
 function gh11828() {
   interface IUser {
diff --git a/types/index.d.ts b/types/index.d.ts
index ba560b634dd..5fc0853987b 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -208,7 +208,7 @@ declare module 'mongoose' {
     /** Returns a copy of this schema */
     clone<T = this>(): T;
 
-    discriminator<DisSchema = Schema>(name: string, schema: DisSchema): DiscriminatorSchema<DocType, M, TInstanceMethods, TQueryHelpers, TVirtuals, TStaticMethods, DisSchema>;
+    discriminator<DisSchema = Schema>(name: string, schema: DisSchema): this;
 
     /** Returns a new schema that has the picked `paths` from this schema. */
     pick<T = this>(paths: string[], options?: SchemaOptions): T;

From 167f68284098dcb67d733edc540cce596db44d4d Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 4 Oct 2022 18:26:03 -0400
Subject: [PATCH 06/10] fix(document): set defaults on subdocuments underneath
 init-ed single nested subdocument

Fix #12515
---
 lib/schema/SubdocumentPath.js |  1 +
 test/document.test.js         | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/schema/SubdocumentPath.js b/lib/schema/SubdocumentPath.js
index e748d6a5026..46ea86673e0 100644
--- a/lib/schema/SubdocumentPath.js
+++ b/lib/schema/SubdocumentPath.js
@@ -174,6 +174,7 @@ SubdocumentPath.prototype.cast = function(val, doc, init, priorVal, options) {
     subdoc = new Constructor(void 0, selected, doc, false, { defaults: false });
     subdoc.$init(val);
     applyDefaults(subdoc, selected);
+    delete subdoc.$__.defaults;
   } else {
     if (Object.keys(val).length === 0) {
       return new Constructor({}, selected, doc, undefined, options);
diff --git a/test/document.test.js b/test/document.test.js
index ca2aca278d9..eebea364b3c 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -11865,6 +11865,33 @@ describe('document', function() {
     assert.strictEqual(called, 1);
   });
 
+  it('applies defaults to pushed subdocs after initing document (gh-12515)', async function() {
+    const animalSchema = new Schema({ title: String });
+    const animalsSchema = new Schema({
+      species: [animalSchema],
+      totalAnimals: Number
+    });
+    const Userschema = new Schema({
+      animals: animalsSchema
+    });
+    const UserModel = db.model('User', Userschema);
+
+    const doc = new UserModel();
+    doc.animals = { totalAnimals: 1 };
+    doc.animals.species = [{ title: 'Lion' }];
+    await doc.save();
+    // once created we fetch it again
+    let user = await UserModel.findById(doc._id);
+
+    // add new animal
+    user.animals.species.push({ title: 'Elephant' });
+    await user.save();
+    assert.ok(user.animals.species[1]._id);
+    user = await UserModel.collection.findOne({ _id: user._id });
+
+    assert.ok(user.animals.species[1]._id);
+  });
+
   it('If the field does not exist, $inc should create it and set is value to the specified one (gh-12435)', async function() {
     const schema = new mongoose.Schema({
       name: String,

From b0edca9f6d2ce957194f8229744140c08b325fb5 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 5 Oct 2022 10:25:14 -0400
Subject: [PATCH 07/10] fix: quick fix so `defaults` is unset before init

---
 lib/schema/SubdocumentPath.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/schema/SubdocumentPath.js b/lib/schema/SubdocumentPath.js
index 46ea86673e0..1eb65207d85 100644
--- a/lib/schema/SubdocumentPath.js
+++ b/lib/schema/SubdocumentPath.js
@@ -172,9 +172,9 @@ SubdocumentPath.prototype.cast = function(val, doc, init, priorVal, options) {
   options = Object.assign({}, options, { priorDoc: priorVal });
   if (init) {
     subdoc = new Constructor(void 0, selected, doc, false, { defaults: false });
+    delete subdoc.$__.defaults;
     subdoc.$init(val);
     applyDefaults(subdoc, selected);
-    delete subdoc.$__.defaults;
   } else {
     if (Object.keys(val).length === 0) {
       return new Constructor({}, selected, doc, undefined, options);

From 9093f7cda8938edc219298ab3083ee92ee00f30e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 5 Oct 2022 11:00:20 -0400
Subject: [PATCH 08/10] docs(models): add section on MongoDB Views

Fix #5694
---
 docs/models.md | 67 ++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 57 insertions(+), 10 deletions(-)

diff --git a/docs/models.md b/docs/models.md
index f72f716154a..b68f2eac7e7 100644
--- a/docs/models.md
+++ b/docs/models.md
@@ -1,4 +1,4 @@
-## Models
+# Models
 
 [Models](./api.html#model-js) are fancy constructors compiled from
 `Schema` definitions. An instance of a model is called a
@@ -11,6 +11,7 @@ reading documents from the underlying MongoDB database.
 * [Deleting](#deleting)
 * [Updating](#updating)
 * [Change Streams](#change-streams)
+* [Views](#views)
 
 <h3 id="compiling"><a href="#compiling">Compiling your first model</a></h3>
 
@@ -31,7 +32,7 @@ in the database.
 you've added everything you want to `schema`, including hooks,
 before calling `.model()`!
 
