Re-fix slackapi#395 by adjusting the processBeforeResponse option

seratch · Apr 1, 2020 · c2bb022 · c2bb022
1 parent 0d662d0
commit c2bb022
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Showing 2 changed files with 29 additions and 7 deletions.
diff --git a/src/App.ts b/src/App.ts
@@ -154,6 +154,9 @@ export default class App {
   /** Receiver - ingests events from the Slack platform */
   private receiver: Receiver;
 
+  /** Always call ack() after event listener completion if true */
+  private processBeforeResponse: boolean = false;
+
   /** Logger */
   private logger: Logger;
 
@@ -256,6 +259,7 @@ export default class App {
         });
       }
     }
+    this.processBeforeResponse = processBeforeResponse;
 
     // Conditionally use a global middleware that ignores events (including messages) that are sent from this app
     if (ignoreSelf) {
@@ -580,8 +584,11 @@ export default class App {
     if (type !== IncomingEventType.Event) {
       listenerArgs.ack = ack;
     } else {
-      // Events API requests are acknowledged right away, since there's no data expected
-      await ack();
+      // If processBeforeResponse is true, ack() call should be after the listener completion
+      if (!this.processBeforeResponse) {
+        // Events API requests are acknowledged right away, since there's no data expected
+        await ack();
+      }
     }
 
     // Get the client arg
@@ -635,6 +642,9 @@ export default class App {
           } else if (rejectedListenerResults.length > 1) {
             throw new MultipleListenerError(rejectedListenerResults.map(rlr => rlr.reason));
           }
+          if (this.processBeforeResponse && type === IncomingEventType.Event) {
+            await ack();
+          }
         },
       );
     } catch (error) {

diff --git a/src/ExpressReceiver.ts b/src/ExpressReceiver.ts
@@ -96,12 +96,24 @@ export default class ExpressReceiver implements Receiver {
 
     try {
       await this.bolt?.processEvent(event);
-      if (storedResponse !== undefined) {
-        if (typeof storedResponse === 'string') {
-          res.send(storedResponse);
-        } else {
-          res.json(storedResponse);
+
+      if (this.processBeforeResponse) {
+        let spentMillis = 0;
+        const millisForTimeout = 10;
+        // Wait here until the isAcknowledged is marked as true or 3 seconds have passed
+        while (!isAcknowledged && spentMillis < 3000) {
+          await new Promise(resolve => setTimeout(resolve, millisForTimeout));
+          spentMillis += millisForTimeout;
         }
+        if (isAcknowledged) {
+          this.logger.debug(`The listener execution completed in ${spentMillis} millis`);
+          if (typeof storedResponse === 'string') {
+            res.send(storedResponse);
+          }  else {
+            res.json(storedResponse);
+          }
+          this.logger.debug('Acknowledged after the listener completion');
+        } // Otherwise, this Bolt app never responds to this request and above setTimeout outputs an error message
       }
     } catch (err) {
       res.send(500);