From 97e5a0eab8920b6be8cd3a9f02f4a0e74d32698c Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 22 Dec 2022 12:43:46 -0500
Subject: [PATCH 01/18] fix(model): respect discriminators with
 `Model.validate()`

Fix #12621
---
 lib/model.js                |   7 +-
 test/model.test.js          | 113 ----------------------------
 test/model.validate.test.js | 146 ++++++++++++++++++++++++++++++++++++
 3 files changed, 152 insertions(+), 114 deletions(-)
 create mode 100644 test/model.validate.test.js

diff --git a/lib/model.js b/lib/model.js
index 51d33bf5a41..a146eea1ef0 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -36,6 +36,7 @@ const assignVals = require('./helpers/populate/assignVals');
 const castBulkWrite = require('./helpers/model/castBulkWrite');
 const createPopulateQueryFilter = require('./helpers/populate/createPopulateQueryFilter');
 const getDefaultBulkwriteResult = require('./helpers/getDefaultBulkwriteResult');
+const getSchemaDiscriminatorByValue = require('./helpers/discriminator/getSchemaDiscriminatorByValue');
 const discriminator = require('./helpers/model/discriminator');
 const firstKey = require('./helpers/firstKey');
 const each = require('./helpers/each');
@@ -4474,7 +4475,11 @@ Model.validate = function validate(obj, pathsToValidate, context, callback) {
   }
 
   return this.db.base._promiseOrCallback(callback, cb => {
-    const schema = this.schema;
+    let schema = this.schema;
+    const discriminatorKey = schema.options.discriminatorKey;
+    if (schema.discriminators != null && obj != null && obj[discriminatorKey] != null) {
+      schema = getSchemaDiscriminatorByValue(schema, obj[discriminatorKey]) || schema;
+    }
     let paths = Object.keys(schema.paths);
 
     if (pathsToValidate != null) {
diff --git a/test/model.test.js b/test/model.test.js
index 6157f53e3b5..fb48340f063 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -7456,119 +7456,6 @@ describe('Model', function() {
     });
   });
 
