doc: fix/improve inspector profiler example

The first parameter to the callback is `err`. Fix that. Expand example to demonstrate an actual write to disk. PR-URL: #19379 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Franziska Hinkelmann <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Luigi Pinca <[email protected]>
nodejs · Mar 22, 2018 · cc7ba0b · cc7ba0b
1 parent 29a04b7
commit cc7ba0b
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/doc/api/inspector.md b/doc/api/inspector.md
@@ -145,7 +145,7 @@ protocol. Here's a simple example showing how to use the [CPU profiler][]:
 
 ```js
 const inspector = require('inspector');
-
+const fs = require('fs');
 const session = new inspector.Session();
 session.connect();
 
@@ -154,8 +154,11 @@ session.post('Profiler.enable', () => {
     // invoke business logic under measurement here...
 
     // some time later...
-    session.post('Profiler.stop', ({ profile }) => {
+    session.post('Profiler.stop', (err, { profile }) => {
       // write profile to disk, upload, etc.
+      if (!err) {
+        fs.writeFileSync('./profile.cpuprofile', JSON.stringify(profile));
+      }
     });
   });
 });