refactor(NODE-5742): add streaming responses support (mongodb#3944)

Co-authored-by: Durran Jordan <durran@gmail.com>

Author: nbbeeken

src/cmap/connection.ts

@@ -170,11 +170,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   lastHelloMS?: number;
   serverApi?: ServerApi;
   helloOk?: boolean;
-  commandAsync: (
-    ns: MongoDBNamespace,
-    cmd: Document,
-    options: CommandOptions | undefined
-  ) => Promise<Document>;
   /** @internal */
   authContext?: AuthContext;
 
@@ -217,15 +212,6 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
   constructor(stream: Stream, options: ConnectionOptions) {
     super();
 
-    this.commandAsync = promisify(
-      (
-        ns: MongoDBNamespace,
-        cmd: Document,
-        options: CommandOptions | undefined,
-        callback: Callback
-      ) => this.command(ns, cmd, options, callback as any)
-    );
-
     this.id = options.id;
     this.address = streamIdentifier(stream, options);
     this.socketTimeoutMS = options.socketTimeoutMS ?? 0;
@@ -262,6 +248,12 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     this[kMessageStream].pipe(this[kStream]);
   }
 
+  // This whole class is temporary,
+  // Need to move this to be defined on the prototype for spying.
+  async commandAsync(ns: MongoDBNamespace, cmd: Document, opt?: CommandOptions) {
+    return promisify(this.command.bind(this))(ns, cmd, opt);
+  }
+
   get description(): StreamDescription {
     return this[kDescription];
   }
@@ -791,7 +783,6 @@ export class ModernConnection extends TypedEventEmitter<ConnectionEvents> {
   lastHelloMS?: number;
   serverApi?: ServerApi;
   helloOk?: boolean;
-  commandAsync: ModernConnection['command'];
   /** @internal */
   authContext?: AuthContext;
 
@@ -831,8 +822,6 @@ export class ModernConnection extends TypedEventEmitter<ConnectionEvents> {
   constructor(stream: Stream, options: ConnectionOptions) {
     super();
 
-    this.commandAsync = this.command.bind(this);
-
     this.id = options.id;
     this.address = streamIdentifier(stream, options);
     this.socketTimeoutMS = options.socketTimeoutMS ?? 0;
@@ -852,6 +841,10 @@ export class ModernConnection extends TypedEventEmitter<ConnectionEvents> {
     this.socket.on('timeout', this.onTimeout.bind(this));
   }
 
+  async commandAsync(...args: Parameters<typeof this.command>) {
+    return this.command(...args);
+  }
+
   /** Indicates that the connection (including underlying TCP socket) has been closed. */
   get closed(): boolean {
     return this.controller.signal.aborted;
@@ -1036,62 +1029,68 @@ export class ModernConnection extends TypedEventEmitter<ConnectionEvents> {
     return message;
   }
 
-  private async sendCommand(
-    message: WriteProtocolMessageType,
-    options: CommandOptions
-  ): Promise<Document> {
-    const { signal } = this.controller;
-
-    signal.throwIfAborted();
+  private async *sendWire(message: WriteProtocolMessageType, options: CommandOptions) {
+    this.controller.signal.throwIfAborted();
 
     if (typeof options.socketTimeoutMS === 'number') {
       this.socket.setTimeout(options.socketTimeoutMS);
     } else if (this.socketTimeoutMS !== 0) {
       this.socket.setTimeout(this.socketTimeoutMS);
     }
 
-    let response;
     try {
       await writeCommand(this, message, {
         agreedCompressor: this.description.compressor ?? 'none',
         zlibCompressionLevel: this.description.zlibCompressionLevel,
-        signal
+        signal: this.controller.signal
       });
 
-      if (options.noResponse) return { ok: 1 };
+      // TODO(NODE-5770): Replace controller to avoid boundless 'abort' listeners
+      this.controller = new AbortController();
 
-      signal.throwIfAborted();
+      if (options.noResponse) {
+        yield { ok: 1 };
+        return;
+      }
 
-      response = await read(this, { signal });
-    } finally {
-      // TODO(NODE-5770): Replace controller to avoid boundless 'abort' listeners
-      if (!signal.aborted) this.controller = new AbortController();
-    }
+      this.controller.signal.throwIfAborted();
 
-    response.parse(options);
+      for await (const response of readMany(this, { signal: this.controller.signal })) {
+        this.socket.setTimeout(0);
+        response.parse(options);
 
-    const [document] = response.documents;
+        const [document] = response.documents;
 
-    if (!Buffer.isBuffer(document)) {
-      const { session } = options;
-      if (session) {
-        updateSessionFromResponse(session, document);
-      }
+        if (!Buffer.isBuffer(document)) {
+          const { session } = options;
+          if (session) {
+            updateSessionFromResponse(session, document);
+          }
 