-  it('Model.validate() (gh-7587)', async function() {
-    const Model = db.model('Test', new Schema({
-      name: {
-        first: {
-          type: String,
-          required: true
-        },
-        last: {
-          type: String,
-          required: true
-        }
-      },
-      age: {
-        type: Number,
-        required: true
-      },
-      comments: [{ name: { type: String, required: true } }]
-    }));
-
-
-    let err = null;
-    let obj = null;
-
-    err = await Model.validate({ age: null }, ['age']).
-      then(() => null, err => err);
-    assert.ok(err);
-    assert.deepEqual(Object.keys(err.errors), ['age']);
-
-    err = await Model.validate({ name: {} }, ['name']).
-      then(() => null, err => err);
-    assert.ok(err);
-    assert.deepEqual(Object.keys(err.errors), ['name.first', 'name.last']);
-
-    obj = { name: { first: 'foo' } };
-    err = await Model.validate(obj, ['name']).
-      then(() => null, err => err);
-    assert.ok(err);
-    assert.deepEqual(Object.keys(err.errors), ['name.last']);
-
-    obj = { comments: [{ name: 'test' }, {}] };
-    err = await Model.validate(obj, ['comments']).
-      then(() => null, err => err);
-    assert.ok(err);
-    assert.deepEqual(Object.keys(err.errors), ['comments.name']);
-
-    obj = { age: '42' };
-    await Model.validate(obj, ['age']);
-    assert.strictEqual(obj.age, 42);
-  });
-
-  it('Model.validate(...) validates paths in arrays (gh-8821)', async function() {
-    const userSchema = new Schema({
-      friends: [{ type: String, required: true, minlength: 3 }]
-    });
-
-    const User = db.model('User', userSchema);
-
-    const err = await User.validate({ friends: [null, 'A'] }).catch(err => err);
-
-    assert.ok(err.errors['friends.0']);
-    assert.ok(err.errors['friends.1']);
-
-  });
-
-  it('Model.validate() works with arrays (gh-10669)', async function() {
-    const testSchema = new Schema({
-      docs: [String]
-    });
-
-    const Test = db.model('Test', testSchema);
-
-    const test = { docs: ['6132655f2cdb9d94eaebc09b'] };
-
-    const err = await Test.validate(test);
-    assert.ifError(err);
-  });
-
-  it('Model.validate(...) uses document instance as context by default (gh-10132)', async function() {
-    const userSchema = new Schema({
-      name: {
-        type: String,
-        required: function() {
-          return this.nameRequired;
-        }
-      },
-      nameRequired: Boolean
-    });
-
-    const User = db.model('User', userSchema);
-
-    const user = new User({ name: 'test', nameRequired: false });
-    const err = await User.validate(user).catch(err => err);
-
-    assert.ifError(err);
-
-  });
-  it('Model.validate(...) uses object as context by default (gh-10346)', async() => {
-
-    const userSchema = new mongoose.Schema({
-      name: { type: String, required: true },
-      age: { type: Number, required() {return this && this.name === 'John';} }
-    });
-
-    const User = db.model('User', userSchema);
-
-    const err1 = await User.validate({ name: 'John' }).then(() => null, err => err);
-    assert.ok(err1);
-
-    const err2 = await User.validate({ name: 'Sam' }).then(() => null, err => err);
-    assert.ok(err2 === null);
-
-  });
-
   it('sets correct `Document#op` with `save()` (gh-8439)', function() {
     const schema = Schema({ name: String });
     const ops = [];
diff --git a/test/model.validate.test.js b/test/model.validate.test.js
new file mode 100644
index 00000000000..877d83d90f0
--- /dev/null
+++ b/test/model.validate.test.js
@@ -0,0 +1,146 @@
+'use strict';
+
+const start = require('./common');
+
+const assert = require('assert');
+
+const mongoose = start.mongoose;
+const Schema = mongoose.Schema;
+
+describe('model: validate: ', function() {
+  afterEach(() => mongoose.deleteModel(/.*/));
+
+  it('Model.validate() (gh-7587)', async function() {
+    const Model = mongoose.model('Test', new Schema({
+      name: {
+        first: {
+          type: String,
+          required: true
+        },
+        last: {
+          type: String,
+          required: true
+        }
+      },
+      age: {
+        type: Number,
+        required: true
+      },
+      comments: [{ name: { type: String, required: true } }]
+    }));
+
+
+    let err = null;
+    let obj = null;
+
+    err = await Model.validate({ age: null }, ['age']).
+      then(() => null, err => err);
+    assert.ok(err);
+    assert.deepEqual(Object.keys(err.errors), ['age']);
+
+    err = await Model.validate({ name: {} }, ['name']).
+      then(() => null, err => err);
+    assert.ok(err);
+    assert.deepEqual(Object.keys(err.errors), ['name.first', 'name.last']);
+
+    obj = { name: { first: 'foo' } };
+    err = await Model.validate(obj, ['name']).
+      then(() => null, err => err);
+    assert.ok(err);
+    assert.deepEqual(Object.keys(err.errors), ['name.last']);
+
+    obj = { comments: [{ name: 'test' }, {}] };
+    err = await Model.validate(obj, ['comments']).
+      then(() => null, err => err);
+    assert.ok(err);
+    assert.deepEqual(Object.keys(err.errors), ['comments.name']);
+
+    obj = { age: '42' };
+    await Model.validate(obj, ['age']);
+    assert.strictEqual(obj.age, 42);
+  });
+
+  it('Model.validate(...) validates paths in arrays (gh-8821)', async function() {
+    const userSchema = new Schema({
+      friends: [{ type: String, required: true, minlength: 3 }]
+    });
+
+    const User = mongoose.model('User', userSchema);
+
+    const err = await User.validate({ friends: [null, 'A'] }).catch(err => err);
+
+    assert.ok(err.errors['friends.0']);
+    assert.ok(err.errors['friends.1']);
+  });
+
+  it('Model.validate(...) respects discriminators (gh-12621)', async function() {
+    const CatSchema = new Schema({ meows: { type: Boolean, required: true } });
+    const DogSchema = new Schema({ barks: { type: Boolean, required: true } });
+    const AnimalSchema = new Schema(
+      { id: String },
+      { discriminatorKey: 'kind' }
+    );
+    AnimalSchema.discriminator('cat', CatSchema);
+    AnimalSchema.discriminator('dog', DogSchema);
+
+    const Animal = mongoose.model('Test', AnimalSchema);
+
+    const invalidPet1 = new Animal({
+      id: '123',
+      kind: 'dog',
+      meows: true
+    });
+
+    const err = await Animal.validate(invalidPet1).then(() => null, err => err);
+    assert.ok(err);
+    assert.ok(err.errors['barks']);
+  });
+
+  it('Model.validate() works with arrays (gh-10669)', async function() {
+    const testSchema = new Schema({
+      docs: [String]
+    });
+
+    const Test = mongoose.model('Test', testSchema);
+
+    const test = { docs: ['6132655f2cdb9d94eaebc09b'] };
+
+    const err = await Test.validate(test);
+    assert.ifError(err);
+  });
+
+  it('Model.validate(...) uses document instance as context by default (gh-10132)', async function() {
+    const userSchema = new Schema({
+      name: {
+        type: String,
+        required: function() {
+          return this.nameRequired;
+        }
+      },
+      nameRequired: Boolean
+    });
+
+    const User = mongoose.model('User', userSchema);
+
+    const user = new User({ name: 'test', nameRequired: false });
+    const err = await User.validate(user).catch(err => err);
+
+    assert.ifError(err);
+
+  });
+  it('Model.validate(...) uses object as context by default (gh-10346)', async() => {
+
+    const userSchema = new mongoose.Schema({
+      name: { type: String, required: true },
+      age: { type: Number, required() {return this && this.name === 'John';} }
+    });
+
+    const User = mongoose.model('User', userSchema);
+
+    const err1 = await User.validate({ name: 'John' }).then(() => null, err => err);
+    assert.ok(err1);
+
+    const err2 = await User.validate({ name: 'Sam' }).then(() => null, err => err);
+    assert.ok(err2 === null);
+  });
+});

