Chrome Devtools Dedicated Node.js Inspector not stopping at breakpoints

This is a problem that has been extremely annoying to me since 10.13 went to LTS and I upgraded from 8 to 10.

I was unable to find anything about this issue until I saw this question here on stack overflow, that was the catalyst I needed to be able find more about the problem and discover the cause and the solution.

You can find out more here: https://github.com/nodejs/node/issues/23693

The Why: Basically it is because of a change to the debugger protocol in Node.

The Solution: Upgrade Chrome to 71 or later which supports the change in the protocol.

Much Better Solution: Install NIM: https://chrome.google.com/webstore/detail/nodejs-v8-inspector-manag/gnhhdgbaldcilmgcpfddgdbkhjohddkj then go to the NIM settings and change the selected DevTools version to the one from chrome-devtools-frontend.appspot.com ( see more about this option here: https://june07.com/blog/nim-custom-devtools-url/ )

Use the --inspect-brk flag instead

I ended up opening up an issue on the devtools protocol github page.

I got an immediate answer. Basically, because I was using the --inspect flag to start the Node.js debugger, my JavaScript was being executed before the debugger process was connecting to the DevTools server. Therefore breakpoint information would be relayed too late and no breakpoints would be triggered.

Example: node --inspect-brk myscript.js

They're currently trying to improve this use case. Here's the actual reply:

We are working on better workflow here but for now --inspect-brk is only one way. With --inspect-brk node waits DevTools frontend connection. On connection DevTools send all breakpoints information and starts JavaScript execution in node. With --inspect node starts JavaScript execution without waiting for DevTools frontend. As soon as DevTools connected, we send the same breakpoint information to node but it can be too late since some JavaScript is already executed.

The Node.js docs are not very clear on this subtlety as of 4/6/2018. I will submit a PR on their repo to update the docs. BTW, if you are not aware, even without the V8 integration, the built-in debugger is very powerful. Explore all the possibilities of the debugging utility in the docs.

I have this issue too: Chrome Devtools Inspector not stopping at breakpoints.

My problematic software versions:

• Chrome: Version 70.0.3538.77 (Official Build) (64-bit)
• Node: v10.12.0

A workaround I found is to downgrade NodeJS to version 8.12.0 (the latest 8.x version). Node version 8.x works for me.

$ node -v
v8.12.0

I also tried Node version 10.13.0, 11.1.0, none of them works for me.

FYI: How to change Node version