-      if (document.$clusterTime) {
-        this[kClusterTime] = document.$clusterTime;
-        this.emit(Connection.CLUSTER_TIME_RECEIVED, document.$clusterTime);
+          if (document.$clusterTime) {
+            this[kClusterTime] = document.$clusterTime;
+            this.emit(Connection.CLUSTER_TIME_RECEIVED, document.$clusterTime);
+          }
+        }
+
+        // TODO(NODE-5770): Replace controller to avoid boundless 'abort' listeners
+        this.controller = new AbortController();
+
+        yield document;
+        this.controller.signal.throwIfAborted();
+
+        if (typeof options.socketTimeoutMS === 'number') {
+          this.socket.setTimeout(options.socketTimeoutMS);
+        } else if (this.socketTimeoutMS !== 0) {
+          this.socket.setTimeout(this.socketTimeoutMS);
+        }
       }
+    } finally {
+      this.socket.setTimeout(0);
     }
-
-    return document;
   }
 
-  async command(
-    ns: MongoDBNamespace,
-    command: Document,
-    options: CommandOptions = {}
-  ): Promise<Document> {
+  async *sendCommand(ns: MongoDBNamespace, command: Document, options: CommandOptions = {}) {
     const message = this.prepareCommand(ns.db, command, options);
 
     let started = 0;
@@ -1103,76 +1102,84 @@ export class ModernConnection extends TypedEventEmitter<ConnectionEvents> {
       );
     }
 
-    let document = null;
+    let document;
     try {
-      document = await this.sendCommand(message, options);
-    } catch (ioError) {
-      if (this.monitorCommands) {
-        this.emit(
-          ModernConnection.COMMAND_FAILED,
-          new CommandFailedEvent(this as unknown as Connection, message, ioError, started)
-        );
-      }
-      throw ioError;
-    }
+      this.controller.signal.throwIfAborted();
+      for await (document of this.sendWire(message, options)) {
+        if (!Buffer.isBuffer(document) && document.writeConcernError) {
+          throw new MongoWriteConcernError(document.writeConcernError, document);
+        }
 
-    if (document == null) {
-      const unexpected = new MongoUnexpectedServerResponseError(
-        'sendCommand did not throw and did not return a document'
-      );
-      if (this.monitorCommands) {
-        this.emit(
-          ModernConnection.COMMAND_FAILED,
-          new CommandFailedEvent(this as unknown as Connection, message, unexpected, started)
-        );
-      }
-      throw unexpected;
-    }
+        if (
+          !Buffer.isBuffer(document) &&
+          (document.ok === 0 || document.$err || document.errmsg || document.code)
+        ) {
+          throw new MongoServerError(document);
+        }
 
-    if (document.writeConcernError) {
-      const writeConcernError = new MongoWriteConcernError(document.writeConcernError, document);
-      if (this.monitorCommands) {
-        this.emit(
-          ModernConnection.COMMAND_SUCCEEDED,
-          new CommandSucceededEvent(this as unknown as Connection, message, document, started)
-        );
-      }
-      throw writeConcernError;
-    }
+        if (this.monitorCommands) {
+          this.emit(
+            ModernConnection.COMMAND_SUCCEEDED,
+            new CommandSucceededEvent(
+              this as unknown as Connection,
+              message,
+              options.noResponse ? undefined : document,
+              started
+            )
+          );
+        }
 
-    if (document.ok === 0 || document.$err || document.errmsg || document.code) {
-      const serverError = new MongoServerError(document);
+        yield document;
+        this.controller.signal.throwIfAborted();
+      }
+    } catch (error) {
       if (this.monitorCommands) {
-        this.emit(
-          ModernConnection.COMMAND_FAILED,
-          new CommandFailedEvent(this as unknown as Connection, message, serverError, started)
-        );
+        error.name === 'MongoWriteConcernError'
+          ? this.emit(
+              ModernConnection.COMMAND_SUCCEEDED,
+              new CommandSucceededEvent(
+                this as unknown as Connection,
+                message,
+                options.noResponse ? undefined : document,
+                started
+              )
+            )
+          : this.emit(
+              ModernConnection.COMMAND_FAILED,
+              new CommandFailedEvent(this as unknown as Connection, message, error, started)
+            );
       }
-      throw serverError;
+      throw error;
     }
+  }
 