From bb874d9f236b11bff37e7be3cad1f811b44f254e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 22 Dec 2022 13:56:10 -0500
Subject: [PATCH 02/18] docs(typescript): make note about recommending `strict`
 mode when using auto typed schemas

Re: #12420
---
 docs/typescript/schemas.md | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/docs/typescript/schemas.md b/docs/typescript/schemas.md
index 656c058d5c6..80a86ed126d 100644
--- a/docs/typescript/schemas.md
+++ b/docs/typescript/schemas.md
@@ -1,11 +1,9 @@
 # Schemas in TypeScript
 
 Mongoose [schemas](../guide.html) are how you tell Mongoose what your documents look like.
-Mongoose schemas are separate from TypeScript interfaces, so you need to define both a _document interface_ and a _schema_ until V6.3.1.
-Mongoose supports auto typed schemas so you don't need to define additional typescript interface anymore but you are still able to do so.
-Mongoose provides a `InferSchemaType`, which infers the type of the auto typed schema document when needed.
+Mongoose schemas are separate from TypeScript interfaces, so you need to either define both a _document interface_ and a _schema_; or rely on Mongoose to automatically infer the type from the schema definition.
 
-`Until mongoose V6.3.1:`
+### Separate document interface definition
 
 ```typescript
 import { Schema } from 'mongoose';
@@ -25,7 +23,12 @@ const schema = new Schema<User>({
 });
 ```
 
-`another approach:`
+By default, Mongoose does **not** check if your document interface lines up with your schema.
+For example, the above code won't throw an error if `email` is optional in the document interface, but `required` in `schema`.
+
+### Automatic type inference
+
+Mongoose can also automatically infer the document type from your schema definition as follows.
 
 ```typescript
 import { Schema, InferSchemaType } from 'mongoose';
@@ -53,11 +56,16 @@ type User = InferSchemaType<typeof schema>;
 //   avatar?: string;
 // }
 
-
+// `UserModel` will have `name: string`, etc.
+const UserModel = mongoose.model('User', schema);
 ```
 
-By default, Mongoose does **not** check if your document interface lines up with your schema.
-For example, the above code won't throw an error if `email` is optional in the document interface, but `required` in `schema`.
+There are a few caveats for using automatic type inference:
+
+1. You need to set `strict: true` in your `tsconfig.json` or `--strict` if running `tsc`. There are [known issues](https://github.com/Automattic/mongoose/issues/12420) with automatic type inference with strict mode disabled.
+2. You need to define your schema in the `new Schema()` call. Don't assign your schema definition to a temporary variable. Doing something like `const schemaDefinition = { name: String }; const schema = new Schema(schemaDefinition);` will not work.
+
+If automatic type inference doesn't work for you, you can always fall back to document interface definitions.
 
 ## Generic parameters
 

From 9f09f92b5fe524464637bc3f92a206c31fe9844e Mon Sep 17 00:00:00 2001
From: hasezoey <hasezoey@gmail.com>
Date: Thu, 22 Dec 2022 20:08:34 +0100
Subject: [PATCH 03/18] test(model.validate): change "afterEach" to
 "beforeEach"

---
 test/model.validate.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/model.validate.test.js b/test/model.validate.test.js
index 877d83d90f0..d58cb57ebcd 100644
--- a/test/model.validate.test.js
+++ b/test/model.validate.test.js
@@ -8,7 +8,7 @@ const mongoose = start.mongoose;
 const Schema = mongoose.Schema;
 
 describe('model: validate: ', function() {
-  afterEach(() => mongoose.deleteModel(/.*/));
+  beforeEach(() => mongoose.deleteModel(/.*/));
 
   it('Model.validate() (gh-7587)', async function() {
     const Model = mongoose.model('Test', new Schema({

From 1482a1d27bae4c1e8d1b8263f32ccb95b0d8b23b Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 22 Dec 2022 21:32:46 -0500
Subject: [PATCH 04/18] fix(schema): propagate strictQuery to implicitly
 created schemas for embedded discriminators

