From b24696d51ccf6dc3e1ba786165bec9e1c994244c Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sat, 17 Aug 2024 14:58:12 -0400
Subject: [PATCH 01/10] feat: upgrade mongodb -> 6.8.0, handle throwing error
 on closed cursor in Mongoose

---
 lib/cursor/queryCursor.js | 5 +++++
 package.json              | 2 +-
 test/query.cursor.test.js | 3 ++-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/cursor/queryCursor.js b/lib/cursor/queryCursor.js
index 2c908de50d0..49359e40dfe 100644
--- a/lib/cursor/queryCursor.js
+++ b/lib/cursor/queryCursor.js
@@ -43,6 +43,7 @@ function QueryCursor(query) {
   this.cursor = null;
   this.skipped = false;
   this.query = query;
+  this._closeCalled = false;
   const model = query.model;
   this._mongooseOptions = {};
   this._transforms = [];
@@ -229,6 +230,7 @@ QueryCursor.prototype.close = async function close() {
   }
   try {
     await this.cursor.close();
+    this._closeCalled = true;
     this.emit('close');
   } catch (error) {
     this.listeners('error').length > 0 && this.emit('error', error);
@@ -266,6 +268,9 @@ QueryCursor.prototype.next = async function next() {
   if (typeof arguments[0] === 'function') {
     throw new MongooseError('QueryCursor.prototype.next() no longer accepts a callback');
   }
+  if (this._closeCalled) {
+    throw new MongooseError('Cannot call `next()` on a closed cursor');
+  }
   return new Promise((resolve, reject) => {
     _next(this, function(error, doc) {
       if (error) {
diff --git a/package.json b/package.json
index 013c7325c21..9c9097adc18 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   "dependencies": {
     "bson": "^6.7.0",
     "kareem": "2.6.3",
-    "mongodb": "6.7.0",
+    "mongodb": "6.8.0",
     "mpath": "0.9.0",
     "mquery": "5.0.0",
     "ms": "2.1.3",
diff --git a/test/query.cursor.test.js b/test/query.cursor.test.js
index a5f7afc2027..d80264c5f2d 100644
--- a/test/query.cursor.test.js
+++ b/test/query.cursor.test.js
@@ -415,7 +415,8 @@ describe('QueryCursor', function() {
         await cursor.next();
         assert.ok(false);
       } catch (error) {
-        assert.equal(error.name, 'MongoCursorExhaustedError');
+        assert.equal(error.name, 'MongooseError');
+        assert.ok(error.message.includes('closed cursor'), error.message);
       }
     });
   });

From 3bc8123bfab36d5ee528ce491362255d6c3b96a0 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Sat, 17 Aug 2024 15:03:43 -0400
Subject: [PATCH 02/10] rename closeCalled -> closed for more consistent
 semantics

---
 lib/cursor/queryCursor.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/cursor/queryCursor.js b/lib/cursor/queryCursor.js
index 49359e40dfe..6f00a316794 100644
--- a/lib/cursor/queryCursor.js
+++ b/lib/cursor/queryCursor.js
@@ -43,7 +43,7 @@ function QueryCursor(query) {
   this.cursor = null;
   this.skipped = false;
   this.query = query;
-  this._closeCalled = false;
+  this._closed = false;
   const model = query.model;
   this._mongooseOptions = {};
   this._transforms = [];
@@ -230,7 +230,7 @@ QueryCursor.prototype.close = async function close() {
   }
   try {
     await this.cursor.close();
-    this._closeCalled = true;
+    this._closed = true;
     this.emit('close');
   } catch (error) {
     this.listeners('error').length > 0 && this.emit('error', error);
@@ -268,7 +268,7 @@ QueryCursor.prototype.next = async function next() {
   if (typeof arguments[0] === 'function') {
     throw new MongooseError('QueryCursor.prototype.next() no longer accepts a callback');
   }
-  if (this._closeCalled) {
+  if (this._closed) {
     throw new MongooseError('Cannot call `next()` on a closed cursor');
   }
   return new Promise((resolve, reject) => {

From 91ebc9b8acb4d490e5147f6e0e38655ca9878f1e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 20 Aug 2024 16:18:35 -0400
Subject: [PATCH 03/10] fix(ChangeStream): rely on promises over events, make
 tests more durable

