debug a nodejs process without inspect flags.

Note: works only on node>=8

Debugging currently requires providing the main node process flags like --inspect and/or --inspect-brk.

It works great, but sometimes we don't have full control over the process flags because we execute the process through a wrapper, generally jest, mocha or gulp and so many others.

Node 8 comes with the inspector module, which allows users to programmatically open an inspector.

Calling inspector in a blocking way is a bit cumbersome though, that's why this lib was created.

Install thebugger as a dev dependency:

npm i --save-dev thebugger
# or
yarn add --dev thebugger

Add thebugger() to the line of code you want to start debugging, which is where you'd add a debugger; statement.

require('thebugger')();

Wait until your nodejs process prints:

Debugger listening on ws://127.0.0.1:9222/038a3e89-b497-4558-9709-6a3da5ec3803
For help see https://nodejs.org/en/docs/inspector

Note: jest and other wrappers might not show this message but debugger still works on them.

Now you can open any Chrome DevTools and click on the green nodejs icon . After connecting with DevTools, you'll want to click on "step out" to start debugging your code.

Further instructions at: https://medium.com/@paul_irish/debugging-node-js-nightlies-with-chrome-devtools-7c4a1b95ae27

You also can use any DevTools frontend of your preference, like node inspect.