Fix #12796
---
 lib/schema.js                     | 3 +++
 test/schema.documentarray.test.js | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/lib/schema.js b/lib/schema.js
index 70558e06f24..0bd2a8aadcd 100644
--- a/lib/schema.js
+++ b/lib/schema.js
@@ -1250,6 +1250,9 @@ Schema.prototype.interpretAsType = function(path, obj, options) {
         if (options.hasOwnProperty('strict')) {
           childSchemaOptions.strict = options.strict;
         }
+        if (options.hasOwnProperty('strictQuery')) {
+          childSchemaOptions.strictQuery = options.strictQuery;
+        }
 
         if (this._userProvidedOptions.hasOwnProperty('_id')) {
           childSchemaOptions._id = this._userProvidedOptions._id;
diff --git a/test/schema.documentarray.test.js b/test/schema.documentarray.test.js
index 3217e165d88..d9ccb6c1f6b 100644
--- a/test/schema.documentarray.test.js
+++ b/test/schema.documentarray.test.js
@@ -75,6 +75,15 @@ describe('schema.documentarray', function() {
     done();
   });
 
+  it('propagates strictQuery to implicitly created schemas (gh-12796)', function() {
+    const schema = new Schema({
+      arr: [{ name: String }]
+    }, { strictQuery: 'throw' });
+
+    assert.equal(schema.childSchemas.length, 1);
+    assert.equal(schema.childSchemas[0].schema.options.strictQuery, 'throw');
+  });
+
   it('supports set with array of document arrays (gh-7799)', function() {
     const subSchema = new Schema({
       title: String

From 730abafc214d74c2bc6dac43a71bf14f11253df8 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 23 Dec 2022 10:51:26 -0500
Subject: [PATCH 05/18] test(model): make timeseries test more durable by
 avoiding autoIndex and drop/init race

Fix #12643
---
 test/model.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/model.test.js b/test/model.test.js
index 6157f53e3b5..5728e286114 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -6916,10 +6916,12 @@ describe('Model', function() {
           granularity: 'hours'
         },
         autoCreate: false,
+        autoIndex: false,
         expireAfterSeconds: 86400
       });
 
-      const Test = db.model('Test', schema);
+      const Test = db.model('Test', schema, 'Test');
+      await Test.init();
 
       await Test.collection.drop().catch(() => {});
       await Test.createCollection();

From 8d8d7a7a017abcd3aa495bff81afc3f7d0143442 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 23 Dec 2022 10:57:28 -0500
Subject: [PATCH 06/18] Update model.validate.test.js

---
 test/model.validate.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/model.validate.test.js b/test/model.validate.test.js
index d58cb57ebcd..877d83d90f0 100644
--- a/test/model.validate.test.js
+++ b/test/model.validate.test.js
@@ -8,7 +8,7 @@ const mongoose = start.mongoose;
 const Schema = mongoose.Schema;
 
 describe('model: validate: ', function() {
-  beforeEach(() => mongoose.deleteModel(/.*/));
+  afterEach(() => mongoose.deleteModel(/.*/));
 
   it('Model.validate() (gh-7587)', async function() {
     const Model = mongoose.model('Test', new Schema({

From ad2446c367dd5d1c5e21d7f6428d001744a095f6 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 23 Dec 2022 11:40:51 -0500
Subject: [PATCH 07/18] docs: store content with associated version re: #12548

---
 docs/search.js | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/docs/search.js b/docs/search.js
index 8aa7d4c6455..83615f0ca96 100644
--- a/docs/search.js
+++ b/docs/search.js
@@ -6,6 +6,7 @@ const filemap = require('./source');
 const fs = require('fs');
 const pug = require('pug');
 const mongoose = require('../');
+let { version } = require('../package.json');
 
 const { marked: markdown } = require('marked');
 const highlight = require('highlight.js');
@@ -15,10 +16,14 @@ markdown.setOptions({
   }
 });
 
+// 5.13.5 -> 5.x, 6.8.2 -> 6.x, etc.
+version = version.slice(0, version.indexOf('.')) + '.x';
+
 const contentSchema = new mongoose.Schema({
   title: { type: String, required: true },
   body: { type: String, required: true },
-  url: { type: String, required: true }
+  url: { type: String, required: true },
+  version: { type: String, required: true, default: version }
 });
 contentSchema.index({ title: 'text', body: 'text' });
 const Content = mongoose.model('Content', contentSchema, 'Content');
@@ -28,7 +33,6 @@ const files = Object.keys(filemap);
 
 for (const filename of files) {
   const file = filemap[filename];
-  console.log(file)
   if (file.api) {
     // API docs are special, raw content is in the `docs` property
     for (const _class of file.docs) {
@@ -115,8 +119,11 @@ run().catch(error => console.error(error.stack));
 async function run() {
   await mongoose.connect(config.uri, { dbName: 'mongoose' });
 
-  await Content.deleteMany({});
+  await Content.deleteMany({ version });
   for (const content of contents) {
+    if (version !== '6.x') {
+      content.url = `/docs/${version}/docs/${content.url}`;
+    }
     await content.save();
   }
 

