Fix slackapi#405 by providing a better way to configure logger

src/App.spec.ts

@@ -694,6 +694,56 @@ describe('App', () => {
           assert.isTrue(fakeLogger.info.called);
           assert.isTrue(fakeLogger.debug.called);
         });
+
+        it('should work in the case both logger and logLevel are given', async () => {
+          // Arrange
+          const App = await importApp(overrides); // tslint:disable-line:variable-name
+          const fakeLogger = createFakeLogger();
+          const app = new App({
+            logger: fakeLogger,
+            logLevel: LogLevel.DEBUG,
+            receiver: fakeReceiver,
+            authorize: sinon.fake.resolves(dummyAuthorizationResult),
+          });
+          app.use(({ logger, body, next }) => {
+            logger.info(body);
+            next();
+          });
+
+          app.event('app_home_opened', ({ logger, event }) => {
+            logger.debug(event);
+          });
+
+          const receiverEvents = [
+            {
+              body: {
+                type: 'event_callback',
+                token: 'XXYYZZ',
+                team_id: 'TXXXXXXXX',
+                api_app_id: 'AXXXXXXXXX',
+                event: {
+                  type: 'app_home_opened',
+                  event_ts: '1234567890.123456',
+                  user: 'UXXXXXXX1',
+                  text: 'hello friends!',
+                  tab: 'home',
+                  view: {},
+                },
+              },
+              respond: noop,
+              ack: noop,
+            },
+          ];
+
+          // Act
+          receiverEvents.forEach(event => fakeReceiver.emit('message', event));
+          await delay();
+
+          // Assert
+          assert.isTrue(fakeLogger.info.called);
+          assert.isTrue(fakeLogger.debug.called);
+          assert.isTrue(fakeLogger.setLevel.called);
+        });
       });
 
       describe('client', () => {

src/App.ts

@@ -165,20 +165,28 @@ export default class App {
     botId = undefined,
     botUserId = undefined,
     authorize = undefined,
-    logger = new ConsoleLogger(),
-    logLevel = LogLevel.INFO,
+    logger = undefined,
+    logLevel = undefined,
     ignoreSelf = true,
     clientOptions = undefined,
   }: AppOptions = {}) {
 
-    this.logger = logger;
-    this.logger.setLevel(logLevel);
+    if (typeof logger === 'undefined') {
+      // Initialize with the default logger
+      const consoleLogger = new ConsoleLogger();
+      consoleLogger.setName('bolt-app');
+      this.logger = consoleLogger;
+    } else {
+      this.logger = logger;
+    }
+    if (typeof logLevel !== 'undefined' && this.logger.getLevel() !== logLevel) {
+      this.logger.setLevel(logLevel);
+    }
     this.errorHandler = defaultErrorHandler(this.logger);
-
     this.clientOptions = {
       agent,
-      logLevel,
-      logger,
+      // App propagates only the log level to WebClient as WebClient has its own logger
+      logLevel: this.logger.getLevel(),
       tls: clientTls,
       slackApiUrl: clientOptions !== undefined ? clientOptions.slackApiUrl : undefined,
     };
@@ -226,7 +234,13 @@ export default class App {
         );
       } else {
         // Create default ExpressReceiver
-        this.receiver = new ExpressReceiver({ signingSecret, logger, endpoints, agent, clientTls });
+        this.receiver = new ExpressReceiver({
+          signingSecret,
+          endpoints,
+          agent,
+          clientTls,
+          logger: this.logger,
+        });
       }
     }