---
 lib/cursor/changeStream.js | 52 +++++++++++++++++++++++---------------
 test/connection.test.js    |  2 ++
 test/model.test.js         | 37 +++++++++++++++++++++------
 test/model.watch.test.js   |  5 ++--
 4 files changed, 65 insertions(+), 31 deletions(-)

diff --git a/lib/cursor/changeStream.js b/lib/cursor/changeStream.js
index ec5cac5705f..55cdecfcdc2 100644
--- a/lib/cursor/changeStream.js
+++ b/lib/cursor/changeStream.js
@@ -33,15 +33,18 @@ class ChangeStream extends EventEmitter {
       );
     }
 
-    // This wrapper is necessary because of buffering.
-    changeStreamThunk((err, driverChangeStream) => {
-      if (err != null) {
-        this.emit('error', err);
-        return;
-      }
+    this.$driverChangeStreamPromise = new Promise((resolve, reject) => {
+      // This wrapper is necessary because of buffering.
+      changeStreamThunk((err, driverChangeStream) => {
+        if (err != null) {
+          this.emit('error', err);
+          return reject(err);
+        }
 
-      this.driverChangeStream = driverChangeStream;
-      this.emit('ready');
+        this.driverChangeStream = driverChangeStream;
+        this.emit('ready');
+        resolve();
+      });
     });
   }
 
@@ -53,20 +56,23 @@ class ChangeStream extends EventEmitter {
     this.bindedEvents = true;
 
     if (this.driverChangeStream == null) {
-      this.once('ready', () => {
-        this.driverChangeStream.on('close', () => {
-          this.closed = true;
-        });
+      this.$driverChangeStreamPromise.then(
+        () => {
+          this.driverChangeStream.on('close', () => {
+            this.closed = true;
+          });
 
-        driverChangeStreamEvents.forEach(ev => {
-          this.driverChangeStream.on(ev, data => {
-            if (data != null && data.fullDocument != null && this.options && this.options.hydrate) {
-              data.fullDocument = this.options.model.hydrate(data.fullDocument);
-            }
-            this.emit(ev, data);
+          driverChangeStreamEvents.forEach(ev => {
+            this.driverChangeStream.on(ev, data => {
+              if (data != null && data.fullDocument != null && this.options && this.options.hydrate) {
+                data.fullDocument = this.options.model.hydrate(data.fullDocument);
+              }
+              this.emit(ev, data);
+            });
           });
-        });
-      });
+        },
+        () => {} // No need to register events if opening change stream failed
+      );
 
       return;
     }
@@ -142,8 +148,12 @@ class ChangeStream extends EventEmitter {
     this.closed = true;
     if (this.driverChangeStream) {
       return this.driverChangeStream.close();
+    } else {
+      return this.$driverChangeStreamPromise.then(
+        () => this.driverChangeStream.close(),
+        () => {} // No need to close if opening the change stream failed
+      );
     }
-    return Promise.resolve();
   }
 }
 
diff --git a/test/connection.test.js b/test/connection.test.js
index d395be5511b..03f87b40f3d 100644
--- a/test/connection.test.js
+++ b/test/connection.test.js
@@ -1032,6 +1032,8 @@ describe('connections:', function() {
     await nextChange;
     assert.equal(changes.length, 1);
     assert.equal(changes[0].operationType, 'insert');
+
+    await changeStream.close();
     await conn.close();
   });
 
diff --git a/test/model.test.js b/test/model.test.js
index b73757e4721..52d04a92b9a 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -7,6 +7,7 @@ const sinon = require('sinon');
 const start = require('./common');
 
 const assert = require('assert');
+const { once } = require('events');
 const random = require('./util').random;
 const util = require('./util');
 
@@ -3560,14 +3561,21 @@ describe('Model', function() {
         it('fullDocument (gh-11936)', async function() {
           const MyModel = db.model('Test', new Schema({ name: String }));
 
+          const doc = await MyModel.create({ name: 'Ned Stark' });
           const changeStream = await MyModel.watch([], {
             fullDocument: 'updateLookup',
             hydrate: true
           });
+          await changeStream.$driverChangeStreamPromise;
 