From 3f675a93612b279543b90c4ed30d5abbcb9245d3 Mon Sep 17 00:00:00 2001
From: hasezoey <hasezoey@gmail.com>
Date: Fri, 23 Dec 2022 18:22:39 +0100
Subject: [PATCH 08/18] test(query.test): add write-concern option in hopes
 this fixes some inconsistent tests in replica set mode

---
 test/query.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/query.test.js b/test/query.test.js
index a02a37896d0..3d1220a0cc4 100644
--- a/test/query.test.js
+++ b/test/query.test.js
@@ -1564,7 +1564,7 @@ describe('Query', function() {
       const Product = db.model('Product', productSchema);
       Product.create(
         { numbers: [3, 4, 5] },
-        { strings: 'hi there'.split(' ') }, function(err, doc1, doc2) {
+        { strings: 'hi there'.split(' '), w: 'majority' }, function(err, doc1, doc2) {
           assert.ifError(err);
           Product.find().setOptions({ limit: 1, sort: { _id: -1 }, read: 'n' }).exec(function(err, docs) {
             assert.ifError(err);

From a4bd7cc91182abea73bb4570213afcc22bbcdf19 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Fri, 23 Dec 2022 12:46:45 -0500
Subject: [PATCH 09/18] docs: search by version in docs

---
 docs/js/search.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/js/search.js b/docs/js/search.js
index 71c623502e2..2d62ed66901 100644
--- a/docs/js/search.js
+++ b/docs/js/search.js
@@ -9,9 +9,12 @@ for (var i = 0; i < pairs.length; ++i) {
   }
 }
 
+var versionFromUrl = window.location.pathname.match(/^\/docs\/(\d+\.x)/);
+var version = versionFromUrl ? versionFromUrl[1] : '6.x';
+
 if (q != null) {
   document.getElementById('search-input').value = decodeURIComponent(q);
-  fetch(root + '/search?search=' + q).
+  fetch(root + '/search?search=' + q + '&version=' + version).
     then(function(res) { return res.json(); }).
     then(
       function(result) {

From c409b2c25584438a38e2498b2b100b89769b3a04 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sat, 24 Dec 2022 13:06:42 -0500
Subject: [PATCH 10/18] fix(discriminator): apply built-in plugins to
 discriminator schema even if `mergeHooks` and `mergePlugins` are both false

Fix #12696
---
 lib/helpers/model/discriminator.js        |  3 +++
 lib/helpers/schema/applyBuiltinPlugins.js | 12 ++++++++++
 lib/plugins/clearValidating.js            | 28 -----------------------
 lib/plugins/index.js                      |  7 ++++++
 test/model.discriminator.test.js          | 24 +++++++++++++++++++
 5 files changed, 46 insertions(+), 28 deletions(-)
 create mode 100644 lib/helpers/schema/applyBuiltinPlugins.js
 delete mode 100644 lib/plugins/clearValidating.js
 create mode 100644 lib/plugins/index.js

diff --git a/lib/helpers/model/discriminator.js b/lib/helpers/model/discriminator.js
index 96443002ab1..0c843df10da 100644
--- a/lib/helpers/model/discriminator.js
+++ b/lib/helpers/model/discriminator.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const Mixed = require('../../schema/mixed');
+const applyBuiltinPlugins = require('../schema/applyBuiltinPlugins');
 const defineKey = require('../document/compile').defineKey;
 const get = require('../get');
 const utils = require('../../utils');
@@ -40,6 +41,8 @@ module.exports = function discriminator(model, name, schema, tiedValue, applyPlu
     model.base._applyPlugins(schema, {
       skipTopLevel: !applyPluginsToDiscriminators
     });
+  } else if (!mergeHooks) {
+    applyBuiltinPlugins(schema);
   }
 
