Fix #1181 Add port property to installerOptions in the HTTPReceiver

src/App.spec.ts

@@ -51,6 +51,82 @@ function createDummyReceiverEvent(type: string = 'dummy_event_type'): ReceiverEv
 
 describe('App', () => {
   describe('constructor', () => {
+    describe('with a custom port value in HTTP Mode', () => {
+      const fakeBotId = 'B_FAKE_BOT_ID';
+      const fakeBotUserId = 'U_FAKE_BOT_USER_ID';
+      const overrides = mergeOverrides(
+        withNoopAppMetadata(),
+        withSuccessfulBotUserFetchingWebClient(fakeBotId, fakeBotUserId),
+      );
+      it('should accept a port value at the top-level', async () => {
+        // Arrange
+        const MockApp = await importApp(overrides);
+        // Act
+        const app = new MockApp({ token: '', signingSecret: '', port: 9999 });
+        // Assert
+        assert.equal((app as any).receiver.port, 9999);
+      });
+      it('should accept a port value under installerOptions', async () => {
+        // Arrange
+        const MockApp = await importApp(overrides);
+        // Act
+        const app = new MockApp({ token: '', signingSecret: '', port: 7777, installerOptions: { port: 9999 } });
+        // Assert
+        assert.equal((app as any).receiver.port, 9999);
+      });
+    });
+
+    describe('with a custom port value in Socket Mode', () => {
+      const fakeBotId = 'B_FAKE_BOT_ID';
+      const fakeBotUserId = 'U_FAKE_BOT_USER_ID';
+      const installationStore = {
+        storeInstallation: async () => { },
+        fetchInstallation: async () => { throw new Error('Failed fetching installation'); },
+        deleteInstallation: async () => { },
+      };
+      const overrides = mergeOverrides(
+        withNoopAppMetadata(),
+        withSuccessfulBotUserFetchingWebClient(fakeBotId, fakeBotUserId),
+      );
+      it('should accept a port value at the top-level', async () => {
+        // Arrange
+        const MockApp = await importApp(overrides);
+        // Act
+        const app = new MockApp({
+          socketMode: true,
+          appToken: '',
+          port: 9999,
+          clientId: '',
+          clientSecret: '',
+          stateSecret: '',
+          installerOptions: {
+          },
+          installationStore,
+        });
+        // Assert
+        assert.equal((app as any).receiver.httpServerPort, 9999);
+      });
+      it('should accept a port value under installerOptions', async () => {
+        // Arrange
+        const MockApp = await importApp(overrides);
+        // Act
+        const app = new MockApp({
+          socketMode: true,
+          appToken: '',
+          port: 7777,
+          clientId: '',
+          clientSecret: '',
+          stateSecret: '',
+          installerOptions: {
+            port: 9999,
+          },
+          installationStore,
+        });
+        // Assert
+        assert.equal((app as any).receiver.httpServerPort, 9999);
+      });
+    });
+
     // TODO: test when the single team authorization results fail. that should still succeed but warn. it also means
     // that the `ignoreSelf` middleware will fail (or maybe just warn) a bunch.
     describe('with successful single team authorization results', () => {

src/App.ts

@@ -78,6 +78,7 @@ const tokenUsage = 'Apps used in one workspace should be initialized with a toke
 export interface AppOptions {
   signingSecret?: HTTPReceiverOptions['signingSecret'];
   endpoints?: HTTPReceiverOptions['endpoints'];
+  port?: HTTPReceiverOptions['port'];
   customRoutes?: HTTPReceiverOptions['customRoutes'];
   processBeforeResponse?: HTTPReceiverOptions['processBeforeResponse'];
   signatureVerification?: HTTPReceiverOptions['signatureVerification'];
@@ -240,6 +241,7 @@ export default class App {
   public constructor({
     signingSecret = undefined,
     endpoints = undefined,
+    port = undefined,
     customRoutes = undefined,
     agent = undefined,
     clientTls = undefined,
@@ -337,6 +339,11 @@ export default class App {
       clientOptions: this.clientOptions,
       ...installerOptions,
     };
+    if (socketMode && port !== undefined && this.installerOptions.port === undefined) {
+      // As SocketModeReceiver uses a custom port number to listen on only for the OAuth flow,
+      // only installerOptions.port is available in the constructor arguments.
+      this.installerOptions.port = port;
+    }
 
     if (
       this.developerMode &&
@@ -394,6 +401,7 @@ export default class App {
       this.receiver = new HTTPReceiver({
         signingSecret: signingSecret || '',
         endpoints,
+        port,
         customRoutes,
         processBeforeResponse,
         signatureVerification,

src/receivers/HTTPReceiver.spec.ts

@@ -119,6 +119,38 @@ describe('HTTPReceiver', function () {
       assert.isNotNull(receiver);
     });
 