-          const doc = await MyModel.create({ name: 'Ned Stark' });
-
-          const p = changeStream.next();
+          const p = new Promise((resolve) => {
+            changeStream.once('change', change => {
+              resolve(change);
+            });
+          });
+          // Need to wait for resume token to be set after the event listener,
+          // otherwise change stream might not pick up the update.
+          await once(changeStream.driverChangeStream, 'resumeTokenChanged');
           await MyModel.updateOne({ _id: doc._id }, { name: 'Tony Stark' });
 
           const changeData = await p;
@@ -3576,6 +3584,8 @@ describe('Model', function() {
             doc._id.toHexString());
           assert.ok(changeData.fullDocument.$__);
           assert.equal(changeData.fullDocument.get('name'), 'Tony Stark');
+
+          await changeStream.close();
         });
 
         it('fullDocument with immediate watcher and hydrate (gh-14049)', async function() {
@@ -3583,15 +3593,22 @@ describe('Model', function() {
 
           const doc = await MyModel.create({ name: 'Ned Stark' });
 
+          let changeStream = null;
           const p = new Promise((resolve) => {
-            MyModel.watch([], {
+            changeStream = MyModel.watch([], {
               fullDocument: 'updateLookup',
               hydrate: true
-            }).on('change', change => {
+            });
+
+            changeStream.on('change', change => {
               resolve(change);
             });
           });
 
+          // Need to wait for cursor to be initialized and for resume token to
+          // be set, otherwise change stream might not pick up the update.
+          await changeStream.$driverChangeStreamPromise;
+          await once(changeStream.driverChangeStream, 'resumeTokenChanged');
           await MyModel.updateOne({ _id: doc._id }, { name: 'Tony Stark' });
 
           const changeData = await p;
@@ -3600,6 +3617,8 @@ describe('Model', function() {
             doc._id.toHexString());
           assert.ok(changeData.fullDocument.$__);
           assert.equal(changeData.fullDocument.get('name'), 'Tony Stark');
+
+          await changeStream.close();
         });
 
         it('respects discriminators (gh-11007)', async function() {
@@ -3654,11 +3673,12 @@ describe('Model', function() {
             setTimeout(resolve, 500, false);
           });
 
-          changeStream.close();
-          await db;
+          const close = changeStream.close();
+          await db.asPromise();
           const readyCalled = await ready;
           assert.strictEqual(readyCalled, false);
 
+          await close;
           await db.close();
         });
 
@@ -3675,10 +3695,11 @@ describe('Model', function() {
 
           await MyModel.create({ name: 'Hodor' });
 
-          changeStream.close();
+          const close = changeStream.close();
           const closedData = await closed;
           assert.strictEqual(closedData, true);
 
+          await close;
           await db.close();
         });
 
diff --git a/test/model.watch.test.js b/test/model.watch.test.js
index 84d41dc5b14..612bb84a75f 100644
--- a/test/model.watch.test.js
+++ b/test/model.watch.test.js
@@ -37,12 +37,13 @@ describe('model: watch: ', function() {
       const changeData = await changed;
       assert.equal(changeData.operationType, 'insert');
       assert.equal(changeData.fullDocument.name, 'Ned Stark');
+      await changeStream.close();
     });
 
     it('watch() close() prevents buffered watch op from running (gh-7022)', async function() {
       const MyModel = db.model('Test', new Schema({}));
       const changeStream = MyModel.watch();
-      const ready = new global.Promise(resolve => {
+      const ready = new Promise(resolve => {
         changeStream.once('data', () => {
           resolve(true);
         });
@@ -64,7 +65,7 @@ describe('model: watch: ', function() {
       await MyModel.init();
 
       const changeStream = MyModel.watch();
-      const closed = new global.Promise(resolve => {
+      const closed = new Promise(resolve => {
         changeStream.once('close', () => resolve(true));
       });
 

From 56f4adbd118f7f8a5f1d76f13fd16551e39689da Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 20 Aug 2024 16:23:27 -0400
Subject: [PATCH 04/10] bump max # of instantiations for now to fix tests

---
 scripts/tsc-diagnostics-check.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/tsc-diagnostics-check.js b/scripts/tsc-diagnostics-check.js
index 3e1f6c66282..c23da8c1f55 100644
--- a/scripts/tsc-diagnostics-check.js
+++ b/scripts/tsc-diagnostics-check.js
@@ -3,7 +3,7 @@
 const fs = require('fs');
 
 const stdin = fs.readFileSync(0).toString('utf8');
-const maxInstantiations = isNaN(process.argv[2]) ? 127500 : parseInt(process.argv[2], 10);
+const maxInstantiations = isNaN(process.argv[2]) ? 135000 : parseInt(process.argv[2], 10);
 
 console.log(stdin);
 

