To debug, we have to modify the grunt file under bin. On my machine, grunt is installed globally, so I went to /usr/local/lib/node_modules/grunt/bin
I opened the file and modified:
#!/usr/bin/env node
To
#!/usr/bin/env node --debug-brk
--debug-brk will break on the first line of javascript ran.
Doing that alone isn't quite enough though, since you won't be able to find you're grunt task js file in the drop down in node inspector, so you have to modify the file you're interested in debugging by adding debugger; where you want the breakpoint to happen.
Now you can click continue after the first break, and you'll break on you're debugger; line
Pretty kludgy, but it's the only way I've found so far.
To run grunt in debug, you need to pass the grunt script to node explicitly:
node-debug $(which grunt) task
and put a debugger; line in your task. node-inspector will then open a browser with debugging tools.
Edit 28 Feb 2014
node-inspector has added the command node-debug, which launches node in a --debug state and opens the browser to the node-inspector page, stopping when it hits the first debugger line or set breakpoint.
Edit 30 January 2015
On Windows, things are a touch more complicated. See the answer from @e.gluhotorenko for instructions.
To start debugging, open the following URL in Chrome:
chrome-devtools://devtools/bundled/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:9229/232652c3-f63c-4b00-8de9-17dfad5db471
Open that URL in chrome, and you're good to go!
I'm using Node 7.3.0 and I'm on Mac. You might have to follow some of the advice in other posts to get it going on Windows.
If you want to launch the grunt task in debug mode and break at first line:
node --inspect-brk $(which grunt) taskName
If you want to launch the grunt task in debug mode at a specific port:
node --inspect-brk=8080 $(which grunt) taskName
if you want to attache VSCODE to the node process running the debugging session of grunt, use the following configuration in vscode:
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"type": "node",
"request": "attach",
"name": "Attach by port IP 5656",
"port": 8080
}
]
}