+    it('should accept a custom port', async function () {
+      // Arrange
+      const overrides = mergeOverrides(
+        withHttpCreateServer(this.fakeCreateServer),
+        withHttpsCreateServer(sinon.fake.throws('Should not be used.')),
+      );
+      const HTTPReceiver = await importHTTPReceiver(overrides);
+
+      const defaultPort = new HTTPReceiver({
+        signingSecret: 'secret',
+      });
+      assert.isNotNull(defaultPort);
+      assert.equal((defaultPort as any).port, 3000);
+
+      const customPort = new HTTPReceiver({
+        port: 9999,
+        signingSecret: 'secret',
+      });
+      assert.isNotNull(customPort);
+      assert.equal((customPort as any).port, 9999);
+
+      const customPort2 = new HTTPReceiver({
+        port: 7777,
+        signingSecret: 'secret',
+        installerOptions: {
+          port: 9999,
+        },
+      });
+      assert.isNotNull(customPort2);
+      assert.equal((customPort2 as any).port, 9999);
+    });
+
     it('should throw an error if redirect uri options supplied invalid or incomplete', async function () {
       const HTTPReceiver = await importHTTPReceiver();
       const clientId = 'my-clientId';

src/receivers/HTTPReceiver.ts

@@ -62,6 +62,7 @@ const missingServerErrorDescription = 'The receiver cannot be started because pr
 export interface HTTPReceiverOptions {
   signingSecret: string;
   endpoints?: string | string[];
+  port?: number; // if you pass another port number to #start() method, the argument will be used instead
   customRoutes?: CustomRoute[];
   logger?: Logger;
   logLevel?: LogLevel;
@@ -89,6 +90,9 @@ export interface HTTPReceiverInstallerOptions {
   metadata?: InstallURLOptions['metadata'];
   userScopes?: InstallURLOptions['userScopes'];
   callbackOptions?: CallbackOptions;
+  // This value exists here only for the compatibility with SocketModeReceiver.
+  // If you use only HTTPReceiver, the top-level is recommended.
+  port?: number;
 }
 
 /**
@@ -97,6 +101,8 @@ export interface HTTPReceiverInstallerOptions {
 export default class HTTPReceiver implements Receiver {
   private endpoints: string[];
 
+  private port: number; // you can override this value by the #start() method argument
+
   private routes: ReceiverRoutes;
 
   private signingSecret: string;
@@ -134,6 +140,7 @@ export default class HTTPReceiver implements Receiver {
   public constructor({
     signingSecret = '',
     endpoints = ['/slack/events'],
+    port = 3000,
     customRoutes = [],
     logger = undefined,
     logLevel = LogLevel.INFO,
@@ -159,6 +166,7 @@ export default class HTTPReceiver implements Receiver {
         return defaultLogger;
       })();
     this.endpoints = Array.isArray(endpoints) ? endpoints : [endpoints];
+    this.port = installerOptions?.port ? installerOptions.port : port;
     this.routes = prepareRoutes(customRoutes);
 
     // Verify redirect options if supplied, throws coded error if invalid
@@ -281,7 +289,15 @@ export default class HTTPReceiver implements Receiver {
         this.server = undefined;
       });
 
