From 413059787acb619bcfe7e2ea9244df6a2441a204 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 5 Dec 2022 16:11:50 -0500
Subject: [PATCH 01/36] fix(NODE-4834): Add calls to destroy kMessageStream

---
 src/cmap/connection.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 85f6000817..79a130e013 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -314,6 +314,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
       return;
     }
 
+    this[kMessageStream].destroy(error);
     this[kStream].destroy(error);
 
     this.closed = true;
@@ -330,6 +331,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     if (this.closed) {
       return;
     }
+    this[kMessageStream].destroy();
 
     this.closed = true;
 
@@ -348,6 +350,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     }
 
     this[kDelayedTimeoutId] = setTimeout(() => {
+      this[kMessageStream].destroy();
       this[kStream].destroy();
 
       this.closed = true;
@@ -467,6 +470,8 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
 
     this.removeAllListeners(Connection.PINNED);
     this.removeAllListeners(Connection.UNPINNED);
+    
+    this[kMessageStream].destroy();
 
     options = Object.assign({ force: false }, options);
     if (this[kStream] == null || this.destroyed) {

From 4c1023574a01718d10c36ee3b1a404bc2e905123 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 5 Dec 2022 16:13:45 -0500
Subject: [PATCH 02/36] test(NODE-4834): WIP - Start work on unit tests

---
 test/unit/cmap/connection.test.ts | 167 +++++++++++++++++++++++-------
 1 file changed, 132 insertions(+), 35 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 5c8d872bb8..5d7219fb8d 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -43,12 +43,12 @@ class FakeSocket extends EventEmitter {
   }
 }
 
-describe('new Connection()', function () {
+describe('new Connection()', function() {
   let server;
   after(() => mock.cleanup());
   before(() => mock.createServer().then(s => (server = s)));
 
-  it('should support fire-and-forget messages', function (done) {
+  it('should support fire-and-forget messages', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -77,7 +77,7 @@ describe('new Connection()', function () {
     });
   });
 
-  it('should destroy streams which time out', function (done) {
+  it('should destroy streams which time out', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -108,7 +108,7 @@ describe('new Connection()', function () {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function (done) {
+  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -137,7 +137,7 @@ describe('new Connection()', function () {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function (done) {
+  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function(done) {
     server.setMessageHandler(() => {
       // respond to no requests to trigger timeout event
     });
@@ -158,23 +158,23 @@ describe('new Connection()', function () {
     });
   });
 
-  describe('#onMessage', function () {
-    context('when the connection is a monitoring connection', function () {
+  describe('#onMessage', function() {
+    context('when the connection is a monitoring connection', function() {
       let queue: Map<number, OperationDescription>;
       let driverSocket: FakeSocket;
       let connection: Connection;
 
-      beforeEach(function () {
+      beforeEach(function() {
         driverSocket = sinon.spy(new FakeSocket());
       });
 
-      context('when multiple hellos exist on the stream', function () {
+      context('when multiple hellos exist on the stream', function() {
         let callbackSpy;
         const inputStream = new Readable();
         const document = { ok: 1 };
         const last = { isWritablePrimary: true };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
           const firstHello = generateOpMsgBuffer(document);
           const secondHello = generateOpMsgBuffer(document);
@@ -200,18 +200,18 @@ describe('new Connection()', function () {
           inputStream.push(null);
         });
 
-        it('calls the callback with the last hello document', async function () {
+        it('calls the callback with the last hello document', async function() {
           const messages = await once(connection, 'message');
           expect(messages[0].responseTo).to.equal(0);
           expect(callbackSpy).to.be.calledOnceWith(undefined, last);
         });
       });
 
-      context('when requestId/responseTo do not match', function () {
+      context('when requestId/responseTo do not match', function() {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -242,16 +242,16 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function () {
+        it('calls the operation description callback with the document', function() {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when requestId/reponseTo match', function () {
+      context('when requestId/reponseTo match', function() {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -282,15 +282,15 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function () {
+        it('calls the operation description callback with the document', function() {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when no operation description is in the queue', function () {
+      context('when no operation description is in the queue', function() {
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
           connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
           connection.isMonitoringConnection = true;
@@ -298,7 +298,7 @@ describe('new Connection()', function () {
           queue = connection[queueSymbol];
         });
 
-        it('does not error', function () {
+        it('does not error', function() {
           const msg = generateOpMsgBuffer(document);
           const msgHeader: MessageHeader = {
             length: msg.readInt32LE(0),
@@ -315,12 +315,12 @@ describe('new Connection()', function () {
         });
       });
 
-      context('when more than one operation description is in the queue', function () {
+      context('when more than one operation description is in the queue', function() {
         let spyOne;
         let spyTwo;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           spyOne = sinon.spy();
           spyTwo = sinon.spy();
 
@@ -357,7 +357,7 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls all operation description callbacks with an error', function () {
+        it('calls all operation description callbacks with an error', function() {
           expect(spyOne).to.be.calledOnce;
           expect(spyTwo).to.be.calledOnce;
           const errorOne = spyOne.firstCall.args[0];
@@ -389,7 +389,7 @@ describe('new Connection()', function () {
       connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
       const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
       kDelayedTimeoutId = getSymbolFrom(connection, 'delayedTimeoutId');
-      messageStream = connection[messageStreamSymbol];
+      messageStream = sinon.spy(connection[messageStreamSymbol]);
     });
 
     afterEach(() => {
@@ -433,14 +433,106 @@ describe('new Connection()', function () {
       expect(connection).to.have.property('closed', false);
       expect(connection).to.have.property(kDelayedTimeoutId, null);
     });
+
+    // TODO(NODE-4834): Ask if this test should go in the test above
+    it('should destroy message stream and socket', () => {
+      expect(connection).to.have.property(kDelayedTimeoutId, null);
+
+      driverSocket.emit('timeout');
+
+      clock.tick(1);
+
+      expect(connection.onTimeout).to.have.been.calledOnce;
+      expect(connection).to.have.property(kDelayedTimeoutId).that.is.instanceOf(NodeJSTimeoutClass);
+
+      expect(messageStream.destroy).to.have.been.calledOnce;
+      expect(driverSocket.destroy).to.have.been.calledOnce;
+    });
   });
 
-  describe('.hasSessionSupport', function () {
+  describe('onError()', () => {
+    let connection: sinon.SinonSpiedInstance<Connection>;
+    let clock: sinon.SinonFakeTimers;
+    let timerSandbox: sinon.SinonFakeTimers;
+    let driverSocket: sinon.SinonSpiedInstance<FakeSocket>;
+    let messageStream: MessageStream;
+    let kDelayedTimeoutId: symbol;
+    let NodeJSTimeoutClass: any;
+    beforeEach(() => {
+      timerSandbox = createTimerSandbox();
+      clock = sinon.useFakeTimers();
+
+      NodeJSTimeoutClass = setTimeout(() => null, 1).constructor;
+
+      driverSocket = sinon.spy(new FakeSocket());
+      // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
+      connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
+      const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
+      kDelayedTimeoutId = getSymbolFrom(connection, 'delayedTimeoutId');
+      messageStream = sinon.spy(connection[messageStreamSymbol]);
+    });
+
+    afterEach(() => {
+      timerSandbox.restore();
+      clock.restore();
+    });
+
+    it('should destroy message stream and socket', () => {
+      messageStream.emit('error');
+
+      clock.tick(1);
+
+      expect(connection.onError).to.have.been.calledOnce;
+
+      expect(messageStream.destroy).to.have.been.calledOnce;
+      expect(driverSocket.destroy).to.have.been.calledOnce;
+    })
+  });
+
+  describe('onClose()', () => {
+    let connection: sinon.SinonSpiedInstance<Connection>;
+    let clock: sinon.SinonFakeTimers;
+    let timerSandbox: sinon.SinonFakeTimers;
+    let driverSocket: sinon.SinonSpiedInstance<FakeSocket>;
+    let messageStream: MessageStream;
+    let kDelayedTimeoutId: symbol;
+    let NodeJSTimeoutClass: any;
+    beforeEach(() => {
+      timerSandbox = createTimerSandbox();
+      clock = sinon.useFakeTimers();
+
+      NodeJSTimeoutClass = setTimeout(() => null, 1).constructor;
+
+      driverSocket = sinon.spy(new FakeSocket());
+      // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
+      connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
+      const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
+      kDelayedTimeoutId = getSymbolFrom(connection, 'delayedTimeoutId');
+      messageStream = sinon.spy(connection[messageStreamSymbol]);
+    });
+
+    afterEach(() => {
+      timerSandbox.restore();
+      clock.restore();
+    });
+
+    it('should destroy message stream', () => {
+      driverSocket.emit('close');
+
+      clock.tick(1);
+
+      expect(connection.onClose).to.have.been.calledOnce;
+
+      expect(messageStream.destroy).to.have.been.calledOnce;
+    })
+  });
+
+  describe('.hasSessionSupport', function() {
     let connection;
     const stream = new Socket();
 
-    context('when logicalSessionTimeoutMinutes is present', function () {
-      beforeEach(function () {
+    context('when logicalSessionTimeoutMinutes is present', function() {
+      beforeEach(function() {
         const options = {
           ...connectionOptionsDefaults,
           hostAddress: server.hostAddress(),
@@ -449,14 +541,14 @@ describe('new Connection()', function () {
         connection = new Connection(stream, options);
       });
 
-      it('returns true', function () {
+      it('returns true', function() {
         expect(hasSessionSupport(connection)).to.be.true;
       });
     });
 
-    context('when logicalSessionTimeoutMinutes is not present', function () {
-      context('when in load balancing mode', function () {
-        beforeEach(function () {
+    context('when logicalSessionTimeoutMinutes is not present', function() {
+      context('when in load balancing mode', function() {
+        beforeEach(function() {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -465,13 +557,13 @@ describe('new Connection()', function () {
           connection = new Connection(stream, options);
         });
 
-        it('returns true', function () {
+        it('returns true', function() {
           expect(hasSessionSupport(connection)).to.be.true;
         });
       });
 
-      context('when not in load balancing mode', function () {
-        beforeEach(function () {
+      context('when not in load balancing mode', function() {
+        beforeEach(function() {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -480,10 +572,15 @@ describe('new Connection()', function () {
           connection = new Connection(stream, options);
         });
 
-        it('returns false', function () {
+        it('returns false', function() {
           expect(hasSessionSupport(connection)).to.be.false;
         });
       });
     });
   });
+
+  // TODO(NODE-4834): Implement me
+  describe('destroy()', () => {
+    it('should end tcp socket and destroy messageStream', () => { });
+  });
 });

From b341938f6fe492756f10eb3aa9017370e070d45e Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 14:37:10 -0500
Subject: [PATCH 03/36] fix(NODE-4834): Add guards to onError, onClose,
 onTimeout

---
 src/cmap/connection.ts | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 79a130e013..f7be6260b2 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -310,7 +310,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   }
 
   onError(error: Error) {
-    if (this.closed) {
+    if (this.closed || this.destroyed) {
       return;
     }
 
@@ -328,7 +328,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   }
 
   onClose() {
-    if (this.closed) {
+    if (this.closed || this.destroyed) {
       return;
     }
     this[kMessageStream].destroy();
@@ -345,7 +345,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   }
 
   onTimeout() {
-    if (this.closed) {
+    if (this.closed || this.destroyed) {
       return;
     }
 
@@ -493,12 +493,19 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
       return;
     }
 
-    this[kStream].end(() => {
+    if (this[kStream].destroyed) {
       this.destroyed = true;
       if (typeof callback === 'function') {
         callback();
       }
-    });
+    } else {
+      this[kStream].end(() => {
+        this.destroyed = true;
+        if (typeof callback === 'function') {
+          callback();
+        }
+      });
+    }
   }
 
   command(

From 032de2d529bf35560830a2bfbf958b3fdc82132f Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 14:39:09 -0500
Subject: [PATCH 04/36] test(NODE-4834): WIP progress on unit tests