   const key = model.schema.options.discriminatorKey;
diff --git a/lib/helpers/schema/applyBuiltinPlugins.js b/lib/helpers/schema/applyBuiltinPlugins.js
new file mode 100644
index 00000000000..cbf999dd01d
--- /dev/null
+++ b/lib/helpers/schema/applyBuiltinPlugins.js
@@ -0,0 +1,12 @@
+'use strict';
+
+const builtinPlugins = require('../../plugins');
+
+module.exports = function applyBuiltinPlugins(schema) {
+  for (const plugin of Object.values(builtinPlugins)) {
+    plugin(schema, { deduplicate: true });
+  }
+  schema.plugins = Object.values(builtinPlugins).
+    map(fn => ({ fn, opts: { deduplicate: true } })).
+    concat(schema.plugins);
+};
\ No newline at end of file
diff --git a/lib/plugins/clearValidating.js b/lib/plugins/clearValidating.js
deleted file mode 100644
index 50264e33a6b..00000000000
--- a/lib/plugins/clearValidating.js
+++ /dev/null
@@ -1,28 +0,0 @@
-'use strict';
-
-/*!
- * ignore
- */
-
-module.exports = function clearValidating(schema) {
-  // `this.$__.validating` tracks whether there are multiple validations running
-  // in parallel. We need to clear `this.$__.validating` before post hooks for gh-8597
-  const unshift = true;
-  schema.s.hooks.post('validate', false, function clearValidatingPostValidate() {
-    if (this.$isSubdocument) {
-      return;
-    }
-
-    this.$__.validating = null;
-  }, unshift);
-
-  schema.s.hooks.post('validate', false, function clearValidatingPostValidateError(error, res, next) {
-    if (this.$isSubdocument) {
-      next();
-      return;
-    }
-
-    this.$__.validating = null;
-    next();
-  }, unshift);
-};
diff --git a/lib/plugins/index.js b/lib/plugins/index.js
new file mode 100644
index 00000000000..69fa6ad284c
--- /dev/null
+++ b/lib/plugins/index.js
@@ -0,0 +1,7 @@
+'use strict';
+
+exports.removeSubdocs = require('./removeSubdocs');
+exports.saveSubdocs = require('./saveSubdocs');
+exports.sharding = require('./sharding');
+exports.trackTransaction = require('./trackTransaction');
+exports.validateBeforeSave = require('./validateBeforeSave');
diff --git a/test/model.discriminator.test.js b/test/model.discriminator.test.js
index 3e34bfa7b62..a7eb5469a32 100644
--- a/test/model.discriminator.test.js
+++ b/test/model.discriminator.test.js
@@ -2077,4 +2077,28 @@ describe('model', function() {
       schema.pre('save', function testHook12604() {});
     }
   });
+
+  it('applies built-in plugins if mergePlugins and mergeHooks disabled (gh-12696) (gh-12604)', async function() {
+    const shapeDef = { name: String };
+    const shapeSchema = Schema(shapeDef, { discriminatorKey: 'kind' });
+
+    const Shape = db.model('Test', shapeSchema);
+
+    let subdocSaveCalls = 0;
+    const nestedSchema = Schema({ test: String });
+    nestedSchema.pre('save', function() {
+      ++subdocSaveCalls;
+    });
+
+    const squareSchema = Schema({ ...shapeDef, nested: nestedSchema });
+    const Square = Shape.discriminator(
+      'Square',
+      squareSchema,
+      { mergeHooks: false, mergePlugins: false }
+    );
+
+    assert.equal(subdocSaveCalls, 0);
+    await Square.create({ nested: { test: 'foo' } });
+    assert.equal(subdocSaveCalls, 1);
+  });
 });

From e64f652af89a086963797278d5957490b02f917d Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 26 Dec 2022 17:05:40 -0500
Subject: [PATCH 11/18] Update lib/helpers/schema/applyBuiltinPlugins.js

Co-authored-by: hasezoey <hasezoey@gmail.com>
---
 lib/helpers/schema/applyBuiltinPlugins.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/helpers/schema/applyBuiltinPlugins.js b/lib/helpers/schema/applyBuiltinPlugins.js
index cbf999dd01d..8bd7319cbb1 100644
--- a/lib/helpers/schema/applyBuiltinPlugins.js
+++ b/lib/helpers/schema/applyBuiltinPlugins.js
@@ -9,4 +9,4 @@ module.exports = function applyBuiltinPlugins(schema) {
   schema.plugins = Object.values(builtinPlugins).
     map(fn => ({ fn, opts: { deduplicate: true } })).
     concat(schema.plugins);
-};
\ No newline at end of file
+};

From ffefa87c895287826e3f39178b3f6e9492121e9e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 26 Dec 2022 17:09:28 -0500
Subject: [PATCH 12/18] refactor: use builtinPlugins list instead of importing
 all plugins

---
 lib/helpers/schema/applyBuiltinPlugins.js |  2 +-
 lib/index.js                              | 14 ++------------
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/lib/helpers/schema/applyBuiltinPlugins.js b/lib/helpers/schema/applyBuiltinPlugins.js
index cbf999dd01d..8bd7319cbb1 100644
--- a/lib/helpers/schema/applyBuiltinPlugins.js
+++ b/lib/helpers/schema/applyBuiltinPlugins.js
@@ -9,4 +9,4 @@ module.exports = function applyBuiltinPlugins(schema) {
   schema.plugins = Object.values(builtinPlugins).
     map(fn => ({ fn, opts: { deduplicate: true } })).
     concat(schema.plugins);
-};
\ No newline at end of file
+};
diff --git a/lib/index.js b/lib/index.js
index 0b76506cb0e..2109d3eec6d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -19,21 +19,17 @@ const Types = require('./types');
 const Query = require('./query');
 const Model = require('./model');
 const applyPlugins = require('./helpers/schema/applyPlugins');
+const builtinPlugins = require('./plugins');
 const driver = require('./driver');
 const promiseOrCallback = require('./helpers/promiseOrCallback');
 const legacyPluralize = require('./helpers/pluralize');
 const utils = require('./utils');
 const pkg = require('../package.json');
 const cast = require('./cast');
-const removeSubdocs = require('./plugins/removeSubdocs');
-const saveSubdocs = require('./plugins/saveSubdocs');
-const trackTransaction = require('./plugins/trackTransaction');
-const validateBeforeSave = require('./plugins/validateBeforeSave');
 