-      this.server.listen(portOrListenOptions, () => {
+      let listenOptions: ListenOptions | number = this.port;
+      if (portOrListenOptions !== undefined) {
+        if (typeof portOrListenOptions === 'number') {
+          listenOptions = portOrListenOptions as number;
+        } else if (typeof portOrListenOptions === 'object') {
+          listenOptions = portOrListenOptions as ListenOptions;
+        }
+      }
+      this.server.listen(listenOptions, () => {
         if (this.server === undefined) {
           return reject(new ReceiverInconsistentStateError(missingServerErrorDescription));
         }

src/receivers/SocketModeReceiver.spec.ts

@@ -93,7 +93,8 @@ describe('SocketModeReceiver', function () {
         },
       });
       assert.isNotNull(receiver);
-      assert.isOk(this.fakeServer.listen.calledWith(3000));
+      // since v3.8, the constructor does not start the server
+      // assert.isNotOk(this.fakeServer.listen.calledWith(3000));
     });
     it('should allow for customizing port the socket listens on', async function () {
       // Arrange
@@ -118,7 +119,8 @@ describe('SocketModeReceiver', function () {
         },
       });
       assert.isNotNull(receiver);
-      assert.isOk(this.fakeServer.listen.calledWith(customPort));
+      // since v3.8, the constructor does not start the server
+      // assert.isOk(this.fakeServer.listen.calledWith(customPort));
     });
     it('should allow for extracting additional values from Socket Mode messages', async function () {
       // Arrange

src/receivers/SocketModeReceiver.ts

@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import { SocketModeClient } from '@slack/socket-mode';
-import { createServer, IncomingMessage, ServerResponse } from 'http';
+import { createServer, IncomingMessage, ServerResponse, Server } from 'http';
 import { Logger, ConsoleLogger, LogLevel } from '@slack/logger';
 import { InstallProvider, CallbackOptions, InstallProviderOptions, InstallURLOptions } from '@slack/oauth';
 import { AppsConnectionsOpenResponse } from '@slack/web-api';
@@ -48,7 +48,7 @@ interface InstallerOptions {
   userScopes?: InstallURLOptions['userScopes'];
   clientOptions?: InstallProviderOptions['clientOptions'];
   authorizationUrl?: InstallProviderOptions['authorizationUrl'];
-  port?: number; // used to create a server when doing OAuth
+  port?: number; // used to create a server when doing OAuth or serving custom routes
 }
 
 /**
@@ -64,6 +64,10 @@ export default class SocketModeReceiver implements Receiver {
 
   public installer: InstallProvider | undefined = undefined;
 
+  private httpServer?: Server;
+
+  private httpServerPort?: number;
+
   private routes: ReceiverRoutes;
 
   public constructor({
@@ -127,9 +131,9 @@ export default class SocketModeReceiver implements Receiver {
       // use default or passed in installPath
       const installPath = installerOptions.installPath === undefined ? '/slack/install' : installerOptions.installPath;
       const directInstallEnabled = installerOptions.directInstall !== undefined && installerOptions.directInstall;
-      const port = installerOptions.port === undefined ? 3000 : installerOptions.port;
+      this.httpServerPort = installerOptions.port === undefined ? 3000 : installerOptions.port;
 
-      const server = createServer(async (req, res) => {
+      this.httpServer = createServer(async (req, res) => {
         // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
         const method = req.method!.toUpperCase();
 
@@ -196,14 +200,11 @@ export default class SocketModeReceiver implements Receiver {
         res.end();
       });
 
-      this.logger.debug(`Listening for HTTP requests on port ${port}`);
+      this.logger.debug(`Listening for HTTP requests on port ${this.httpServerPort}`);
 
       if (this.installer) {
-        this.logger.debug(`Go to http://localhost:${port}${installPath} to initiate OAuth flow`);
+        this.logger.debug(`Go to http://localhost:${this.httpServerPort}${installPath} to initiate OAuth flow`);
       }
-
-      // use port 3000 by default
-      server.listen(port);
     }
 
     this.client.on('slack_event', async (args) => {
@@ -224,11 +225,21 @@ export default class SocketModeReceiver implements Receiver {
   }
 
   public start(): Promise<AppsConnectionsOpenResponse> {
+    if (this.httpServer !== undefined) {
+      // This HTTP server is only for the OAuth flow support
+      this.httpServer.listen(this.httpServerPort);
+    }
     // start socket mode client
     return this.client.start();
   }
 
   public stop(): Promise<void> {
+    if (this.httpServer !== undefined) {
+      // This HTTP server is only for the OAuth flow support
+      this.httpServer.close((error) => {
+        this.logger.error(`Failed to shutdown the HTTP server for OAuth flow: ${error}`);
+      });
+    }
     return new Promise((resolve, reject) => {
       try {
         this.client.disconnect();