---
 test/unit/cmap/connection.test.ts | 59 +++++++++++++++++++++++--------
 1 file changed, 45 insertions(+), 14 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 5d7219fb8d..83adbf6915 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -26,6 +26,7 @@ const connectionOptionsDefaults = {
 
 /** The absolute minimum socket API needed by Connection as of writing this test */
 class FakeSocket extends EventEmitter {
+  destroyed: boolean;
   address() {
     // is never called
   }
@@ -34,6 +35,11 @@ class FakeSocket extends EventEmitter {
   }
   destroy() {
     // is called, has no side effects
+    this.destroyed = true;
+  }
+  end(cb) {
+    cb();
+    // is called, 
   }
   get remoteAddress() {
     return 'iLoveJavaScript';
@@ -434,7 +440,6 @@ describe('new Connection()', function() {
       expect(connection).to.have.property(kDelayedTimeoutId, null);
     });
 
-    // TODO(NODE-4834): Ask if this test should go in the test above
     it('should destroy message stream and socket', () => {
       expect(connection).to.have.property(kDelayedTimeoutId, null);
 
@@ -461,14 +466,10 @@ describe('new Connection()', function() {
     beforeEach(() => {
       timerSandbox = createTimerSandbox();
       clock = sinon.useFakeTimers();
-
-      NodeJSTimeoutClass = setTimeout(() => null, 1).constructor;
-
       driverSocket = sinon.spy(new FakeSocket());
       // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
       connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
       const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
-      kDelayedTimeoutId = getSymbolFrom(connection, 'delayedTimeoutId');
       messageStream = sinon.spy(connection[messageStreamSymbol]);
     });
 
@@ -486,7 +487,17 @@ describe('new Connection()', function() {
 
       expect(messageStream.destroy).to.have.been.calledOnce;
       expect(driverSocket.destroy).to.have.been.calledOnce;
-    })
+    });
+
+    it.only('should not call stream.end after onClose, onTimeout, or onError', () => {
+      messageStream.emit('error');
+      clock.tick(1);
+      expect(connection.onError).to.have.been.calledOnce;
+      expect(driverSocket.destroy).to.have.been.calledOnce;
+      connection.destroy();
+      clock.tick(1);
+      expect(driverSocket.end).to.not.have.been.called;
+    });
   });
 
   describe('onClose()', () => {
@@ -495,19 +506,14 @@ describe('new Connection()', function() {
     let timerSandbox: sinon.SinonFakeTimers;
     let driverSocket: sinon.SinonSpiedInstance<FakeSocket>;
     let messageStream: MessageStream;
-    let kDelayedTimeoutId: symbol;
-    let NodeJSTimeoutClass: any;
     beforeEach(() => {
       timerSandbox = createTimerSandbox();
       clock = sinon.useFakeTimers();
 
-      NodeJSTimeoutClass = setTimeout(() => null, 1).constructor;
-
       driverSocket = sinon.spy(new FakeSocket());
       // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
       connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
       const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
-      kDelayedTimeoutId = getSymbolFrom(connection, 'delayedTimeoutId');
       messageStream = sinon.spy(connection[messageStreamSymbol]);
     });
 
@@ -522,9 +528,8 @@ describe('new Connection()', function() {
       clock.tick(1);
 
       expect(connection.onClose).to.have.been.calledOnce;
-
       expect(messageStream.destroy).to.have.been.calledOnce;
-    })
+    });
   });
 
   describe('.hasSessionSupport', function() {
@@ -581,6 +586,32 @@ describe('new Connection()', function() {
 
   // TODO(NODE-4834): Implement me
   describe('destroy()', () => {
-    it('should end tcp socket and destroy messageStream', () => { });
+    let connection: sinon.SinonSpiedInstance<Connection>;
+    let clock: sinon.SinonFakeTimers;
+    let timerSandbox: sinon.SinonFakeTimers;
+    let driverSocket: sinon.SinonSpiedInstance<FakeSocket>;
+    let messageStream: MessageStream;
+    beforeEach(() => {
+      timerSandbox = createTimerSandbox();
+      clock = sinon.useFakeTimers();
+
+      driverSocket = sinon.spy(new FakeSocket());
+      // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
+      connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
+      const messageStreamSymbol = getSymbolFrom(connection, 'messageStream');
+      messageStream = sinon.spy(connection[messageStreamSymbol]);
+    });
+
+    afterEach(() => {
+      timerSandbox.restore();
+      clock.restore();
+    });
+
+    it.only('should end tcp socket and destroy messageStream', () => {
+      connection.destroy({ force: true });
+      clock.tick(1);
+      expect(messageStream.destroy).to.have.been.calledOnce;
+      expect(driverSocket.destroy).to.have.been.calledOnce;
+    });
   });
 });

From f75e202b6c506f4f8aba724d35c8ca80d12775f6 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 14:53:46 -0500
Subject: [PATCH 05/36] style(NODE-4834): Revert style changes

---
 test/unit/cmap/connection.test.ts | 68 +++++++++++++++----------------
 1 file changed, 34 insertions(+), 34 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 83adbf6915..7c5a8d50fb 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -49,12 +49,12 @@ class FakeSocket extends EventEmitter {
   }
 }
 
-describe('new Connection()', function() {
+describe('new Connection()', function () {
   let server;
   after(() => mock.cleanup());
   before(() => mock.createServer().then(s => (server = s)));
 
-  it('should support fire-and-forget messages', function(done) {
+  it('should support fire-and-forget messages', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -83,7 +83,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should destroy streams which time out', function(done) {
+  it('should destroy streams which time out', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -114,7 +114,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function(done) {
+  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -143,7 +143,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function(done) {
+  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function (done) {
     server.setMessageHandler(() => {
       // respond to no requests to trigger timeout event
     });
@@ -164,23 +164,23 @@ describe('new Connection()', function() {
     });
   });
 
-  describe('#onMessage', function() {
-    context('when the connection is a monitoring connection', function() {
+  describe('#onMessage', function () {
+    context('when the connection is a monitoring connection', function () {
       let queue: Map<number, OperationDescription>;
       let driverSocket: FakeSocket;
       let connection: Connection;
 
-      beforeEach(function() {
+      beforeEach(function () {
         driverSocket = sinon.spy(new FakeSocket());
       });
 
-      context('when multiple hellos exist on the stream', function() {
+      context('when multiple hellos exist on the stream', function () {
         let callbackSpy;
         const inputStream = new Readable();
         const document = { ok: 1 };
         const last = { isWritablePrimary: true };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
           const firstHello = generateOpMsgBuffer(document);
           const secondHello = generateOpMsgBuffer(document);
@@ -206,18 +206,18 @@ describe('new Connection()', function() {
           inputStream.push(null);
         });
 
-        it('calls the callback with the last hello document', async function() {
+        it('calls the callback with the last hello document', async function () {
           const messages = await once(connection, 'message');
           expect(messages[0].responseTo).to.equal(0);
           expect(callbackSpy).to.be.calledOnceWith(undefined, last);
         });
       });
 
-      context('when requestId/responseTo do not match', function() {
+      context('when requestId/responseTo do not match', function () {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -248,16 +248,16 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function() {
+        it('calls the operation description callback with the document', function () {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when requestId/reponseTo match', function() {
+      context('when requestId/reponseTo match', function () {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -288,15 +288,15 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function() {
+        it('calls the operation description callback with the document', function () {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when no operation description is in the queue', function() {
+      context('when no operation description is in the queue', function () {
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
           connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
           connection.isMonitoringConnection = true;
@@ -304,7 +304,7 @@ describe('new Connection()', function() {
           queue = connection[queueSymbol];
         });
 
-        it('does not error', function() {
+        it('does not error', function () {
           const msg = generateOpMsgBuffer(document);
           const msgHeader: MessageHeader = {
             length: msg.readInt32LE(0),
@@ -321,12 +321,12 @@ describe('new Connection()', function() {
         });
       });
 
-      context('when more than one operation description is in the queue', function() {
+      context('when more than one operation description is in the queue', function () {
         let spyOne;
         let spyTwo;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           spyOne = sinon.spy();
           spyTwo = sinon.spy();
 
@@ -363,7 +363,7 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls all operation description callbacks with an error', function() {
+        it('calls all operation description callbacks with an error', function () {
           expect(spyOne).to.be.calledOnce;
           expect(spyTwo).to.be.calledOnce;
           const errorOne = spyOne.firstCall.args[0];
@@ -532,12 +532,12 @@ describe('new Connection()', function() {
     });
   });
 
-  describe('.hasSessionSupport', function() {
+  describe('.hasSessionSupport', function () {
     let connection;
     const stream = new Socket();
 
-    context('when logicalSessionTimeoutMinutes is present', function() {
-      beforeEach(function() {
+    context('when logicalSessionTimeoutMinutes is present', function () {
+      beforeEach(function () {
         const options = {
           ...connectionOptionsDefaults,
           hostAddress: server.hostAddress(),
@@ -546,14 +546,14 @@ describe('new Connection()', function() {
         connection = new Connection(stream, options);
       });
 
-      it('returns true', function() {
+      it('returns true', function () {
         expect(hasSessionSupport(connection)).to.be.true;
       });
     });
 
-    context('when logicalSessionTimeoutMinutes is not present', function() {
-      context('when in load balancing mode', function() {
-        beforeEach(function() {
+    context('when logicalSessionTimeoutMinutes is not present', function () {
+      context('when in load balancing mode', function () {
+        beforeEach(function () {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -562,13 +562,13 @@ describe('new Connection()', function() {
           connection = new Connection(stream, options);
         });
 
-        it('returns true', function() {
+        it('returns true', function () {
           expect(hasSessionSupport(connection)).to.be.true;
         });
       });
 
-      context('when not in load balancing mode', function() {
-        beforeEach(function() {
+      context('when not in load balancing mode', function () {
+        beforeEach(function () {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -577,7 +577,7 @@ describe('new Connection()', function() {
           connection = new Connection(stream, options);
         });
 
-        it('returns false', function() {
+        it('returns false', function () {
           expect(hasSessionSupport(connection)).to.be.false;
         });
       });

From 586c410f42079f09501882a9ca09f5d1fc55b701 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 14:57:29 -0500
Subject: [PATCH 06/36] test(NODE-4834): Remove unit test 'only' annotations

---
 test/unit/cmap/connection.test.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 7c5a8d50fb..77b02aa935 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -489,7 +489,7 @@ describe('new Connection()', function () {
       expect(driverSocket.destroy).to.have.been.calledOnce;
     });
 
-    it.only('should not call stream.end after onClose, onTimeout, or onError', () => {
+    it('should not call stream.end after onClose, onTimeout, or onError', () => {
       messageStream.emit('error');
       clock.tick(1);
       expect(connection.onError).to.have.been.calledOnce;
@@ -607,7 +607,7 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it.only('should end tcp socket and destroy messageStream', () => {
+    it('should end tcp socket and destroy messageStream', () => {
       connection.destroy({ force: true });
       clock.tick(1);
       expect(messageStream.destroy).to.have.been.calledOnce;

From 7a8d807b3c31e62b1c628ebc671a391b3c6cfc42 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 15:14:01 -0500
Subject: [PATCH 07/36] test(NODE-4834): move test to more appropriate position

---
 test/unit/cmap/connection.test.ts | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 77b02aa935..6366763429 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -39,7 +39,6 @@ class FakeSocket extends EventEmitter {
   }
   end(cb) {
     cb();
-    // is called, 
   }
   get remoteAddress() {
     return 'iLoveJavaScript';
@@ -489,15 +488,6 @@ describe('new Connection()', function () {
       expect(driverSocket.destroy).to.have.been.calledOnce;
     });
 
