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.