[v2] Convert receivers to use App#processEvent

src/App.ts

@@ -1,3 +1,5 @@
+import { Agent } from 'http';
+import { SecureContextOptions } from 'tls';
 import util from 'util';
 import {
   WebClient,
@@ -39,21 +41,24 @@ import {
   BlockAction,
   InteractiveMessage,
   SlackViewAction,
-  Receiver,
-  ReceiverEvent,
   RespondArguments,
 } from './types';
 import { IncomingEventType, getTypeAndConversation, assertNever } from './helpers';
-import { ErrorCode, CodedError, errorWithCode, asCodedError } from './errors';
+import { Receiver, ReceiverEvent } from './receiver';
+import {
+  CodedError,
+  asCodedError,
+  AppInitializationError,
+} from './errors';
 import { MiddlewareContext } from './types/middleware';
 const packageJson = require('../package.json'); // tslint:disable-line:no-require-imports no-var-requires
 
 /** App initialization options */
 export interface AppOptions {
   signingSecret?: ExpressReceiverOptions['signingSecret'];
   endpoints?: ExpressReceiverOptions['endpoints'];
-  agent?: ExpressReceiverOptions['agent']; // also WebClientOptions['agent']
-  clientTls?: ExpressReceiverOptions['clientTls']; // also WebClientOptions['tls']
+  agent?: Agent;
+  clientTls?: Pick<SecureContextOptions, 'pfx' | 'key' | 'passphrase' | 'cert' | 'ca'>;
   convoStore?: ConversationStore | false;
   token?: AuthorizeResult['botToken']; // either token or authorize
   botId?: AuthorizeResult['botId']; // only used when authorize is not defined, shortcut for fetching
@@ -72,7 +77,7 @@ export { LogLevel, Logger } from '@slack/logger';
 export interface Authorize {
   (
     source: AuthorizeSourceData,
-    body: ReceiverEvent['body'],
+    body: AnyMiddlewareArgs['body'],
   ): Promise<AuthorizeResult>;
 }
 
@@ -107,7 +112,7 @@ export interface ViewConstraints {
 }
 
 export interface ErrorHandler {
-  (error: CodedError): void;
+  (error: CodedError): Promise<void>;
 }
 
 class WebClientPool {
@@ -195,16 +200,14 @@ export default class App {
 
     if (token !== undefined) {
       if (authorize !== undefined) {
-        throw errorWithCode(
+        throw new AppInitializationError(
           `Both token and authorize options provided. ${tokenUsage}`,
-          ErrorCode.AppInitializationError,
         );
       }
       this.authorize = singleTeamAuthorization(this.client, { botId, botUserId, botToken: token });
     } else if (authorize === undefined) {
-      throw errorWithCode(
+      throw new AppInitializationError(
         `No token and no authorize options provided. ${tokenUsage}`,
-        ErrorCode.AppInitializationError,
       );
     } else {
       this.authorize = authorize;
@@ -219,20 +222,15 @@ export default class App {
     } else {
       // No custom receiver
       if (signingSecret === undefined) {
-        throw errorWithCode(
-          'Signing secret not found, so could not initialize the default receiver. Set a signing secret or use a ' +
-          'custom receiver.',
-          ErrorCode.AppInitializationError,
+        throw new AppInitializationError(
+            'Signing secret not found, so could not initialize the default receiver. Set a signing secret or use a ' +
+            'custom receiver.',
         );
-      } else {
-        // Create default ExpressReceiver
-        this.receiver = new ExpressReceiver({ signingSecret, logger, endpoints, agent, clientTls });
       }
+      // Create default ExpressReceiver
+      this.receiver = new ExpressReceiver({ signingSecret, logger,  endpoints });
     }
-
-    // Subscribe to messages and errors from the receiver
-    this.receiver.on('message', message => this.onIncomingEvent(message));
-    this.receiver.on('error', error => this.onGlobalError(error));
+    this.receiver.init(this);
 
     // Conditionally use a global middleware that ignores events (including messages) that are sent from this app
     if (ignoreSelf) {
@@ -408,7 +406,7 @@ export default class App {
   /**
    * Handles events from the receiver
    */
-  private async onIncomingEvent(event: ReceiverEvent): Promise<void> {
+  public async processEvent(event: ReceiverEvent): Promise<void> {
     const { body, ack } = event;
     // TODO: when generating errors (such as in the say utility) it may become useful to capture the current context,
     // or even all of the args, as properties of the error. This would give error handling code some ability to deal
@@ -426,13 +424,15 @@ export default class App {
 
     // Initialize context (shallow copy to enforce object identity separation)
     const source = buildSource(type, conversationId, bodyArg);
-    const authorizeResult = await (this.authorize(source, bodyArg).catch((error) => {
-      this.onGlobalError(authorizationErrorFromOriginal(error));
-    }));
-    if (authorizeResult === undefined) {
+    let authorizeResult;
+
+    try {
+      authorizeResult = await this.authorize(source, bodyArg);
+    } catch (error) {
       this.logger.warn('Authorization of incoming event did not succeed. No listeners will be called.');
       return;
     }
+
     const context: Context = { ...authorizeResult };
 
     // Factory for say() utility
@@ -553,15 +553,16 @@ export default class App {
         ...(listenerArgs as MiddlewareContext<AnyMiddlewareArgs>),
       });
     } catch (error) {
-      this.onGlobalError(error);
+      await event.ack(asCodedError(error));
+      return this.handleError(error);
     }
   }
 