 const Aggregate = require('./aggregate');
 const PromiseProvider = require('./promise_provider');
 const printStrictQueryWarning = require('./helpers/printStrictQueryWarning');
-const shardingPlugin = require('./plugins/sharding');
 const trusted = require('./helpers/query/trusted').trusted;
 const sanitizeFilter = require('./helpers/query/sanitizeFilter');
 const isBsonType = require('./helpers/isBsonType');
@@ -108,13 +104,7 @@ function Mongoose(options) {
     configurable: false,
     enumerable: true,
     writable: false,
-    value: [
-      [saveSubdocs, { deduplicate: true }],
-      [validateBeforeSave, { deduplicate: true }],
-      [shardingPlugin, { deduplicate: true }],
-      [removeSubdocs, { deduplicate: true }],
-      [trackTransaction, { deduplicate: true }]
-    ]
+    value: Object.values(builtinPlugins).map(plugin => ([plugin, { deduplicate: true }]))
   });
 }
 

From 532b4521b257da72c04921ecf6e0db2b9c1a6adb Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 26 Dec 2022 17:32:25 -0500
Subject: [PATCH 13/18] docs: make not about strictNullChecks

---
 docs/typescript/schemas.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/typescript/schemas.md b/docs/typescript/schemas.md
index 80a86ed126d..6640427c8b9 100644
--- a/docs/typescript/schemas.md
+++ b/docs/typescript/schemas.md
@@ -62,7 +62,7 @@ const UserModel = mongoose.model('User', schema);
 
 There are a few caveats for using automatic type inference:
 
-1. You need to set `strict: true` in your `tsconfig.json` or `--strict` if running `tsc`. There are [known issues](https://github.com/Automattic/mongoose/issues/12420) with automatic type inference with strict mode disabled.
+1. You need to set `strictNullChecks: true` or `strict: true` in your `tsconfig.json`. Or, if you're setting flags at the command line, `--strictNullChecks` or `--strict`. There are [known issues](https://github.com/Automattic/mongoose/issues/12420) with automatic type inference with strict mode disabled.
 2. You need to define your schema in the `new Schema()` call. Don't assign your schema definition to a temporary variable. Doing something like `const schemaDefinition = { name: String }; const schema = new Schema(schemaDefinition);` will not work.
 
 If automatic type inference doesn't work for you, you can always fall back to document interface definitions.

From f140bf2c1d788528f2e8c54d52c12d643c9ecdfa Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 26 Dec 2022 17:43:48 -0500
Subject: [PATCH 14/18] test: try clearing models before and after

---
 test/model.validate.test.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/model.validate.test.js b/test/model.validate.test.js
index 877d83d90f0..30891867ff3 100644
--- a/test/model.validate.test.js
+++ b/test/model.validate.test.js
@@ -8,7 +8,8 @@ const mongoose = start.mongoose;
 const Schema = mongoose.Schema;
 
 describe('model: validate: ', function() {
-  afterEach(() => mongoose.deleteModel(/.*/));
+  beforeEach(() => mongoose.deleteModel(/.*/));
+  after(() => mongoose.deleteModel(/.*/));
 
   it('Model.validate() (gh-7587)', async function() {
     const Model = mongoose.model('Test', new Schema({

From fd1fa9d83d660adbebac1b2b1eedc57fbd85b39e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 27 Dec 2022 17:01:19 -0500
Subject: [PATCH 15/18] docs: backport #12830 to 5.x

---
 docs/js/search.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/js/search.js b/docs/js/search.js
index 71c623502e2..2d62ed66901 100644
--- a/docs/js/search.js
+++ b/docs/js/search.js
@@ -9,9 +9,12 @@ for (var i = 0; i < pairs.length; ++i) {
   }
 }
 
+var versionFromUrl = window.location.pathname.match(/^\/docs\/(\d+\.x)/);
+var version = versionFromUrl ? versionFromUrl[1] : '6.x';
+
 if (q != null) {
   document.getElementById('search-input').value = decodeURIComponent(q);
-  fetch(root + '/search?search=' + q).
+  fetch(root + '/search?search=' + q + '&version=' + version).
     then(function(res) { return res.json(); }).
     then(
       function(result) {