-    it('should not call stream.end after onClose, onTimeout, or onError', () => {
-      messageStream.emit('error');
-      clock.tick(1);
-      expect(connection.onError).to.have.been.calledOnce;
-      expect(driverSocket.destroy).to.have.been.calledOnce;
-      connection.destroy();
-      clock.tick(1);
-      expect(driverSocket.end).to.not.have.been.called;
-    });
   });
 
   describe('onClose()', () => {
@@ -608,10 +598,20 @@ describe('new Connection()', function () {
     });
 
     it('should end tcp socket and destroy messageStream', () => {
-      connection.destroy({ force: true });
+      connection.destroy();
       clock.tick(1);
       expect(messageStream.destroy).to.have.been.calledOnce;
+      expect(driverSocket.end).to.have.been.calledOnce;
+    });
+
+    it('should not call stream.end after onClose, onTimeout, or onError', () => {
+      messageStream.emit('error');
+      clock.tick(1);
+      expect(connection.onError).to.have.been.calledOnce;
       expect(driverSocket.destroy).to.have.been.calledOnce;
+      connection.destroy();
+      clock.tick(1);
+      expect(driverSocket.end).to.not.have.been.called;
     });
   });
 });

From 0c804a6b20bbaae6befc6c7f81ddb33967c7689a Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 15:21:35 -0500
Subject: [PATCH 08/36] style(NODE-4834): Remove todo comment

---
 test/unit/cmap/connection.test.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 6366763429..b5f56be018 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -574,7 +574,6 @@ describe('new Connection()', function () {
     });
   });
 
-  // TODO(NODE-4834): Implement me
   describe('destroy()', () => {
     let connection: sinon.SinonSpiedInstance<Connection>;
     let clock: sinon.SinonFakeTimers;

From 4e5a9bbe1a3516ef6c286f9120f829dc1d03c75a Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 15:35:54 -0500
Subject: [PATCH 09/36] docs(NODE-4834): Add tsdoc comments for clarification
 on closed and destroyed flags and on{Error,Timeout,Close} event handlers

---
 src/cmap/connection.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index f7be6260b2..3ee023ec17 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -170,7 +170,9 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   address: string;
   socketTimeoutMS: number;
   monitorCommands: boolean;
+  /** True when after of onClose, onError, or onTimeout was called */
   closed: boolean;
+  /** True only after destroy has been called */
   destroyed: boolean;
   lastHelloMS?: number;
   serverApi?: ServerApi;
@@ -309,6 +311,12 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this[kLastUseTime] = now();
   }
 
+  /**
+   * @remarks
+   * onError is called when an error is propagated up from the socket behind
+   * kStream to kMessageStream. This occurs prior to the closing of the socket,
+   * so the resource must be return to the operating system here.
+   */
   onError(error: Error) {
     if (this.closed || this.destroyed) {
       return;
@@ -327,6 +335,11 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.emit(Connection.CLOSE);
   }
 
+  /**
+   * @remarks
+   * onClose is called when the socket underlying kStream has been closed and
+   * the resource is returned to the operating system
+   */
   onClose() {
     if (this.closed || this.destroyed) {
       return;
@@ -344,6 +357,11 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.emit(Connection.CLOSE);
   }
 
+  /**
+   * @remarks
+   * onTimeout is called when the tcp socket underlying kStream times out. This
+   * occurs prior to the closing of the socket, so the resouce must be returned
+   * to the operating system here */
   onTimeout() {
     if (this.closed || this.destroyed) {
       return;

From 5ccb807e8a89c1cf13a7b7fe9abd1357b2b3ca81 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 6 Dec 2022 15:46:01 -0500
Subject: [PATCH 10/36] style(NODE-4834): Eslint fixes

---
 src/cmap/connection.ts            | 2 +-
 test/unit/cmap/connection.test.ts | 3 ---
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 3ee023ec17..ea7a110b0c 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -488,7 +488,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
 
     this.removeAllListeners(Connection.PINNED);
     this.removeAllListeners(Connection.UNPINNED);
-    
+
     this[kMessageStream].destroy();
 
     options = Object.assign({ force: false }, options);
diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index b5f56be018..3b7b4c78f2 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -460,8 +460,6 @@ describe('new Connection()', function () {
     let timerSandbox: sinon.SinonFakeTimers;
     let driverSocket: sinon.SinonSpiedInstance<FakeSocket>;
     let messageStream: MessageStream;
-    let kDelayedTimeoutId: symbol;
-    let NodeJSTimeoutClass: any;
     beforeEach(() => {
       timerSandbox = createTimerSandbox();
       clock = sinon.useFakeTimers();
@@ -487,7 +485,6 @@ describe('new Connection()', function () {
       expect(messageStream.destroy).to.have.been.calledOnce;
       expect(driverSocket.destroy).to.have.been.calledOnce;
     });
-
   });
 
   describe('onClose()', () => {

From 770d050c124c59972566e36f0f1369fc42d834d1 Mon Sep 17 00:00:00 2001
From: Warren James <28974128+W-A-James@users.noreply.github.com>
Date: Wed, 7 Dec 2022 09:27:39 -0500
Subject: [PATCH 11/36] test(NODE-4834): Change test descriptions to match
 testing standards and terminology used in spec

Co-authored-by: Durran Jordan <durran@gmail.com>
---
 test/unit/cmap/connection.test.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 3b7b4c78f2..63608690e2 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -439,7 +439,7 @@ describe('new Connection()', function () {
       expect(connection).to.have.property(kDelayedTimeoutId, null);
     });
 
-    it('should destroy message stream and socket', () => {
+    it('destroys the message stream and socket', () => {
       expect(connection).to.have.property(kDelayedTimeoutId, null);
 
       driverSocket.emit('timeout');
@@ -475,7 +475,7 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it('should destroy message stream and socket', () => {
+    it('destroys the message stream and socket', () => {
       messageStream.emit('error');
 
       clock.tick(1);
@@ -509,7 +509,7 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it('should destroy message stream', () => {
+    it('destroys the message stream', () => {
       driverSocket.emit('close');
 
       clock.tick(1);
@@ -593,14 +593,14 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it('should end tcp socket and destroy messageStream', () => {
+    it('ends the tcp socket and destroys the messageStream', () => {
       connection.destroy();
       clock.tick(1);
       expect(messageStream.destroy).to.have.been.calledOnce;
       expect(driverSocket.end).to.have.been.calledOnce;
     });
 
-    it('should not call stream.end after onClose, onTimeout, or onError', () => {
+    it('does not call stream.end after onClose, onTimeout, or onError', () => {
       messageStream.emit('error');
       clock.tick(1);
       expect(connection.onError).to.have.been.calledOnce;

From 92d577da6a1b63df0563fd5a29cc770c3673ed92 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Wed, 7 Dec 2022 11:06:08 -0500
Subject: [PATCH 12/36] docs(NODE-4834): Update inline documentation to
 reference state rather than explicit values

---
 src/cmap/connection.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index ea7a110b0c..8473243326 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -170,9 +170,9 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   address: string;
   socketTimeoutMS: number;
   monitorCommands: boolean;
-  /** True when after of onClose, onError, or onTimeout was called */
+  /** Indicates that the connection (including underlying TCP socket) has been closed. */
   closed: boolean;
-  /** True only after destroy has been called */
+  /** Indicates that the connection has been explicitly destroyed. In the destroyed state, the connection is also closed */
   destroyed: boolean;
   lastHelloMS?: number;
   serverApi?: ServerApi;

From 1ada8ca717c9367bfe525c49936feb82a23a759b Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 8 Dec 2022 10:28:43 -0500
Subject: [PATCH 13/36] fix(NODE-4834): Address review comments

---
 src/cmap/connection.ts | 31 +++++++++----------------------
 1 file changed, 9 insertions(+), 22 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 8473243326..469dfd93a1 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -122,8 +122,8 @@ export interface ProxyOptions {
 /** @public */
 export interface ConnectionOptions
   extends SupportedNodeConnectionOptions,
-    StreamDescriptionOptions,
-    ProxyOptions {
+  StreamDescriptionOptions,
+  ProxyOptions {
   // Internal creation info
   id: number | '<monitor>';
   generation: number;
@@ -360,7 +360,7 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   /**
    * @remarks
    * onTimeout is called when the tcp socket underlying kStream times out. This
-   * occurs prior to the closing of the socket, so the resouce must be returned
+   * occurs prior to the closing of the socket, so the resource must be returned
    * to the operating system here */
   onTimeout() {
     if (this.closed || this.destroyed) {
@@ -492,36 +492,23 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this[kMessageStream].destroy();
 
     options = Object.assign({ force: false }, options);
-    if (this[kStream] == null || this.destroyed) {
-      this.destroyed = true;
-      if (typeof callback === 'function') {
-        callback();
-      }
-
-      return;
+    if (this.destroyed) {
+      return callback?.();
     }
 
     if (options.force) {
       this[kStream].destroy();
       this.destroyed = true;
-      if (typeof callback === 'function') {
-        callback();
-      }
-
-      return;
+      return callback?.();
     }
 
-    if (this[kStream].destroyed) {
+    if (this[kStream].writableEnded) {
       this.destroyed = true;
-      if (typeof callback === 'function') {
-        callback();
-      }
+      return callback?.();
     } else {
       this[kStream].end(() => {
         this.destroyed = true;
-        if (typeof callback === 'function') {
-          callback();
-        }
+        callback?.();
       });
     }
   }

From 21dc8b48d5f2667647d4f5ad819d4f1a91ffc558 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 8 Dec 2022 10:33:54 -0500
Subject: [PATCH 14/36] test(NODE-4834): FakeSocket now simulates IO delay

---
 test/unit/cmap/connection.test.ts | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 63608690e2..d8ba1941c3 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -26,7 +26,7 @@ const connectionOptionsDefaults = {
 
 /** The absolute minimum socket API needed by Connection as of writing this test */
 class FakeSocket extends EventEmitter {
-  destroyed: boolean;
+  writableEnded: boolean;
   address() {
     // is never called
   }
@@ -35,10 +35,11 @@ class FakeSocket extends EventEmitter {
   }
   destroy() {
     // is called, has no side effects
-    this.destroyed = true;
+    this.writableEnded = true;
   }
   end(cb) {
-    cb();
+    // nextTick to simulate I/O delay
+    process.nextTick(cb);
   }
   get remoteAddress() {
     return 'iLoveJavaScript';

From f5f12f5aa62fbe3e6f5ceff5835df4c967c4d1c3 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 8 Dec 2022 10:38:25 -0500
Subject: [PATCH 15/36] style(NODE-4834): Revert unintended style change

---
 src/cmap/connection.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 469dfd93a1..48c7f9f2d0 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -122,8 +122,8 @@ export interface ProxyOptions {
 /** @public */
 export interface ConnectionOptions
   extends SupportedNodeConnectionOptions,
-  StreamDescriptionOptions,
-  ProxyOptions {
+    StreamDescriptionOptions,
+    ProxyOptions {
   // Internal creation info
   id: number | '<monitor>';
   generation: number;

From 1e5d874150488364eb75e255533577552677a4db Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 8 Dec 2022 11:18:19 -0500
Subject: [PATCH 16/36] test(NODE-4834): Ensure that FakeSocket.end also sets
 this.writableEnded to true

---
 test/unit/cmap/connection.test.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index d8ba1941c3..bed70177e7 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -38,6 +38,7 @@ class FakeSocket extends EventEmitter {
     this.writableEnded = true;
   }
   end(cb) {
+    this.writableEnded = true;
     // nextTick to simulate I/O delay
     process.nextTick(cb);
   }

From f9402811ca04cd4a7c6db124cf26c7d51acf5fdc Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 11:26:39 -0500
Subject: [PATCH 17/36] fix(NODE-4834): Update Connection.destroy and event
 handler logic to avoid race conditions on the this.closed flag

