fix(NODE-6864): socket errors are not always converted to MongoNetworkErrors (#4473)

Co-authored-by: Bailey Pearson <[email protected]>

Author: nbbeeken

src/cmap/connection.ts

@@ -247,9 +247,9 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.lastUseTime = now();
 
     this.messageStream = this.socket
-      .on('error', this.onError.bind(this))
+      .on('error', this.onSocketError.bind(this))
       .pipe(new SizedMessageTransform({ connection: this }))
-      .on('error', this.onError.bind(this));
+      .on('error', this.onTransformError.bind(this));
     this.socket.on('close', this.onClose.bind(this));
     this.socket.on('timeout', this.onTimeout.bind(this));
 
@@ -304,6 +304,14 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this.lastUseTime = now();
   }
 
+  private onSocketError(cause: Error) {
+    this.onError(new MongoNetworkError(cause.message, { cause }));
+  }
+
+  private onTransformError(error: Error) {
+    this.onError(error);
+  }
+
   public onError(error: Error) {
     this.cleanup(error);
   }
@@ -769,7 +777,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     } finally {
       this.dataEvents = null;
       this.messageStream.pause();
-      this.throwIfAborted();
     }
   }
 }

test/integration/node-specific/convert_socket_errors.test.ts

@@ -0,0 +1,78 @@
+import { Duplex } from 'node:stream';
+
+import { expect } from 'chai';
+import * as sinon from 'sinon';
+
+import { Connection, type MongoClient, MongoNetworkError, ns } from '../../mongodb';
+import { clearFailPoint, configureFailPoint } from '../../tools/utils';
+
+describe('Socket Errors', () => {
+  describe('when a socket emits an error', () => {
+    it('command throws a MongoNetworkError', async () => {
+      const socket = new Duplex();
+      // @ts-expect-error: not a real socket
+      const connection = new Connection(socket, {});
+      const testError = new Error('blah');
+      socket.emit('error', testError);
+      const commandRes = connection.command(ns('a.b'), { ping: 1 }, {});
+
+      const error = await commandRes.catch(error => error);
+      expect(error).to.be.instanceOf(MongoNetworkError);
+      expect(error.cause).to.equal(testError);
+    });
+  });
+
+  describe('when the sized message stream emits an error', () => {
+    it('command throws the same error', async () => {
+      const socket = new Duplex();
+      // @ts-expect-error: not a real socket
+      const connection = new Connection(socket, {});
+      const testError = new Error('blah');
+      // @ts-expect-error: private field
+      connection.messageStream.emit('error', testError);
+      const commandRes = connection.command(ns('a.b'), { ping: 1 }, {});
+
+      const error = await commandRes.catch(error => error);
+      expect(error).to.equal(testError);
+    });
+  });
+
+  describe('when destroyed by failpoint', () => {
+    let client: MongoClient;
+    let collection;
+
+    const metadata: MongoDBMetadataUI = { requires: { mongodb: '>=4.4' } };
+
+    beforeEach(async function () {
+      if (!this.configuration.filters.NodeVersionFilter.filter({ metadata })) {
+        return;
+      }
+
+      await configureFailPoint(this.configuration, {
+        configureFailPoint: 'failCommand',
+        mode: 'alwaysOn',
+        data: {
+          appName: 'failInserts2',
+          failCommands: ['insert'],
+          closeConnection: true
+        }
+      });
+
+      client = this.configuration.newClient({}, { appName: 'failInserts2' });
+      await client.connect();
+      const db = client.db('closeConn');
+      collection = db.collection('closeConn');
+    });
+
+    afterEach(async function () {
+      sinon.restore();
+      await clearFailPoint(this.configuration);
+      await client.close();
+    });
+
+    it('throws a MongoNetworkError', metadata, async () => {
+      const error = await collection.insertOne({ name: 'test' }).catch(error => error);
+      expect(error, error.stack).to.be.instanceOf(MongoNetworkError);
+    });
+  });
+});

test/integration/node-specific/resource_clean_up.test.ts

@@ -107,7 +107,7 @@ describe('Driver Resources', () => {
       await sleep(10);
       const promiseCountAfter = v8.queryObjects(Promise, { format: 'count' });
 
-      expect(promiseCountAfter).to.be.within(promiseCountBefore - 5, promiseCountBefore + 5);
+      expect(promiseCountAfter).to.be.lessThan(promiseCountBefore + 5);
     });
   });
 });