From a8bb7d6339062c6a90780876beb37156347adae2 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Tue, 20 Aug 2024 16:44:20 -0400
Subject: [PATCH 05/10] alternative approach to avoid change stream test
 failures

---
 lib/cursor/changeStream.js | 4 ++++
 test/model.test.js         | 3 +--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/cursor/changeStream.js b/lib/cursor/changeStream.js
index 55cdecfcdc2..dec8508d58f 100644
--- a/lib/cursor/changeStream.js
+++ b/lib/cursor/changeStream.js
@@ -86,6 +86,10 @@ class ChangeStream extends EventEmitter {
         if (data != null && data.fullDocument != null && this.options && this.options.hydrate) {
           data.fullDocument = this.options.model.hydrate(data.fullDocument);
         }
+        if (ev === 'error' && this.closed) {
+          // If we've already closed the stream, no need to emit further error events
+          return;
+        }
         this.emit(ev, data);
       });
     });
diff --git a/test/model.test.js b/test/model.test.js
index 52d04a92b9a..a84b874b669 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -3695,11 +3695,10 @@ describe('Model', function() {
 
           await MyModel.create({ name: 'Hodor' });
 
-          const close = changeStream.close();
+          changeStream.close();
           const closedData = await closed;
           assert.strictEqual(closedData, true);
 
-          await close;
           await db.close();
         });
 

From 1b5fecc64fa51750ec69c34d32f8c7f0b140f93c Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 21 Aug 2024 07:30:14 -0400
Subject: [PATCH 06/10] alternative fix for change stream tests re: #14177

---
 lib/cursor/changeStream.js | 4 ----
 test/model.test.js         | 7 +++++++
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/cursor/changeStream.js b/lib/cursor/changeStream.js
index dec8508d58f..55cdecfcdc2 100644
--- a/lib/cursor/changeStream.js
+++ b/lib/cursor/changeStream.js
@@ -86,10 +86,6 @@ class ChangeStream extends EventEmitter {
         if (data != null && data.fullDocument != null && this.options && this.options.hydrate) {
           data.fullDocument = this.options.model.hydrate(data.fullDocument);
         }
-        if (ev === 'error' && this.closed) {
-          // If we've already closed the stream, no need to emit further error events
-          return;
-        }
         this.emit(ev, data);
       });
     });
diff --git a/test/model.test.js b/test/model.test.js
index a84b874b669..e03cd5bd13b 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -3680,6 +3680,9 @@ describe('Model', function() {
 
           await close;
           await db.close();
+          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+          // may still poll after close.
+          changeStream.on('error', () => {});
         });
 
         it('watch() close() closes the stream (gh-7022)', async function() {
@@ -3700,6 +3703,10 @@ describe('Model', function() {
           assert.strictEqual(closedData, true);
 
           await db.close();
+
+          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+          // may still poll after close.
+          changeStream.on('error', () => {});
         });
 
         it('bubbles up resumeTokenChanged events (gh-14349)', async function() {

From e0d598423ea216605d3d29a11d451c6797864d68 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 21 Aug 2024 11:47:16 -0400
Subject: [PATCH 07/10] listen for error events on change stream to avoid
 change stream tests flaking

---
 test/model.watch.test.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/model.watch.test.js b/test/model.watch.test.js
index 612bb84a75f..099101e764f 100644
--- a/test/model.watch.test.js
+++ b/test/model.watch.test.js
@@ -56,6 +56,9 @@ describe('model: watch: ', function() {
       assert.strictEqual(readyCalled, false);
 
       await close;
+      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+      // may still poll after close.
+      changeStream.on('error', () => {});
     });
 
     it('watch() close() closes the stream (gh-7022)', async function() {
@@ -75,6 +78,9 @@ describe('model: watch: ', function() {
 
       const closedData = await closed;
       assert.strictEqual(closedData, true);
+      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+      // may still poll after close.
+      changeStream.on('error', () => {});
     });
   });
 });

From b08c93e5789ba5a0c3d5b12728c6bc9af1143ce6 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 21 Aug 2024 11:57:43 -0400
Subject: [PATCH 08/10] shuffle around error handler re: ChangeStream is closed
 errors