---
 src/cmap/connect.ts         |  2 +-
 src/cmap/connection.ts      | 53 +++++++++++--------------------------
 src/cmap/connection_pool.ts |  2 +-
 3 files changed, 17 insertions(+), 40 deletions(-)

diff --git a/src/cmap/connect.ts b/src/cmap/connect.ts
index fedf731132..0fc10c93e0 100644
--- a/src/cmap/connect.ts
+++ b/src/cmap/connect.ts
@@ -96,7 +96,7 @@ function performInitialHandshake(
 ) {
   const callback: Callback<Document> = function (err, ret) {
     if (err && conn) {
-      conn.destroy();
+      conn.destroy({ force: false });
     }
     _callback(err, ret);
   };
diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 48c7f9f2d0..e38a5120fb 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -122,8 +122,8 @@ export interface ProxyOptions {
 /** @public */
 export interface ConnectionOptions
   extends SupportedNodeConnectionOptions,
-    StreamDescriptionOptions,
-    ProxyOptions {
+  StreamDescriptionOptions,
+  ProxyOptions {
   // Internal creation info
   id: number | '<monitor>';
   generation: number;
@@ -149,7 +149,7 @@ export interface ConnectionOptions
 /** @public */
 export interface DestroyOptions {
   /** Force the destruction. */
-  force?: boolean;
+  force: boolean;
 }
 
 /** @public */
@@ -172,8 +172,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   monitorCommands: boolean;
   /** Indicates that the connection (including underlying TCP socket) has been closed. */
   closed: boolean;
-  /** Indicates that the connection has been explicitly destroyed. In the destroyed state, the connection is also closed */
-  destroyed: boolean;
   lastHelloMS?: number;
   serverApi?: ServerApi;
   helloOk?: boolean;
@@ -222,7 +220,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.monitorCommands = options.monitorCommands;
     this.serverApi = options.serverApi;
     this.closed = false;
-    this.destroyed = false;
     this[kHello] = null;
     this[kClusterTime] = null;
 
@@ -318,14 +315,10 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
    * so the resource must be return to the operating system here.
    */
   onError(error: Error) {
-    if (this.closed || this.destroyed) {
+    if (this.closed) {
       return;
     }
-
-    this[kMessageStream].destroy(error);
-    this[kStream].destroy(error);
-
-    this.closed = true;
+    this.destroy({ force: false });
 
     for (const op of this[kQueue].values()) {
       op.cb(error);
@@ -341,12 +334,10 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
    * the resource is returned to the operating system
    */
   onClose() {
-    if (this.closed || this.destroyed) {
+    if (this.closed) {
       return;
     }
-    this[kMessageStream].destroy();
-
-    this.closed = true;
+    this.destroy({ force: false });
 
     const message = `connection ${this.id} to ${this.address} closed`;
     for (const op of this[kQueue].values()) {
@@ -363,15 +354,12 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
    * occurs prior to the closing of the socket, so the resource must be returned
    * to the operating system here */
   onTimeout() {
-    if (this.closed || this.destroyed) {
+    if (this.closed) {
       return;
     }
 
     this[kDelayedTimeoutId] = setTimeout(() => {
-      this[kMessageStream].destroy();
-      this[kStream].destroy();
-
-      this.closed = true;
+      this.destroy({ force: false });
 
       const message = `connection ${this.id} to ${this.address} timed out`;
       const beforeHandshake = this.hello == null;
@@ -480,36 +468,25 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     callback(undefined, message.documents[0]);
   }
 
-  destroy(options?: DestroyOptions, callback?: Callback): void {
-    if (typeof options === 'function') {
-      callback = options;
-      options = { force: false };
-    }
-
+  destroy(options: DestroyOptions, callback?: Callback): void {
     this.removeAllListeners(Connection.PINNED);
     this.removeAllListeners(Connection.UNPINNED);
 
-    this[kMessageStream].destroy();
 
-    options = Object.assign({ force: false }, options);
-    if (this.destroyed) {
-      return callback?.();
-    }
+    this[kMessageStream].destroy();
+    this.closed = true;
 
     if (options.force) {
       this[kStream].destroy();
-      this.destroyed = true;
       return callback?.();
     }
 
-    if (this[kStream].writableEnded) {
-      this.destroyed = true;
-      return callback?.();
-    } else {
+    if (!this[kStream].writableEnded) {
       this[kStream].end(() => {
-        this.destroyed = true;
         callback?.();
       });
+    } else {
+      callback?.();
     }
   }
 
diff --git a/src/cmap/connection_pool.ts b/src/cmap/connection_pool.ts
index 5c8cbc9765..9827cf722f 100644
--- a/src/cmap/connection_pool.ts
+++ b/src/cmap/connection_pool.ts
@@ -591,7 +591,7 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
       new ConnectionClosedEvent(this, connection, reason)
     );
     // destroy the connection
-    process.nextTick(() => connection.destroy());
+    process.nextTick(() => connection.destroy({ force: false }));
   }
 
   private connectionIsStale(connection: Connection) {

From 927b8834aa1890a203d60c35c1b4171474a37d98 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 11:27:26 -0500
Subject: [PATCH 18/36] test(NODE-4834): Add unit tests to check that options
 are treated correctly in Connection.destroy

---
 test/unit/cmap/connection.test.ts | 115 +++++++++++++++++++-----------
 1 file changed, 72 insertions(+), 43 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index bed70177e7..fcfb3471e7 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -50,12 +50,24 @@ class FakeSocket extends EventEmitter {
   }
 }
 
-describe('new Connection()', function () {
+class InputStream extends Readable {
+  writableEnded: boolean;
+  constructor(options?) {
+    super(options);
+  }
+
+  end(cb) {
+    this.writableEnded = true;
+    process.nextTick(cb);
+  }
+}
+
+describe('new Connection()', function() {
   let server;
   after(() => mock.cleanup());
   before(() => mock.createServer().then(s => (server = s)));
 
-  it('should support fire-and-forget messages', function (done) {
+  it('should support fire-and-forget messages', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -84,7 +96,7 @@ describe('new Connection()', function () {
     });
   });
 
-  it('should destroy streams which time out', function (done) {
+  it('should destroy streams which time out', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -108,14 +120,14 @@ describe('new Connection()', function () {
         expect(err).to.be.instanceOf(MongoNetworkTimeoutError);
         expect(result).to.not.exist;
 
-        expect(conn).property('stream').property('destroyed', true);
+        expect(conn).property('stream').property('writableEnded', true);
 
         done();
       });
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function (done) {
+  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function(done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -144,7 +156,7 @@ describe('new Connection()', function () {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function (done) {
+  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function(done) {
     server.setMessageHandler(() => {
       // respond to no requests to trigger timeout event
     });
@@ -165,23 +177,23 @@ describe('new Connection()', function () {
     });
   });
 
-  describe('#onMessage', function () {
-    context('when the connection is a monitoring connection', function () {
+  describe('#onMessage', function() {
+    context('when the connection is a monitoring connection', function() {
       let queue: Map<number, OperationDescription>;
       let driverSocket: FakeSocket;
       let connection: Connection;
 
-      beforeEach(function () {
+      beforeEach(function() {
         driverSocket = sinon.spy(new FakeSocket());
       });
 
-      context('when multiple hellos exist on the stream', function () {
+      context('when multiple hellos exist on the stream', function() {
         let callbackSpy;
-        const inputStream = new Readable();
+        const inputStream = new InputStream();
         const document = { ok: 1 };
         const last = { isWritablePrimary: true };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
           const firstHello = generateOpMsgBuffer(document);
           const secondHello = generateOpMsgBuffer(document);
@@ -207,18 +219,18 @@ describe('new Connection()', function () {
           inputStream.push(null);
         });
 
-        it('calls the callback with the last hello document', async function () {
+        it('calls the callback with the last hello document', async function() {
           const messages = await once(connection, 'message');
           expect(messages[0].responseTo).to.equal(0);
           expect(callbackSpy).to.be.calledOnceWith(undefined, last);
         });
       });
 
-      context('when requestId/responseTo do not match', function () {
+      context('when requestId/responseTo do not match', function() {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -249,16 +261,16 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function () {
+        it('calls the operation description callback with the document', function() {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when requestId/reponseTo match', function () {
+      context('when requestId/reponseTo match', function() {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -289,15 +301,15 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function () {
+        it('calls the operation description callback with the document', function() {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when no operation description is in the queue', function () {
+      context('when no operation description is in the queue', function() {
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
           connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
           connection.isMonitoringConnection = true;
@@ -305,7 +317,7 @@ describe('new Connection()', function () {
           queue = connection[queueSymbol];
         });
 
-        it('does not error', function () {
+        it('does not error', function() {
           const msg = generateOpMsgBuffer(document);
           const msgHeader: MessageHeader = {
             length: msg.readInt32LE(0),
@@ -322,12 +334,12 @@ describe('new Connection()', function () {
         });
       });
 
-      context('when more than one operation description is in the queue', function () {
+      context('when more than one operation description is in the queue', function() {
         let spyOne;
         let spyTwo;
         const document = { ok: 1 };
 
-        beforeEach(function () {
+        beforeEach(function() {
           spyOne = sinon.spy();
           spyTwo = sinon.spy();
 
@@ -364,7 +376,7 @@ describe('new Connection()', function () {
           connection.onMessage(message);
         });
 
-        it('calls all operation description callbacks with an error', function () {
+        it('calls all operation description callbacks with an error', function() {
           expect(spyOne).to.be.calledOnce;
           expect(spyTwo).to.be.calledOnce;
           const errorOne = spyOne.firstCall.args[0];
@@ -409,13 +421,15 @@ describe('new Connection()', function () {
 
       driverSocket.emit('timeout');
       expect(connection.onTimeout).to.have.been.calledOnce;
+      expect(connection.destroy).to.not.have.been.called;
       expect(connection).to.have.property(kDelayedTimeoutId).that.is.instanceOf(NodeJSTimeoutClass);
       expect(connection).to.have.property('closed', false);
-      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.not.have.been.called;
 
       clock.tick(1);
 
-      expect(driverSocket.destroy).to.have.been.calledOnce;
+      expect(driverSocket.end).to.have.been.calledOnce;
+      expect(connection.destroy).to.have.been.calledOnce;
       expect(connection).to.have.property('closed', true);
     });
 
@@ -452,7 +466,7 @@ describe('new Connection()', function () {
       expect(connection).to.have.property(kDelayedTimeoutId).that.is.instanceOf(NodeJSTimeoutClass);
 
       expect(messageStream.destroy).to.have.been.calledOnce;
-      expect(driverSocket.destroy).to.have.been.calledOnce;
+      expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
 
@@ -485,7 +499,7 @@ describe('new Connection()', function () {
       expect(connection.onError).to.have.been.calledOnce;
 
       expect(messageStream.destroy).to.have.been.calledOnce;
-      expect(driverSocket.destroy).to.have.been.calledOnce;
+      expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
 
@@ -521,12 +535,12 @@ describe('new Connection()', function () {
     });
   });
 
-  describe('.hasSessionSupport', function () {
+  describe('.hasSessionSupport', function() {
     let connection;
     const stream = new Socket();
 
-    context('when logicalSessionTimeoutMinutes is present', function () {
-      beforeEach(function () {
+    context('when logicalSessionTimeoutMinutes is present', function() {
+      beforeEach(function() {
         const options = {
           ...connectionOptionsDefaults,
           hostAddress: server.hostAddress(),
@@ -535,14 +549,14 @@ describe('new Connection()', function () {
         connection = new Connection(stream, options);
       });
 
-      it('returns true', function () {
+      it('returns true', function() {
         expect(hasSessionSupport(connection)).to.be.true;
       });
     });
 