From c3384bcd1dc60fa15b57f41931bac9d9c99fc6e2 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 27 Dec 2022 17:19:21 -0500
Subject: [PATCH 16/18] docs: fix search re: #12830

---
 docs/js/navbar-search.js | 25 ++++++++++++++++---------
 docs/js/search.js        |  3 ++-
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/docs/js/navbar-search.js b/docs/js/navbar-search.js
index 94256ad730e..e80f5a4d48b 100644
--- a/docs/js/navbar-search.js
+++ b/docs/js/navbar-search.js
@@ -1,11 +1,18 @@
-document.getElementById('search-button-nav').onclick = function() {
-  var q = document.getElementById('search-input-nav').value;
-  window.location.href = 'search.html?q=' + encodeURIComponent(q);
-};
+(function() {
+  var versionFromUrl = window.location.pathname.match(/^\/docs\/(\d+\.x)/);
+  var version = versionFromUrl ? versionFromUrl[1] : defaultVersion;
 
-var q = document.getElementById('search-input-nav').onkeyup = function(ev) {
-  if (ev.keyCode === 13) {
+  var searchPrefix = versionFromUrl ? '/docs/' + version + '/docs/' : '/docs/';
+
+  document.getElementById('search-button-nav').onclick = function() {
     var q = document.getElementById('search-input-nav').value;
-    window.location.href = '/docs/search.html?q=' + encodeURIComponent(q);
-  }
-};
\ No newline at end of file
+    window.location.href = searchPrefix + 'search.html?q=' + encodeURIComponent(q);
+  };
+
+  document.getElementById('search-input-nav').onkeyup = function(ev) {
+    if (ev.keyCode === 13) {
+      var q = document.getElementById('search-input-nav').value;
+      window.location.href = searchPrefix + '/search.html?q=' + encodeURIComponent(q);
+    }
+  };
+})();
\ No newline at end of file
diff --git a/docs/js/search.js b/docs/js/search.js
index 2d62ed66901..dc7c33ea8fc 100644
--- a/docs/js/search.js
+++ b/docs/js/search.js
@@ -9,8 +9,9 @@ for (var i = 0; i < pairs.length; ++i) {
   }
 }
 
+var defaultVersion = '6.x';
 var versionFromUrl = window.location.pathname.match(/^\/docs\/(\d+\.x)/);
-var version = versionFromUrl ? versionFromUrl[1] : '6.x';
+var version = versionFromUrl ? versionFromUrl[1] : defaultVersion;
 
 if (q != null) {
   document.getElementById('search-input').value = decodeURIComponent(q);

From 48179b42b080712b572afd1aff3bd313937bcc92 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 27 Dec 2022 17:34:45 -0500
Subject: [PATCH 17/18] chore: search fixes

---
 docs/js/search.js | 2 +-
 docs/search.js    | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/docs/js/search.js b/docs/js/search.js
index dc7c33ea8fc..c3ad6cbcc96 100644
--- a/docs/js/search.js
+++ b/docs/js/search.js
@@ -26,7 +26,7 @@ if (q != null) {
         var html = '';
         for (var i = 0; i < result.results.length; ++i) {
           var res = result.results[i];
-          var url = res.url.replace(/^\//, '');
+          var url = res.url;
           html += '<li>' +
             '<a class="title" href="' + url + '">' +
             res.title +
diff --git a/docs/search.js b/docs/search.js
index ca18f2bae13..03de4f2f32d 100644
--- a/docs/search.js
+++ b/docs/search.js
@@ -122,7 +122,8 @@ async function run() {
   await Content.deleteMany({ version });
   for (const content of contents) {
     if (version !== '6.x') {
-      content.url = `/docs/${version}/docs${content.url}`;
+      const url = content.url.startsWith('/') ? content.url : `/${content.url}`;
+      content.url = `/docs/${version}/docs${url}`;
     }
     await content.save();
   }

From aef4c7bbefcc5cc44fc8e2ea51ef7030df86108a Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 27 Dec 2022 21:35:40 -0500
Subject: [PATCH 18/18] docs: quick fix for search re: #12830

---
 docs/search.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/docs/search.js b/docs/search.js
index 03de4f2f32d..08fef2d1424 100644
--- a/docs/search.js
+++ b/docs/search.js
@@ -121,7 +121,13 @@ async function run() {
 
   await Content.deleteMany({ version });
   for (const content of contents) {
-    if (version !== '6.x') {
+    if (version === '6.x') {
+      let url = content.url.startsWith('/') ? content.url : `/${content.url}`;
+      if (!url.startsWith('/docs')) {
+        url = '/docs'  + url;
+      }
+      content.url = url;
+    } else {
       const url = content.url.startsWith('/') ? content.url : `/${content.url}`;
       content.url = `/docs/${version}/docs${url}`;
     }