---
 test/model.test.js       |  8 ++++----
 test/model.watch.test.js | 13 +++++++------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/test/model.test.js b/test/model.test.js
index e03cd5bd13b..d2060fd9d00 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -3678,11 +3678,11 @@ describe('Model', function() {
           const readyCalled = await ready;
           assert.strictEqual(readyCalled, false);
 
-          await close;
-          await db.close();
           // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
           // may still poll after close.
           changeStream.on('error', () => {});
+          await close;
+          await db.close();
         });
 
         it('watch() close() closes the stream (gh-7022)', async function() {
@@ -3702,11 +3702,11 @@ describe('Model', function() {
           const closedData = await closed;
           assert.strictEqual(closedData, true);
 
-          await db.close();
-
           // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
           // may still poll after close.
           changeStream.on('error', () => {});
+
+          await db.close();
         });
 
         it('bubbles up resumeTokenChanged events (gh-14349)', async function() {
diff --git a/test/model.watch.test.js b/test/model.watch.test.js
index 099101e764f..3e2ad733a24 100644
--- a/test/model.watch.test.js
+++ b/test/model.watch.test.js
@@ -50,15 +50,15 @@ describe('model: watch: ', function() {
         setTimeout(resolve, 500, false);
       });
 
+      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+      // may still poll after close.
+      changeStream.on('error', () => {});
       const close = changeStream.close();
       await db.asPromise();
       const readyCalled = await ready;
       assert.strictEqual(readyCalled, false);
 
       await close;
-      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
-      // may still poll after close.
-      changeStream.on('error', () => {});
     });
 
     it('watch() close() closes the stream (gh-7022)', async function() {
@@ -74,13 +74,14 @@ describe('model: watch: ', function() {
 
       await MyModel.create({ name: 'Hodor' });
 
+      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+      // may still poll after close.
+      changeStream.on('error', () => {});
+
       await changeStream.close();
 
       const closedData = await closed;
       assert.strictEqual(closedData, true);
-      // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
-      // may still poll after close.
-      changeStream.on('error', () => {});
     });
   });
 });

From 8c6bb8b2ce3e4522d758a8fd99f715d164fb864e Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 21 Aug 2024 13:12:22 -0400
Subject: [PATCH 09/10] shuffle around some more error handlers

---
 test/model.test.js | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/test/model.test.js b/test/model.test.js
index d2060fd9d00..9524e2cdbe7 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -3673,14 +3673,15 @@ describe('Model', function() {
             setTimeout(resolve, 500, false);
           });
 
+          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+          // may still poll after close.
+          changeStream.on('error', () => {});
+
           const close = changeStream.close();
           await db.asPromise();
           const readyCalled = await ready;
           assert.strictEqual(readyCalled, false);
 
-          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
-          // may still poll after close.
-          changeStream.on('error', () => {});
           await close;
           await db.close();
         });
@@ -3698,14 +3699,14 @@ describe('Model', function() {
 
           await MyModel.create({ name: 'Hodor' });
 
-          changeStream.close();
-          const closedData = await closed;
-          assert.strictEqual(closedData, true);
-
           // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
           // may still poll after close.
           changeStream.on('error', () => {});
 
+          changeStream.close();
+          const closedData = await closed;
+          assert.strictEqual(closedData, true);
+
           await db.close();
         });
 

From a725a7565c03935d6788284dca016f37718b51dc Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Wed, 21 Aug 2024 13:21:26 -0400
Subject: [PATCH 10/10] add some more error handling to hopefully prevent
 flaking change stream tests

---
 test/model.test.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/model.test.js b/test/model.test.js
index 9524e2cdbe7..f2d88586e63 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -3509,6 +3509,9 @@ describe('Model', function() {
           }
           changeStream.removeListener('change', listener);
           listener = null;
+          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+          // may still poll after close.
+          changeStream.on('error', () => {});
           changeStream.close();
           changeStream = null;
         });
@@ -3658,6 +3661,9 @@ describe('Model', function() {
           assert.equal(changeData.operationType, 'insert');
           assert.equal(changeData.fullDocument.name, 'Ned Stark');
 
+          // Change stream may still emit "MongoAPIError: ChangeStream is closed" because change stream
+          // may still poll after close.
+          changeStream.on('error', () => {});
           await changeStream.close();
           await db.close();
         });