-    context('when logicalSessionTimeoutMinutes is not present', function () {
-      context('when in load balancing mode', function () {
-        beforeEach(function () {
+    context('when logicalSessionTimeoutMinutes is not present', function() {
+      context('when in load balancing mode', function() {
+        beforeEach(function() {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -551,13 +565,13 @@ describe('new Connection()', function () {
           connection = new Connection(stream, options);
         });
 
-        it('returns true', function () {
+        it('returns true', function() {
           expect(hasSessionSupport(connection)).to.be.true;
         });
       });
 
-      context('when not in load balancing mode', function () {
-        beforeEach(function () {
+      context('when not in load balancing mode', function() {
+        beforeEach(function() {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -566,7 +580,7 @@ describe('new Connection()', function () {
           connection = new Connection(stream, options);
         });
 
-        it('returns false', function () {
+        it('returns false', function() {
           expect(hasSessionSupport(connection)).to.be.false;
         });
       });
@@ -596,7 +610,7 @@ describe('new Connection()', function () {
     });
 
     it('ends the tcp socket and destroys the messageStream', () => {
-      connection.destroy();
+      connection.destroy({force: false});
       clock.tick(1);
       expect(messageStream.destroy).to.have.been.calledOnce;
       expect(driverSocket.end).to.have.been.calledOnce;
@@ -606,10 +620,25 @@ describe('new Connection()', function () {
       messageStream.emit('error');
       clock.tick(1);
       expect(connection.onError).to.have.been.calledOnce;
-      expect(driverSocket.destroy).to.have.been.calledOnce;
-      connection.destroy();
       clock.tick(1);
+      expect(driverSocket.destroy).to.not.have.been.calledOnce;
+      connection.destroy({force:false});
+      clock.tick(1);
+      expect(driverSocket.end).to.have.been.called;
+    });
+
+    it('does not call stream.end if options.force == true', () => {
+      connection.destroy({force:true});
+      clock.tick(1);
+      expect(driverSocket.destroy).to.have.been.calledOnce;
       expect(driverSocket.end).to.not.have.been.called;
     });
+
+    it('does not call stream.destroy if options.force == false', () => {
+      connection.destroy({force: false});
+      clock.tick(1);
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
+    });
   });
 });

From bf1c8f057ef2667d3665ef9089bd35e36c5d3333 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 11:46:04 -0500
Subject: [PATCH 19/36] fix(NODE-4834): Address eslint fixes

---
 src/cmap/connection.ts      | 5 ++---
 src/cmap/connection_pool.ts | 2 +-
 src/sdam/server.ts          | 5 ++++-
 src/sdam/topology.ts        | 6 +++---
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index e38a5120fb..f21df7e55f 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -122,8 +122,8 @@ export interface ProxyOptions {
 /** @public */
 export interface ConnectionOptions
   extends SupportedNodeConnectionOptions,
-  StreamDescriptionOptions,
-  ProxyOptions {
+    StreamDescriptionOptions,
+    ProxyOptions {
   // Internal creation info
   id: number | '<monitor>';
   generation: number;
@@ -472,7 +472,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.removeAllListeners(Connection.PINNED);
     this.removeAllListeners(Connection.UNPINNED);
 
-
     this[kMessageStream].destroy();
     this.closed = true;
 
diff --git a/src/cmap/connection_pool.ts b/src/cmap/connection_pool.ts
index 9827cf722f..d6e19a7e3d 100644
--- a/src/cmap/connection_pool.ts
+++ b/src/cmap/connection_pool.ts
@@ -515,7 +515,7 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
           ConnectionPool.CONNECTION_CLOSED,
           new ConnectionClosedEvent(this, conn, 'poolClosed')
         );
-        conn.destroy(options, cb);
+        conn.destroy({ force: !!options.force }, cb);
       },
       err => {
         this[kConnections].clear();
diff --git a/src/sdam/server.ts b/src/sdam/server.ts
index ae7a1fd5f6..9cd204ebf5 100644
--- a/src/sdam/server.ts
+++ b/src/sdam/server.ts
@@ -244,7 +244,10 @@ export class Server extends TypedEventEmitter<ServerEvents> {
 
   /** Destroy the server connection */
   destroy(options?: DestroyOptions, callback?: Callback): void {
-    if (typeof options === 'function') (callback = options), (options = {});
+    if (typeof options === 'function') {
+      callback = options;
+      options = { force: false };
+    }
     options = Object.assign({}, { force: false }, options);
 
     if (this.s.state === STATE_CLOSED) {
diff --git a/src/sdam/topology.ts b/src/sdam/topology.ts
index 601ae2c382..19b5af5484 100644
--- a/src/sdam/topology.ts
+++ b/src/sdam/topology.ts
@@ -496,14 +496,14 @@ export class Topology extends TypedEventEmitter<TopologyEvents> {
     if (typeof options === 'boolean') {
       options = { force: options };
     }
-    options = options ?? {};
+    options = options ?? { force: false };
 
     if (this.s.state === STATE_CLOSED || this.s.state === STATE_CLOSING) {
       return callback?.();
     }
 
     const destroyedServers = Array.from(this.s.servers.values(), server => {
-      return promisify(destroyServer)(server, this, options as CloseOptions);
+      return promisify(destroyServer)(server, this, Object.assign({ force: false }, options));
     });
 
     Promise.all(destroyedServers)
@@ -765,7 +765,7 @@ function destroyServer(
   options?: DestroyOptions,
   callback?: Callback
 ) {
-  options = options ?? {};
+  options = options ?? { force: false };
   for (const event of LOCAL_SERVER_EVENTS) {
     server.removeAllListeners(event);
   }

From 452c1f0f4edd6cf83ac254cd0e8e959a1cd39e8a Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 11:47:18 -0500
Subject: [PATCH 20/36] docs(NODE-4834): Remove irrelevant docs

---
 src/cmap/connection.ts | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index f21df7e55f..3d83d076e0 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -308,12 +308,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this[kLastUseTime] = now();
   }
 
-  /**
-   * @remarks
-   * onError is called when an error is propagated up from the socket behind
-   * kStream to kMessageStream. This occurs prior to the closing of the socket,
-   * so the resource must be return to the operating system here.
-   */
   onError(error: Error) {
     if (this.closed) {
       return;
@@ -328,11 +322,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.emit(Connection.CLOSE);
   }
 
-  /**
-   * @remarks
-   * onClose is called when the socket underlying kStream has been closed and
-   * the resource is returned to the operating system
-   */
   onClose() {
     if (this.closed) {
       return;
@@ -348,11 +337,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.emit(Connection.CLOSE);
   }
 
-  /**
-   * @remarks
-   * onTimeout is called when the tcp socket underlying kStream times out. This
-   * occurs prior to the closing of the socket, so the resource must be returned
-   * to the operating system here */
   onTimeout() {
     if (this.closed) {
       return;

From dcda86cb1c7f63a9dca18196a747e96535fd88bb Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 11:47:40 -0500
Subject: [PATCH 21/36] style(NODE-4834): eslint fixes

---
 test/unit/cmap/connection.test.ts | 76 +++++++++++++++----------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index fcfb3471e7..5f2ee16496 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -62,12 +62,12 @@ class InputStream extends Readable {
   }
 }
 
-describe('new Connection()', function() {
+describe('new Connection()', function () {
   let server;
   after(() => mock.cleanup());
   before(() => mock.createServer().then(s => (server = s)));
 
-  it('should support fire-and-forget messages', function(done) {
+  it('should support fire-and-forget messages', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -96,7 +96,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should destroy streams which time out', function(done) {
+  it('should destroy streams which time out', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -127,7 +127,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function(done) {
+  it('should throw a network error with kBeforeHandshake set to false on timeout after handshake', function (done) {
     server.setMessageHandler(request => {
       const doc = request.document;
       if (isHello(doc)) {
@@ -156,7 +156,7 @@ describe('new Connection()', function() {
     });
   });
 
-  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function(done) {
+  it('should throw a network error with kBeforeHandshake set to true on timeout before handshake', function (done) {
     server.setMessageHandler(() => {
       // respond to no requests to trigger timeout event
     });
@@ -177,23 +177,23 @@ describe('new Connection()', function() {
     });
   });
 
-  describe('#onMessage', function() {
-    context('when the connection is a monitoring connection', function() {
+  describe('#onMessage', function () {
+    context('when the connection is a monitoring connection', function () {
       let queue: Map<number, OperationDescription>;
       let driverSocket: FakeSocket;
       let connection: Connection;
 
-      beforeEach(function() {
+      beforeEach(function () {
         driverSocket = sinon.spy(new FakeSocket());
       });
 
-      context('when multiple hellos exist on the stream', function() {
+      context('when multiple hellos exist on the stream', function () {
         let callbackSpy;
         const inputStream = new InputStream();
         const document = { ok: 1 };
         const last = { isWritablePrimary: true };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
           const firstHello = generateOpMsgBuffer(document);
           const secondHello = generateOpMsgBuffer(document);
@@ -219,18 +219,18 @@ describe('new Connection()', function() {
           inputStream.push(null);
         });
 
-        it('calls the callback with the last hello document', async function() {
+        it('calls the callback with the last hello document', async function () {
           const messages = await once(connection, 'message');
           expect(messages[0].responseTo).to.equal(0);
           expect(callbackSpy).to.be.calledOnceWith(undefined, last);
         });
       });
 
-      context('when requestId/responseTo do not match', function() {
+      context('when requestId/responseTo do not match', function () {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -261,16 +261,16 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function() {
+        it('calls the operation description callback with the document', function () {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when requestId/reponseTo match', function() {
+      context('when requestId/reponseTo match', function () {
         let callbackSpy;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           callbackSpy = sinon.spy();
 
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
@@ -301,15 +301,15 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls the operation description callback with the document', function() {
+        it('calls the operation description callback with the document', function () {
           expect(callbackSpy).to.be.calledOnceWith(undefined, document);
         });
       });
 
-      context('when no operation description is in the queue', function() {
+      context('when no operation description is in the queue', function () {
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           // @ts-expect-error: driverSocket does not fully satisfy the stream type, but that's okay
           connection = sinon.spy(new Connection(driverSocket, connectionOptionsDefaults));
           connection.isMonitoringConnection = true;
@@ -317,7 +317,7 @@ describe('new Connection()', function() {
           queue = connection[queueSymbol];
         });
 
-        it('does not error', function() {
+        it('does not error', function () {
           const msg = generateOpMsgBuffer(document);
           const msgHeader: MessageHeader = {
             length: msg.readInt32LE(0),
@@ -334,12 +334,12 @@ describe('new Connection()', function() {
         });
       });
 
-      context('when more than one operation description is in the queue', function() {
+      context('when more than one operation description is in the queue', function () {
         let spyOne;
         let spyTwo;
         const document = { ok: 1 };
 
-        beforeEach(function() {
+        beforeEach(function () {
           spyOne = sinon.spy();
           spyTwo = sinon.spy();
 
@@ -376,7 +376,7 @@ describe('new Connection()', function() {
           connection.onMessage(message);
         });
 
-        it('calls all operation description callbacks with an error', function() {
+        it('calls all operation description callbacks with an error', function () {
           expect(spyOne).to.be.calledOnce;
           expect(spyTwo).to.be.calledOnce;
           const errorOne = spyOne.firstCall.args[0];
@@ -535,12 +535,12 @@ describe('new Connection()', function() {
     });
   });
 
-  describe('.hasSessionSupport', function() {
+  describe('.hasSessionSupport', function () {
     let connection;
     const stream = new Socket();
 
-    context('when logicalSessionTimeoutMinutes is present', function() {
-      beforeEach(function() {
+    context('when logicalSessionTimeoutMinutes is present', function () {
+      beforeEach(function () {
         const options = {
           ...connectionOptionsDefaults,
           hostAddress: server.hostAddress(),
@@ -549,14 +549,14 @@ describe('new Connection()', function() {
         connection = new Connection(stream, options);
       });
 
