Merge pull request #32 from aoberoi/examples-error-handling

adds error handling to readme and examples, fixes #23

Author: aoberoi

README.md

@@ -72,10 +72,13 @@ const slackEvents = createSlackEventAdapter(process.env.SLACK_VERIFICATION_TOKEN
 const port = process.env.PORT || 3000;
 
 // Attach listeners to events by Slack Event "type". See: https://api.slack.com/events/message.im
-slackEvents.on('message', (event)=> {
+slackEvents.on('message', (event) => {
   console.log(`Received a message event: user ${event.user} in channel ${event.channel} says ${event.text}`);
 });
 
+// Handle errors (see `errorCodes` export)
+slackEvents.on('error', console.error);
+
 // Start a basic HTTP server
 slackEvents.start(port).then(() => {
   console.log(`server listening on port ${port}`);
@@ -115,6 +118,9 @@ slackEvents.on('message', (event)=> {
   console.log(`Received a message event: user ${event.user} in channel ${event.channel} says ${event.text}`);
 });
 
+// Handle errors (see `errorCodes` export)
+slackEvents.on('error', console.error);
+
 // Start the express application
 http.createServer(app).listen(port, () => {
   console.log(`server listening on port ${port}`);

examples/greet-and-react/index.js

@@ -98,6 +98,17 @@ slackEvents.on('reaction_added', (event, body) => {
     .catch(console.error);
 });
 
+// *** Handle errors ***
+slackEvents.on('error', (error) => {
+  if (error.code === slackEventsApi.errorCodes.TOKEN_VERIFICATION_FAILURE) {
+    // This error type also has a `body` propery containing the request body which failed verification.
+    console.error(`An unverified request was sent to the Slack events Request URL. Request body: \
+${JSON.stringify(error.body)}`);
+  } else {
+    console.error(`An error occurred while handling a Slack event: ${error.message}`);
+  }
+});
+
 // Start the express application
 const port = process.env.PORT || 3000;
 http.createServer(app).listen(port, () => {