-### Constructing Documents
+## Constructing Documents
 
 An instance of a model is called a [document](./documents.html). Creating
 them and saving to the database is easy.
@@ -73,7 +74,7 @@ const connection = mongoose.createConnection('mongodb://localhost:27017/test');
 const Tank = connection.model('Tank', yourSchema);
 ```
 
-### Querying
+## Querying
 
 Finding documents is easy with Mongoose, which supports the [rich](http://www.mongodb.org/display/DOCS/Advanced+Queries) query syntax of MongoDB. Documents can be retrieved using a `model`'s [find](./api.html#model_Model-find), [findById](./api.html#model_Model-findById), [findOne](./api.html#model_Model-findOne), or [where](./api.html#model_Model-where) static methods.
 
@@ -83,7 +84,7 @@ Tank.find({ size: 'small' }).where('createdDate').gt(oneYearAgo).exec(callback);
 
 See the chapter on [queries](./queries.html) for more details on how to use the [Query](./api.html#query-js) api.
 
-### Deleting
+## Deleting
 
 Models have static `deleteOne()` and `deleteMany()` functions
 for removing all documents matching the given `filter`.
@@ -95,7 +96,7 @@ Tank.deleteOne({ size: 'large' }, function (err) {
 });
 ```
 
-### Updating
+## Updating
 
 Each `model` has its own `update` method for modifying documents in the
 database without returning them to your application. See the
@@ -112,9 +113,7 @@ _If you want to update a single document in the db and return it to your
 application, use [findOneAndUpdate](./api.html#model_Model-findOneAndUpdate)
 instead._
 
-### Change Streams
-
-_New in MongoDB 3.6.0 and Mongoose 5.0.0_
+## Change Streams
 
 [Change streams](https://docs.mongodb.com/manual/changeStreams/) provide
 a way for you to listen to all inserts and updates going through your
@@ -154,10 +153,58 @@ The output from the above [async function](http://thecodebarbarian.com/80-20-gui
 
 You can read more about [change streams in mongoose in this blog post](http://thecodebarbarian.com/a-nodejs-perspective-on-mongodb-36-change-streams.html#change-streams-in-mongoose).
 
-### Yet more
+## Views
+
+[MongoDB Views](https://www.mongodb.com/docs/manual/core/views) are essentially read-only collections that contain data computed from other collections using [aggregations](./api/aggregate.html).
+In Mongoose, you should define a separate Model for each of your Views.
+You can also create a View using [`createCollection()`](./api/model.html#model_Model-createCollection).
+
+The following example shows how you can create a new `RedactedUser` View on a `User` Model that hides potentially sensitive information, like name and email.
+
+```javascript
+// Make sure to disable `autoCreate` and `autoIndex` for Views,
+// because you want to create the collection manually.
+const userSchema = new Schema({
+  name: String,
+  email: String,
+  roles: [String]
+}, { autoCreate: false, autoIndex: false });
+const User = mongoose.model('User', userSchema);
+
+const RedactedUser = mongoose.model('RedactedUser', userSchema);
+
+// First, create the User model's underlying collection...
+await User.createCollection();
+// Then create the `RedactedUser` model's underlying collection
+// as a View.
+await RedactedUser.createCollection({
+  viewOn: 'users', // Set `viewOn` to the collection name, **not** model name.
+  pipeline: [
+    {
+      $set: {
+        name: { $concat: [{ $substr: ['$name', 0, 3] }, '...'] },
+        email: { $concat: [{ $substr: ['$email', 0, 3] }, '...'] }
+      }
+    }
+  ]
+});
+
+await User.create([
+  { name: 'John Smith', email: 'john.smith@gmail.com', roles: ['user'] },
+  { name: 'Bill James', email: 'bill@acme.co', roles: ['user', 'admin'] }
+]);
+
+// [{ _id: ..., name: 'Bil...', email: 'bil...', roles: ['user', 'admin'] }]
+console.log(await RedactedUser.find({ roles: 'admin' }));
+```
+
+Note that Mongoose does **not** currently enforce that Views are read-only.
+If you attempt to `save()` a document from a View, you will get an error from the MongoDB server.
+
+## Yet more
 
 The [API docs](./api.html#model_Model) cover many additional methods available like [count](./api.html#model_Model-count), [mapReduce](./api.html#model_Model-mapReduce), [aggregate](./api.html#model_Model-aggregate), and [more](./api.html#model_Model-findOneAndRemove).
 
-### Next Up
+## Next Up
 
 Now that we've covered `Models`, let's take a look at [Documents](/docs/documents.html).

From 630bd3738ea237934ac4f246fb97d868412b5d70 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 5 Oct 2022 11:04:04 -0400
Subject: [PATCH 09/10] test: cover a couple of extra cases for #12515

---
 test/document.test.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/document.test.js b/test/document.test.js
index eebea364b3c..2d38adc8629 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -11886,9 +11886,11 @@ describe('document', function() {
     // add new animal
     user.animals.species.push({ title: 'Elephant' });
     await user.save();
+    assert.ok(user.animals.species[0]._id);
     assert.ok(user.animals.species[1]._id);
     user = await UserModel.collection.findOne({ _id: user._id });
 
+    assert.ok(user.animals.species[0]._id);
     assert.ok(user.animals.species[1]._id);
   });
 

From 2691f74df958bdf9b5dfeb6ce6b4e340df7c8a7d Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 5 Oct 2022 11:30:00 -0400
Subject: [PATCH 10/10] Update docs/models.md

Co-authored-by: hasezoey <hasezoey@gmail.com>
---
 docs/models.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/models.md b/docs/models.md
index b68f2eac7e7..565cc2d8a7b 100644
--- a/docs/models.md
+++ b/docs/models.md
@@ -13,7 +13,7 @@ reading documents from the underlying MongoDB database.
 * [Change Streams](#change-streams)
 * [Views](#views)
 
-<h3 id="compiling"><a href="#compiling">Compiling your first model</a></h3>
+<h2 id="compiling"><a href="#compiling">Compiling your first model</a></h3>
 
 When you call `mongoose.model()` on a schema, Mongoose _compiles_ a model
 for you.