-      it('returns true', function() {
+      it('returns true', function () {
         expect(hasSessionSupport(connection)).to.be.true;
       });
     });
 
-    context('when logicalSessionTimeoutMinutes is not present', function() {
-      context('when in load balancing mode', function() {
-        beforeEach(function() {
+    context('when logicalSessionTimeoutMinutes is not present', function () {
+      context('when in load balancing mode', function () {
+        beforeEach(function () {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -565,13 +565,13 @@ describe('new Connection()', function() {
           connection = new Connection(stream, options);
         });
 
-        it('returns true', function() {
+        it('returns true', function () {
           expect(hasSessionSupport(connection)).to.be.true;
         });
       });
 
-      context('when not in load balancing mode', function() {
-        beforeEach(function() {
+      context('when not in load balancing mode', function () {
+        beforeEach(function () {
           const options = {
             ...connectionOptionsDefaults,
             hostAddress: server.hostAddress(),
@@ -580,7 +580,7 @@ describe('new Connection()', function() {
           connection = new Connection(stream, options);
         });
 
-        it('returns false', function() {
+        it('returns false', function () {
           expect(hasSessionSupport(connection)).to.be.false;
         });
       });
@@ -610,7 +610,7 @@ describe('new Connection()', function() {
     });
 
     it('ends the tcp socket and destroys the messageStream', () => {
-      connection.destroy({force: false});
+      connection.destroy({ force: false });
       clock.tick(1);
       expect(messageStream.destroy).to.have.been.calledOnce;
       expect(driverSocket.end).to.have.been.calledOnce;
@@ -622,20 +622,20 @@ describe('new Connection()', function() {
       expect(connection.onError).to.have.been.calledOnce;
       clock.tick(1);
       expect(driverSocket.destroy).to.not.have.been.calledOnce;
-      connection.destroy({force:false});
+      connection.destroy({ force: false });
       clock.tick(1);
       expect(driverSocket.end).to.have.been.called;
     });
 
     it('does not call stream.end if options.force == true', () => {
-      connection.destroy({force:true});
+      connection.destroy({ force: true });
       clock.tick(1);
       expect(driverSocket.destroy).to.have.been.calledOnce;
       expect(driverSocket.end).to.not.have.been.called;
     });
 
     it('does not call stream.destroy if options.force == false', () => {
-      connection.destroy({force: false});
+      connection.destroy({ force: false });
       clock.tick(1);
       expect(driverSocket.destroy).to.not.have.been.called;
       expect(driverSocket.end).to.have.been.calledOnce;

From c74bff8e239c6289166ac207b5e90e48940df5c6 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 14:08:45 -0500
Subject: [PATCH 22/36] refactor(NODE-4834): Make all paths through
 Connection.destroy async

---
 src/cmap/connection.ts | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 3d83d076e0..4bffacee74 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -458,18 +458,21 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
 
     this[kMessageStream].destroy();
     this.closed = true;
+    callback = callback
+      ? callback
+      : () => {
+          /* Ignore */
+        };
 
     if (options.force) {
       this[kStream].destroy();
-      return callback?.();
+      return process.nextTick(callback);
     }
 
     if (!this[kStream].writableEnded) {
-      this[kStream].end(() => {
-        callback?.();
-      });
+      this[kStream].end(callback);
     } else {
-      callback?.();
+      process.nextTick(callback);
     }
   }
 

From 7993c4ecd7d7c51a68b272d115f4e4a778503f1f Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 15:35:54 -0500
Subject: [PATCH 23/36] fix(NODE-4834): Address review comments

---
 src/cmap/connection.ts | 13 ++++++-------
 src/sdam/topology.ts   | 13 ++-----------
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/src/cmap/connection.ts b/src/cmap/connection.ts
index 4bffacee74..06ab8f396f 100644
--- a/src/cmap/connection.ts
+++ b/src/cmap/connection.ts
@@ -458,21 +458,20 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
 
     this[kMessageStream].destroy();
     this.closed = true;
-    callback = callback
-      ? callback
-      : () => {
-          /* Ignore */
-        };
 
     if (options.force) {
       this[kStream].destroy();
-      return process.nextTick(callback);
+      if (callback) {
+        return process.nextTick(callback);
+      }
     }
 
     if (!this[kStream].writableEnded) {
       this[kStream].end(callback);
     } else {
-      process.nextTick(callback);
+      if (callback) {
+        return process.nextTick(callback);
+      }
     }
   }
 
diff --git a/src/sdam/topology.ts b/src/sdam/topology.ts
index 19b5af5484..8850063c36 100644
--- a/src/sdam/topology.ts
+++ b/src/sdam/topology.ts
@@ -484,18 +484,9 @@ export class Topology extends TypedEventEmitter<TopologyEvents> {
   }
 
   /** Close this topology */
-  close(callback: Callback): void;
   close(options: CloseOptions): void;
   close(options: CloseOptions, callback: Callback): void;
-  close(options?: CloseOptions | Callback, callback?: Callback): void {
-    if (typeof options === 'function') {
-      callback = options;
-      options = {};
-    }
-
-    if (typeof options === 'boolean') {
-      options = { force: options };
-    }
+  close(options?: CloseOptions, callback?: Callback): void {
     options = options ?? { force: false };
 
     if (this.s.state === STATE_CLOSED || this.s.state === STATE_CLOSING) {
@@ -503,7 +494,7 @@ export class Topology extends TypedEventEmitter<TopologyEvents> {
     }
 
     const destroyedServers = Array.from(this.s.servers.values(), server => {
-      return promisify(destroyServer)(server, this, Object.assign({ force: false }, options));
+      return promisify(destroyServer)(server, this, { force: !!options?.force });
     });
 
     Promise.all(destroyedServers)

From e5c8e0af50834db48357ef2df1f3d5bb2c59d59a Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 16:08:48 -0500
Subject: [PATCH 24/36] test(NODE-4834): Update old test

---
 test/integration/crud/misc_cursors.test.js | 75 ++++++++--------------
 1 file changed, 26 insertions(+), 49 deletions(-)

diff --git a/test/integration/crud/misc_cursors.test.js b/test/integration/crud/misc_cursors.test.js
index ff3776ff35..392689cee8 100644
--- a/test/integration/crud/misc_cursors.test.js
+++ b/test/integration/crud/misc_cursors.test.js
@@ -13,6 +13,7 @@ const { ReadPreference } = require('../../../src/read_preference');
 const { ServerType } = require('../../../src/sdam/common');
 const { formatSort } = require('../../../src/sort');
 const { getSymbolFrom } = require('../../tools/utils');
+const { MongoExpiredSessionError } = require('../../../src/error');
 
 describe('Cursor', function () {
   before(function () {
@@ -1905,62 +1906,38 @@ describe('Cursor', function () {
     }
   });
 
-  it('should close dead tailable cursors', {
-    metadata: {
-      os: '!win32' // NODE-2943: timeout on windows
-    },
-
-    test: function (done) {
-      // http://www.mongodb.org/display/DOCS/Tailable+Cursors
-
-      const configuration = this.configuration;
-      client.connect((err, client) => {
-        expect(err).to.not.exist;
-        this.defer(() => client.close());
-
-        const db = client.db(configuration.db);
-        const options = { capped: true, size: 10000000 };
-        db.createCollection(
-          'test_if_dead_tailable_cursors_close',
-          options,
-          function (err, collection) {
-            expect(err).to.not.exist;
-
-            let closeCount = 0;
-            const docs = Array.from({ length: 100 }).map(() => ({ a: 1 }));
-            collection.insertMany(docs, { w: 'majority', wtimeoutMS: 5000 }, err => {
-              expect(err).to.not.exist;
+  it.only('closes cursors when client is closed even if it has not been exhausted', {
+      metadata: {
+        os: '!win32' // NODE-2943: timeout on windows
+      },
 
-              const cursor = collection.find({}, { tailable: true, awaitData: true });
-              const stream = cursor.stream();
+      async test() {
+        await client
+          .db()
+          .dropCollection('test_cleanup_tailable')
+          .catch(() => null);
 
-              stream.resume();
+        const collection = await client
+          .db()
+          .createCollection('test_cleanup_tailable', { capped: true, size: 1000, max: 3 });
 
-              var validator = () => {
-                closeCount++;
-                if (closeCount === 2) {
-                  done();
-                }
-              };
+        // insert only 2 docs in capped coll of 3
+        await collection.insertMany([{ a: 1 }, { a: 1 }]);
 
-              // we validate that the stream "ends" either cleanly or with an error
-              stream.on('end', validator);
-              stream.on('error', validator);
+        const cursor = collection.find({}, { tailable: true, awaitData: true, maxAwaitTimeMS: 2000 });
 
-              cursor.on('close', validator);
+        await cursor.next();
+        await cursor.next();
+        // will block for maxAwaitTimeMS (except we are closing the client)
+        const rejectedEarlyBecauseClientClosed = cursor.next().catch(error => error);
 
-              const docs = Array.from({ length: 100 }).map(() => ({ a: 1 }));
-              collection.insertMany(docs, err => {
-                expect(err).to.not.exist;
+        await client.close();
+        expect(cursor).to.have.property('killed', true);
 
-                setTimeout(() => client.close());
-              });
-            });
-          }
-        );
-      });
-    }
-  });
+        const error = await rejectedEarlyBecauseClientClosed;
+        expect(error).to.be.instanceOf(MongoExpiredSessionError);
+      }
+    });
 
   it('shouldAwaitData', {
     // Add a tag that our runner can trigger on

From 654019759ee80a44a98b071695d62a92efac46e9 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Mon, 12 Dec 2022 16:24:03 -0500
Subject: [PATCH 25/36] test(NODE-4834): remove 'only' annotation

---
 test/integration/crud/misc_cursors.test.js | 46 ++++++++++------------
 1 file changed, 20 insertions(+), 26 deletions(-)

diff --git a/test/integration/crud/misc_cursors.test.js b/test/integration/crud/misc_cursors.test.js
index 392689cee8..31db6d4de8 100644
--- a/test/integration/crud/misc_cursors.test.js
+++ b/test/integration/crud/misc_cursors.test.js
@@ -1906,38 +1906,32 @@ describe('Cursor', function () {
     }
   });
 
-  it.only('closes cursors when client is closed even if it has not been exhausted', {
-      metadata: {
-        os: '!win32' // NODE-2943: timeout on windows
-      },
+ it('closes cursors when client is closed even if it has not been exhausted', async function () {
+    await client
+      .db()
+      .dropCollection('test_cleanup_tailable')
+      .catch(() => null);
 
-      async test() {
-        await client
-          .db()
-          .dropCollection('test_cleanup_tailable')
-          .catch(() => null);
+    const collection = await client
+      .db()
+      .createCollection('test_cleanup_tailable', { capped: true, size: 1000, max: 3 });
 
-        const collection = await client
-          .db()
-          .createCollection('test_cleanup_tailable', { capped: true, size: 1000, max: 3 });
+    // insert only 2 docs in capped coll of 3
+    await collection.insertMany([{ a: 1 }, { a: 1 }]);
 
-        // insert only 2 docs in capped coll of 3
-        await collection.insertMany([{ a: 1 }, { a: 1 }]);
+    const cursor = collection.find({}, { tailable: true, awaitData: true, maxAwaitTimeMS: 2000 });
 
-        const cursor = collection.find({}, { tailable: true, awaitData: true, maxAwaitTimeMS: 2000 });
+    await cursor.next();
+    await cursor.next();
+    // will block for maxAwaitTimeMS (except we are closing the client)
+    const rejectedEarlyBecauseClientClosed = cursor.next().catch(error => error);
 
-        await cursor.next();
-        await cursor.next();
-        // will block for maxAwaitTimeMS (except we are closing the client)
-        const rejectedEarlyBecauseClientClosed = cursor.next().catch(error => error);
-
-        await client.close();
-        expect(cursor).to.have.property('killed', true);
+    await client.close();
+    expect(cursor).to.have.property('killed', true);
 