   /**
    * Global error handler. The final destination for all errors (hopefully).
    */
-  private onGlobalError(error: Error): void {
-    this.errorHandler(asCodedError(error));
+  public handleError(error: Error): Promise<void> {
+    return this.errorHandler(asCodedError(error));
   }
 
 }
@@ -618,6 +619,8 @@ function isBlockActionOrInteractiveMessageBody(
 function defaultErrorHandler(logger: Logger): ErrorHandler {
   return (error) => {
     logger.error(error);
+
+    throw error;
   };
 }
 
@@ -648,15 +651,3 @@ function selectToken(context: Context): string | undefined {
 
 /* Instrumentation */
 addAppMetadata({ name: packageJson.name, version: packageJson.version });
-
-/* Error handling helpers */
-function authorizationErrorFromOriginal(original: Error): AuthorizationError {
-  const error = errorWithCode('Authorization of incoming event did not succeed.', ErrorCode.AuthorizationError);
-  (error as AuthorizationError).original = original;
-  return error as AuthorizationError;
-}
-
-export interface AuthorizationError extends CodedError {
-  code: ErrorCode.AuthorizationError;
-  original: Error;
-}

src/ExpressReceiver.spec.ts

@@ -1,21 +1,18 @@
 // tslint:disable:no-implicit-dependencies
 import 'mocha';
-
 import { Logger, LogLevel } from '@slack/logger';
 import { assert } from 'chai';
 import { Request, Response } from 'express';
-import { Agent } from 'http';
 import sinon, { SinonFakeTimers } from 'sinon';
 import { Readable } from 'stream';
 
 import ExpressReceiver, {
   respondToSslCheck,
   respondToUrlVerification,
-  verifySignatureAndParseBody,
+  verifySignatureAndParseRawBody,
 } from './ExpressReceiver';
 
 describe('ExpressReceiver', () => {
-
   const noopLogger: Logger = {
     debug(..._msg: any[]): void { /* noop */ },
     info(..._msg: any[]): void { /* noop */ },
@@ -43,10 +40,6 @@ describe('ExpressReceiver', () => {
         signingSecret: 'my-secret',
         logger: noopLogger,
         endpoints: { events: '/custom-endpoint' },
-        agent: new Agent({
-          maxSockets: 999,
-        }),
-        clientTls: undefined,
       });
       assert.isNotNull(receiver);
     });
@@ -58,6 +51,7 @@ describe('ExpressReceiver', () => {
         signingSecret: 'my-secret',
         logger: noopLogger,
       });
+
       await receiver.start(9999);
       await receiver.stop();
     });
@@ -102,7 +96,7 @@ describe('ExpressReceiver', () => {
       });
     });
 
-    describe('url_verification requset handler', () => {
+    describe('url_verification request handler', () => {
       it('should handle valid requests', async () => {
         // Arrange
         // tslint:disable-next-line: no-object-literal-type-assertion
@@ -141,7 +135,7 @@ describe('ExpressReceiver', () => {
     });
   });
 
-  describe('verifySignatureAndParseBody', () => {
+  describe('verifySignatureAndParseRawBody', () => {
 
     let clock: SinonFakeTimers;
 
@@ -196,7 +190,7 @@ describe('ExpressReceiver', () => {
       const next = (error: any) => { state.error = error; };
 
       // Act
-      const verifier = verifySignatureAndParseBody(noopLogger, signingSecret);
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       await verifier(req, resp, next);
     }
 
@@ -245,24 +239,15 @@ describe('ExpressReceiver', () => {
       const result: any = {};
       const resp = buildResponseToVerify(result);
 
-      let error: string = '';
-      let warn: string = '';
-      const logger = {
-        error: (msg: string) => { error = msg; },
-        warn: (msg: string) => { warn = msg; },
-      } as any as Logger;
-
       const next = sinon.fake();
 
       // Act
-      const verifier = verifySignatureAndParseBody(logger, signingSecret);
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       await verifier(req, resp, next);
 
       // Assert
       assert.equal(result.code, 400);
       assert.equal(result.sent, true);
-      assert.equal(error, 'Failed to parse body as JSON data for content-type: undefined');
-      assert.equal(warn, 'Parsing request body failed (error: SyntaxError: Unexpected token o in JSON at position 1)');
     }
 
     it('should fail to parse request body without content-type header', async () => {
@@ -301,7 +286,7 @@ describe('ExpressReceiver', () => {
       const next = sinon.fake();
 
       // Act
-      const verifier = verifySignatureAndParseBody(noopLogger, signingSecret);
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       await verifier(req, resp, next);
 
       // Assert
@@ -355,7 +340,8 @@ describe('ExpressReceiver', () => {
       const next = sinon.fake();
 
       // Act
-      const verifier = verifySignatureAndParseBody(noopLogger, signingSecret);
+
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       await verifier(req, resp, next);
 
       // Assert
@@ -388,7 +374,7 @@ describe('ExpressReceiver', () => {
       const next = sinon.fake();
 
       // Act
-      const verifier = verifySignatureAndParseBody(noopLogger, signingSecret);
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       await verifier(req, resp, next);
 
       // Assert
@@ -414,7 +400,7 @@ describe('ExpressReceiver', () => {
       const next = sinon.fake();
 
       // Act
-      const verifier = verifySignatureAndParseBody(noopLogger, signingSecret);
+      const verifier = verifySignatureAndParseRawBody(noopLogger, signingSecret);
       verifier(req, resp, next);
       await verifier(req, resp, next);