debuggingnode.jsv8node-inspector

How to debug node js app with breakpoints and everything?

I've installed node-inspector just to find out that it doesn't support breakpoints :| What's the point in it at all, bearing in mind that on big part node code is asynchronous and you simply cannot follow it step by step?..

I'm definitely missing a point here...

Anyway to debug node code with breakpoints and everything?

Solution

  • (For Node 8 and later)

    Node.js has a built-in debugger. Normally you can turn on the debugger in two ways:

    1. Start your Node.js app or script with the --inspect or --inspect-brk switch. For example:

      $ node.js --inspect index.js

    (Note: --inspect-brk breaks before user code starts)

    1. If for some reason you cannot start your Node.js app or script with the --inspect switch, you can still instruct the Node.js process to start listening for debugging messages by signalling it with SIGUSR1 (on Linux and OS X). For Node 8 and later it will activate the Inspector API, same as the --inspect switch

      $ kill -sigusr1 23485

    (Note: you need to replace 23485 with your own Node.js process ID)

    With the debugger turned on, you can open the Google Chrome browser, and type in the address bar chrome://inspect

    Then you should see an entry listed under "Remote Target". Go ahead and click "inspect".

    Now you can set breakpoints and start debugging your code.

    Reference:

    1. https://nodejs.org/en/docs/guides/debugging-getting-started/
    2. Related issue on stackoverflow: Chrome Devtools Dedicated Node.js Inspector not stopping at breakpoints