-        const error = await rejectedEarlyBecauseClientClosed;
-        expect(error).to.be.instanceOf(MongoExpiredSessionError);
-      }
-    });
+    const error = await rejectedEarlyBecauseClientClosed;
+    expect(error).to.be.instanceOf(MongoExpiredSessionError);
+  });
 
   it('shouldAwaitData', {
     // Add a tag that our runner can trigger on

From 7d43afbee4c41ad9d1e8f87f55b263fb97b0f48f Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 13 Dec 2022 12:59:27 -0500
Subject: [PATCH 26/36] test(NODE-4834): Fix failing tests

---
 test/integration/crud/misc_cursors.test.js     |  2 +-
 .../integration/node-specific/topology.test.js | 18 +++++++++++++-----
 ..._records_for_mongos_discovery.prose.test.ts |  2 +-
 .../assorted/server_selection_spec_helper.js   |  2 +-
 test/unit/error.test.ts                        |  2 +-
 test/unit/sdam/monitor.test.ts                 |  4 ++--
 test/unit/sdam/topology.test.js                | 18 +++++++++---------
 7 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/test/integration/crud/misc_cursors.test.js b/test/integration/crud/misc_cursors.test.js
index 31db6d4de8..87fd9187f1 100644
--- a/test/integration/crud/misc_cursors.test.js
+++ b/test/integration/crud/misc_cursors.test.js
@@ -1906,7 +1906,7 @@ describe('Cursor', function () {
     }
   });
 
- it('closes cursors when client is closed even if it has not been exhausted', async function () {
+  it('closes cursors when client is closed even if it has not been exhausted', async function () {
     await client
       .db()
       .dropCollection('test_cleanup_tailable')
diff --git a/test/integration/node-specific/topology.test.js b/test/integration/node-specific/topology.test.js
index ee806b9691..912c1443c4 100644
--- a/test/integration/node-specific/topology.test.js
+++ b/test/integration/node-specific/topology.test.js
@@ -10,12 +10,20 @@ describe('Topology', function () {
       const states = [];
       topology.on('stateChanged', (_, newState) => states.push(newState));
       topology.connect(err => {
-        expect(err).to.not.exist;
-        topology.close(err => {
+        try {
           expect(err).to.not.exist;
-          expect(topology.isDestroyed()).to.be.true;
-          expect(states).to.eql(['connecting', 'connected', 'closing', 'closed']);
-          done();
+        } catch (error) {
+          done(error);
+        }
+        topology.close({}, err => {
+          try {
+            expect(err).to.not.exist;
+            expect(topology.isDestroyed()).to.be.true;
+            expect(states).to.eql(['connecting', 'connected', 'closing', 'closed']);
+            done();
+          } catch (error) {
+            done(error);
+          }
         });
       });
     }
diff --git a/test/unit/assorted/polling_srv_records_for_mongos_discovery.prose.test.ts b/test/unit/assorted/polling_srv_records_for_mongos_discovery.prose.test.ts
index c96f738fa9..339f7c065b 100644
--- a/test/unit/assorted/polling_srv_records_for_mongos_discovery.prose.test.ts
+++ b/test/unit/assorted/polling_srv_records_for_mongos_discovery.prose.test.ts
@@ -97,7 +97,7 @@ describe('Polling Srv Records for Mongos Discovery', () => {
 
     afterEach(function (done) {
       if (context.topology) {
-        context.topology.close(done);
+        context.topology.close({}, done);
       } else {
         done();
       }
diff --git a/test/unit/assorted/server_selection_spec_helper.js b/test/unit/assorted/server_selection_spec_helper.js
index 3490ae9aac..724a8e4981 100644
--- a/test/unit/assorted/server_selection_spec_helper.js
+++ b/test/unit/assorted/server_selection_spec_helper.js
@@ -109,7 +109,7 @@ function executeServerSelectionTest(testDefinition, testDone) {
     });
 
   function done(err) {
-    topology.close(e => testDone(e || err));
+    topology.close({}, e => testDone(e || err));
   }
 
   topology.connect(err => {
diff --git a/test/unit/error.test.ts b/test/unit/error.test.ts
index 3ae43e35ea..14a624738f 100644
--- a/test/unit/error.test.ts
+++ b/test/unit/error.test.ts
@@ -379,7 +379,7 @@ describe('MongoErrors', () => {
 
       makeAndConnectReplSet((err, topology) => {
         // cleanup the server before calling done
-        const cleanup = err => topology.close(err2 => done(err || err2));
+        const cleanup = err => topology.close({}, err2 => done(err || err2));
 
         if (err) {
           return cleanup(err);
diff --git a/test/unit/sdam/monitor.test.ts b/test/unit/sdam/monitor.test.ts
index be7998d224..4bb611155d 100644
--- a/test/unit/sdam/monitor.test.ts
+++ b/test/unit/sdam/monitor.test.ts
@@ -52,7 +52,7 @@ describe('monitoring', function () {
         const serverDescription = Array.from(topology.description.servers.values())[0];
         expect(serverDescription).property('roundTripTime').to.be.greaterThan(0);
 
-        topology.close(done as any);
+        topology.close({}, done as any);
       }, 500);
     });
   }).skipReason = 'TODO(NODE-3819): Unskip flaky tests';
@@ -92,7 +92,7 @@ describe('monitoring', function () {
       const serverDescription = Array.from(topology.description.servers.values())[0];
       expect(serverDescription).property('roundTripTime').to.be.greaterThan(0);
 
-      topology.close(done);
+      topology.close({}, done);
     });
   }).skipReason = 'TODO(NODE-3600): Unskip flaky tests';
 
diff --git a/test/unit/sdam/topology.test.js b/test/unit/sdam/topology.test.js
index 978386697b..d3313010f3 100644
--- a/test/unit/sdam/topology.test.js
+++ b/test/unit/sdam/topology.test.js
@@ -26,7 +26,7 @@ describe('Topology (unit)', function () {
     }
 
     if (topology) {
-      topology.close();
+      topology.close({});
     }
   });
 
@@ -107,7 +107,7 @@ describe('Topology (unit)', function () {
 
       topology.connect(() => {
         expect(topology.shouldCheckForSessionSupport()).to.be.true;
-        topology.close(done);
+        topology.close({}, done);
       });
     });
 
@@ -127,7 +127,7 @@ describe('Topology (unit)', function () {
 
       topology.connect(() => {
         expect(topology.shouldCheckForSessionSupport()).to.be.false;
-        topology.close(done);
+        topology.close({}, done);
       });
     });
 
@@ -147,7 +147,7 @@ describe('Topology (unit)', function () {
 
       topology.connect(() => {
         expect(topology.shouldCheckForSessionSupport()).to.be.false;
-        topology.close(done);
+        topology.close({}, done);
       });
     });
   });
@@ -182,7 +182,7 @@ describe('Topology (unit)', function () {
             expect(err).to.exist;
             expect(err).to.match(/timed out/);
 
-            topology.close(done);
+            topology.close({}, done);
           });
         });
       });
@@ -325,7 +325,7 @@ describe('Topology (unit)', function () {
             expect(err).to.exist;
             expect(err).to.eql(serverDescription.error);
             expect(poolCleared).to.be.false;
-            topology.close(done);
+            topology.close({}, done);
           });
         });
       });
@@ -467,7 +467,7 @@ describe('Topology (unit)', function () {
 
         it('should clean up listeners on close', function (done) {
           topology.s.state = 'connected'; // fake state to test clean up logic
-          topology.close(e => {
+          topology.close({}, e => {
             const srvPollerListeners = topology.s.srvPoller.listeners(
               SrvPoller.SRV_RECORD_DISCOVERY
             );
@@ -547,7 +547,7 @@ describe('Topology (unit)', function () {
           // occurs `requestCheck` will be called for an immediate check.
           expect(requestCheck).property('callCount').to.equal(1);
 
-          topology.close(done);
+          topology.close({}, done);
         });
       });
     });
@@ -559,7 +559,7 @@ describe('Topology (unit)', function () {
         this.emit('connect');
       });
 
-      topology.close(() => {
+      topology.close({}, () => {
         topology.selectServer(ReadPreference.primary, { serverSelectionTimeoutMS: 2000 }, err => {
           expect(err).to.exist;
           expect(err).to.match(/Topology is closed/);

From 2cdcc21e3aab4b86215e77a52eba1d67c7415e89 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Tue, 13 Dec 2022 13:36:26 -0500
Subject: [PATCH 27/36] test(NODE-4834): remove debug messages

---
 test/integration/node-specific/topology.test.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/integration/node-specific/topology.test.js b/test/integration/node-specific/topology.test.js
index 912c1443c4..e8891db7bf 100644
--- a/test/integration/node-specific/topology.test.js
+++ b/test/integration/node-specific/topology.test.js
@@ -5,6 +5,7 @@ describe('Topology', function () {
   it('should correctly track states of a topology', {
     metadata: { requires: { apiVersion: false, topology: '!load-balanced' } }, // apiVersion not supported by newTopology()
     test: function (done) {
+      debugger;
       const topology = this.configuration.newTopology();
 
       const states = [];
@@ -15,7 +16,9 @@ describe('Topology', function () {
         } catch (error) {
           done(error);
         }
+        console.log('before close');
         topology.close({}, err => {
+          console.log('In close');
           try {
             expect(err).to.not.exist;
             expect(topology.isDestroyed()).to.be.true;

From 8d66f61e0c71dad71f37f4247e723dbed13766ce Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Tue, 13 Dec 2022 14:34:33 -0500
Subject: [PATCH 28/36] fix: only invoke callback when it is defined

---
 test/unit/cmap/connection.test.ts | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 5f2ee16496..8c6fe98ddc 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -40,7 +40,9 @@ class FakeSocket extends EventEmitter {
   end(cb) {
     this.writableEnded = true;
     // nextTick to simulate I/O delay
-    process.nextTick(cb);
+    if (typeof cb === 'function') {
+      process.nextTick(cb);
+    }
   }
   get remoteAddress() {
     return 'iLoveJavaScript';
@@ -58,7 +60,9 @@ class InputStream extends Readable {
 
   end(cb) {
     this.writableEnded = true;
-    process.nextTick(cb);
+    if (typeof cb === 'function') {
+      process.nextTick(cb);
+    }
   }
 }
 

From 44d5b05a38d4d0691c38e64b6ea871dfc15f3098 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Tue, 13 Dec 2022 15:14:54 -0500
Subject: [PATCH 29/36] fix: lint

---
 test/integration/node-specific/topology.test.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/integration/node-specific/topology.test.js b/test/integration/node-specific/topology.test.js
index e8891db7bf..72df055e42 100644
--- a/test/integration/node-specific/topology.test.js
+++ b/test/integration/node-specific/topology.test.js
@@ -5,7 +5,6 @@ describe('Topology', function () {
   it('should correctly track states of a topology', {
     metadata: { requires: { apiVersion: false, topology: '!load-balanced' } }, // apiVersion not supported by newTopology()
     test: function (done) {
-      debugger;
       const topology = this.configuration.newTopology();
 
       const states = [];

From 860d741a0ec27b13d9c2b949fa9842f176565c5b Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Tue, 13 Dec 2022 16:44:49 -0500
Subject: [PATCH 30/36] rm: prints

---
 test/integration/node-specific/topology.test.js | 2 --
 1 file changed, 2 deletions(-)

diff --git a/test/integration/node-specific/topology.test.js b/test/integration/node-specific/topology.test.js
index 72df055e42..912c1443c4 100644
--- a/test/integration/node-specific/topology.test.js
+++ b/test/integration/node-specific/topology.test.js
@@ -15,9 +15,7 @@ describe('Topology', function () {
         } catch (error) {
           done(error);
         }
-        console.log('before close');
         topology.close({}, err => {
-          console.log('In close');
           try {
             expect(err).to.not.exist;
             expect(topology.isDestroyed()).to.be.true;