-    if (this.monitorCommands) {
-      this.emit(
-        ModernConnection.COMMAND_SUCCEEDED,
-        new CommandSucceededEvent(
-          this as unknown as Connection,
-          message,
-          options.noResponse ? undefined : document,
-          started
-        )
-      );
+  async command(
+    ns: MongoDBNamespace,
+    command: Document,
+    options: CommandOptions = {}
+  ): Promise<Document> {
+    this.controller.signal.throwIfAborted();
+    for await (const document of this.sendCommand(ns, command, options)) {
+      return document;
     }
-
-    return document;
+    throw new MongoUnexpectedServerResponseError('Unable to get response from server');
   }
 
   exhaustCommand(
-    _ns: MongoDBNamespace,
-    _command: Document,
-    _options: CommandOptions,
-    _replyListener: Callback
+    ns: MongoDBNamespace,
+    command: Document,
+    options: CommandOptions,
+    replyListener: Callback
   ) {
-    throw new Error('NODE-5742: not implemented.');
+    const exhaustLoop = async () => {
+      this.controller.signal.throwIfAborted();
+      for await (const reply of this.sendCommand(ns, command, options)) {
+        replyListener(undefined, reply);
+        this.controller.signal.throwIfAborted();
+      }
+      throw new MongoUnexpectedServerResponseError('Server ended moreToCome unexpectedly');
+    };
+    exhaustLoop().catch(replyListener);
   }
 }
 

src/sdam/monitor.ts

@@ -2,7 +2,7 @@ import { clearTimeout, setTimeout } from 'timers';
 
 import { type Document, Long } from '../bson';
 import { connect } from '../cmap/connect';
-import { Connection, type ConnectionOptions } from '../cmap/connection';
+import type { Connection, ConnectionOptions } from '../cmap/connection';
 import { getFAASEnv } from '../cmap/handshake/client_metadata';
 import { LEGACY_HELLO_COMMAND } from '../constants';
 import { MongoError, MongoErrorLabel, MongoNetworkTimeoutError } from '../error';
@@ -132,9 +132,7 @@ export class Monitor extends TypedEventEmitter<MonitorEvents> {
       useBigInt64: false,
       promoteLongs: true,
       promoteValues: true,
-      promoteBuffers: true,
-      // TODO(NODE-5741): override monitors to use old connection
-      connectionType: Connection
+      promoteBuffers: true
     };
 
     // ensure no authentication is used for monitoring

test/integration/connection-monitoring-and-pooling/rtt_pinger.test.ts

@@ -164,7 +164,7 @@ describe('class RTTPinger', () => {
       const rttPingers = await getRTTPingers(client);
 
       for (const rtt of rttPingers) {
-        sinon.stub(rtt.connection, 'command').yieldsRight(new Error('any error'));
+        sinon.stub(rtt.connection, 'commandAsync').rejects(new Error('any error'));
       }
       const spies = rttPingers.map(rtt => sinon.spy(rtt.connection, 'destroy'));
 

test/integration/mongodb-handshake/mongodb-handshake.test.ts

@@ -5,6 +5,7 @@ import * as sinon from 'sinon';
 import {
   Connection,
   LEGACY_HELLO_COMMAND,
+  ModernConnection,
   MongoServerError,
   MongoServerSelectionError,
   OpMsgRequest,
@@ -19,20 +20,24 @@ describe('MongoDB Handshake', () => {
 
   context('when hello is too large', () => {
     before(() => {
-      sinon.stub(Connection.prototype, 'command').callsFake(function (ns, cmd, options, callback) {
-        // @ts-expect-error: sinon will place wrappedMethod there
-        const command = Connection.prototype.command.wrappedMethod.bind(this);
-
-        if (cmd.hello || cmd[LEGACY_HELLO_COMMAND]) {
-          return command(
-            ns,
-            { ...cmd, client: { driver: { name: 'a'.repeat(1000) } } },
-            options,
-            callback
-          );
-        }
-        return command(ns, cmd, options, callback);
-      });
+      const connectionType =
+        process.env.MONGODB_NEW_CONNECTION === 'true' ? ModernConnection : Connection;
+
+      sinon
+        .stub(connectionType.prototype, 'commandAsync')
+        .callsFake(async function (ns, cmd, options) {
+          // @ts-expect-error: sinon will place wrappedMethod there
+          const commandAsync = connectionType.prototype.commandAsync.wrappedMethod.bind(this);
+
+          if (cmd.hello || cmd[LEGACY_HELLO_COMMAND]) {
+            return commandAsync(
+              ns,
+              { ...cmd, client: { driver: { name: 'a'.repeat(1000) } } },
+              options
+            );
+          }
+          return commandAsync(ns, cmd, options);
+        });
     });
 
     after(() => sinon.restore());
@@ -53,7 +58,9 @@ describe('MongoDB Handshake', () => {
     let spy: Sinon.SinonSpy;
 
     before(() => {
-      spy = sinon.spy(Connection.prototype, 'command');
+      const connectionType =
+        process.env.MONGODB_NEW_CONNECTION === 'true' ? ModernConnection : Connection;
+      spy = sinon.spy(connectionType.prototype, 'commandAsync');
     });
 
     after(() => sinon.restore());