From 3b59a122eeeb941b090709eb000f1110f66a4039 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 15 Dec 2022 16:04:24 -0500
Subject: [PATCH 31/36] test(NODE-4834): Update tests to be more coherent

---
 test/unit/cmap/connection.test.ts | 35 ++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 8c6fe98ddc..aeeb59947b 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -620,15 +620,44 @@ describe('new Connection()', function () {
       expect(driverSocket.end).to.have.been.calledOnce;
     });
 
-    it('does not call stream.end after onClose, onTimeout, or onError', () => {
+    it('calls stream.end exactly once when onError is called', () => {
       messageStream.emit('error');
       clock.tick(1);
       expect(connection.onError).to.have.been.calledOnce;
+      connection.destroy({ force: false });
+      clock.tick(1);
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
+    });
+
+    it('calls stream.end exactly once when onClose is called', () => {
+      driverSocket.emit('close');
+      clock.tick(1);
+      expect(connection.onClose).to.have.been.calledOnce;
+      connection.destroy({ force: false });
+      clock.tick(1);
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
+    });
+
+    it('calls stream.end exactly once when onTimeout is called', () => {
+      driverSocket.emit('timeout');
       clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.calledOnce;
+      expect(connection.onTimeout).to.have.been.calledOnce;
+      connection.destroy({ force: false });
+      clock.tick(1);
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
+    });
+
+    it('calls stream.end exactly once when destroy is called multiple times', () => {
+      connection.destroy({ force: false });
+      connection.destroy({ force: false });
+      connection.destroy({ force: false });
       connection.destroy({ force: false });
       clock.tick(1);
-      expect(driverSocket.end).to.have.been.called;
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
     });
 
     it('does not call stream.end if options.force == true', () => {

From 50fc706a115a140c20030d2152c681f145cc3640 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 15 Dec 2022 16:13:23 -0500
Subject: [PATCH 32/36] test(NODE-4834): Reorganize tests

---
 test/unit/cmap/connection.test.ts | 49 +++++++------------------------
 1 file changed, 11 insertions(+), 38 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index aeeb59947b..f32f148517 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -470,6 +470,7 @@ describe('new Connection()', function () {
       expect(connection).to.have.property(kDelayedTimeoutId).that.is.instanceOf(NodeJSTimeoutClass);
 
       expect(messageStream.destroy).to.have.been.calledOnce;
+      expect(driverSocket.destroy).to.not.have.been.calledOnce;
       expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
@@ -497,12 +498,12 @@ describe('new Connection()', function () {
 
     it('destroys the message stream and socket', () => {
       messageStream.emit('error');
-
       clock.tick(1);
-
       expect(connection.onError).to.have.been.calledOnce;
-
-      expect(messageStream.destroy).to.have.been.calledOnce;
+      connection.destroy({ force: false });
+      clock.tick(1);
+      expect(messageStream.destroy).to.not.have.been.calledOnce;
+      expect(driverSocket.destroy).to.not.have.been.called;
       expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
@@ -529,13 +530,15 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it('destroys the message stream', () => {
+    it('destroys the message stream and socket', () => {
       driverSocket.emit('close');
-
       clock.tick(1);
-
       expect(connection.onClose).to.have.been.calledOnce;
-      expect(messageStream.destroy).to.have.been.calledOnce;
+      connection.destroy({ force: false });
+      clock.tick(1);
+      expect(messageStream.destroy).to.not.have.been.calledOnce;
+      expect(driverSocket.destroy).to.not.have.been.called;
+      expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
 
@@ -620,36 +623,6 @@ describe('new Connection()', function () {
       expect(driverSocket.end).to.have.been.calledOnce;
     });
 
-    it('calls stream.end exactly once when onError is called', () => {
-      messageStream.emit('error');
-      clock.tick(1);
-      expect(connection.onError).to.have.been.calledOnce;
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.called;
-      expect(driverSocket.end).to.have.been.calledOnce;
-    });
-
-    it('calls stream.end exactly once when onClose is called', () => {
-      driverSocket.emit('close');
-      clock.tick(1);
-      expect(connection.onClose).to.have.been.calledOnce;
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.called;
-      expect(driverSocket.end).to.have.been.calledOnce;
-    });
-
-    it('calls stream.end exactly once when onTimeout is called', () => {
-      driverSocket.emit('timeout');
-      clock.tick(1);
-      expect(connection.onTimeout).to.have.been.calledOnce;
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.called;
-      expect(driverSocket.end).to.have.been.calledOnce;
-    });
-
     it('calls stream.end exactly once when destroy is called multiple times', () => {
       connection.destroy({ force: false });
       connection.destroy({ force: false });

From a11a4f6731e14290bd4b62966a8b9b5dd0e25acd Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Thu, 15 Dec 2022 16:38:51 -0500
Subject: [PATCH 33/36] test(NODE-4834): remove to.not.have.been.calledOnce
 instances

---
 test/unit/cmap/connection.test.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index f32f148517..e73e994041 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -470,7 +470,7 @@ describe('new Connection()', function () {
       expect(connection).to.have.property(kDelayedTimeoutId).that.is.instanceOf(NodeJSTimeoutClass);
 
       expect(messageStream.destroy).to.have.been.calledOnce;
-      expect(driverSocket.destroy).to.not.have.been.calledOnce;
+      expect(driverSocket.destroy).to.not.have.been.called;
       expect(driverSocket.end).to.have.been.calledOnce;
     });
   });
@@ -502,7 +502,7 @@ describe('new Connection()', function () {
       expect(connection.onError).to.have.been.calledOnce;
       connection.destroy({ force: false });
       clock.tick(1);
-      expect(messageStream.destroy).to.not.have.been.calledOnce;
+      expect(messageStream.destroy).to.have.been.called;
       expect(driverSocket.destroy).to.not.have.been.called;
       expect(driverSocket.end).to.have.been.calledOnce;
     });
@@ -536,7 +536,7 @@ describe('new Connection()', function () {
       expect(connection.onClose).to.have.been.calledOnce;
       connection.destroy({ force: false });
       clock.tick(1);
-      expect(messageStream.destroy).to.not.have.been.calledOnce;
+      expect(messageStream.destroy).to.have.been.called;
       expect(driverSocket.destroy).to.not.have.been.called;
       expect(driverSocket.end).to.have.been.calledOnce;
     });

From 23755ca7669c270fd29502838b0bf042b826839a Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Fri, 16 Dec 2022 09:47:31 -0500
Subject: [PATCH 34/36] test(NODE-4834): Separate tests more cleanly

---
 test/unit/cmap/connection.test.ts | 34 ++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index e73e994041..6319afece5 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -633,18 +633,32 @@ describe('new Connection()', function () {
       expect(driverSocket.end).to.have.been.calledOnce;
     });
 
-    it('does not call stream.end if options.force == true', () => {
-      connection.destroy({ force: true });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.have.been.calledOnce;
-      expect(driverSocket.end).to.not.have.been.called;
+    context('when options.force == true', function () {
+      it('calls steam.destroy', () => {
+        connection.destroy({ force: true });
+        clock.tick(1);
+        expect(driverSocket.destroy).to.have.been.calledOnce;
+      });
+
+      it('does not call stream.end', () => {
+        connection.destroy({ force: true });
+        clock.tick(1);
+        expect(driverSocket.end).to.not.have.been.called;
+      });
     });
 
-    it('does not call stream.destroy if options.force == false', () => {
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.called;
-      expect(driverSocket.end).to.have.been.calledOnce;
+    context('when options.force == false', function () {
+      it('calls stream.end', () => {
+        connection.destroy({ force: false });
+        clock.tick(1);
+        expect(driverSocket.end).to.have.been.calledOnce;
+      });
+
+      it('does not call stream.destroy', () => {
+        connection.destroy({ force: false });
+        clock.tick(1);
+        expect(driverSocket.destroy).to.not.have.been.called;
+      });
     });
   });
 });

From 878c7649311e938cdb05a93eac3b5b9c2e925409 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Fri, 16 Dec 2022 10:39:13 -0500
Subject: [PATCH 35/36] test(NODE-4834): Split up tests more cleanly

---
 test/unit/cmap/connection.test.ts | 58 ++++++++++++++++++++++---------
 1 file changed, 41 insertions(+), 17 deletions(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index 6319afece5..c9d34c0419 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -616,23 +616,6 @@ describe('new Connection()', function () {
       clock.restore();
     });
 
-    it('ends the tcp socket and destroys the messageStream', () => {
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(messageStream.destroy).to.have.been.calledOnce;
-      expect(driverSocket.end).to.have.been.calledOnce;
-    });
-
-    it('calls stream.end exactly once when destroy is called multiple times', () => {
-      connection.destroy({ force: false });
-      connection.destroy({ force: false });
-      connection.destroy({ force: false });
-      connection.destroy({ force: false });
-      clock.tick(1);
-      expect(driverSocket.destroy).to.not.have.been.called;
-      expect(driverSocket.end).to.have.been.calledOnce;
-    });
-
     context('when options.force == true', function () {
       it('calls steam.destroy', () => {
         connection.destroy({ force: true });
@@ -645,6 +628,26 @@ describe('new Connection()', function () {
         clock.tick(1);
         expect(driverSocket.end).to.not.have.been.called;
       });
+
+      it('destroys the tcp socket', () => {
+        connection.destroy({ force: true });
+        clock.tick(1);
+        expect(driverSocket.destroy).to.have.been.calledOnce;
+      });
+
+      it('destroys the messageStream', () => {
+        connection.destroy({ force: true });
+        clock.tick(1);
+        expect(messageStream.destroy).to.have.been.calledOnce;
+      });
+
+      it('calls stream.destroy whenever destroy is called ', () => {
+        connection.destroy({ force: true });
+        connection.destroy({ force: true });
+        connection.destroy({ force: true });
+        clock.tick(1);
+        expect(driverSocket.destroy).to.have.been.calledThrice;
+      });
     });
 
     context('when options.force == false', function () {
@@ -659,6 +662,27 @@ describe('new Connection()', function () {
         clock.tick(1);
         expect(driverSocket.destroy).to.not.have.been.called;
       });
+
+      it('ends the tcp socket', () => {
+        connection.destroy({ force: false });
+        clock.tick(1);
+        expect(driverSocket.end).to.have.been.calledOnce;
+      });
+
+      it('destroys the messageStream', () => {
+        connection.destroy({ force: false });
+        clock.tick(1);
+        expect(messageStream.destroy).to.have.been.calledOnce;
+      });
+
+      it('calls stream.end exactly once when destroy is called multiple times', () => {
+        connection.destroy({ force: false });
+        connection.destroy({ force: false });
+        connection.destroy({ force: false });
+        connection.destroy({ force: false });
+        clock.tick(1);
+        expect(driverSocket.end).to.have.been.calledOnce;
+      });
     });
   });
 });

From 995700b661d1ebafc907e2b473325fb60a32abd3 Mon Sep 17 00:00:00 2001
From: Warren James <warren.james@mongodb.com>
Date: Fri, 16 Dec 2022 10:50:18 -0500
Subject: [PATCH 36/36] test(NODE-4834): fix test name typo

---
 test/unit/cmap/connection.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/unit/cmap/connection.test.ts b/test/unit/cmap/connection.test.ts
index c9d34c0419..b29bf3a2e9 100644
--- a/test/unit/cmap/connection.test.ts
+++ b/test/unit/cmap/connection.test.ts
@@ -617,7 +617,7 @@ describe('new Connection()', function () {
     });
 
     context('when options.force == true', function () {
-      it('calls steam.destroy', () => {
+      it('calls stream.destroy', () => {
         connection.destroy({ force: true });
         clock.tick(1);
         expect(driverSocket.destroy).to.have.been.calledOnce;