How to debug a Gulp task?

Question

How do I debug a gulp task defined in my gulpfile.js with a debugger such as the Google Chrome debugger, stepping through the task\'s code line by line?

Answer 1

If you are using webstorm you can right click the task in the gulp panel and select debug.

Answer 2

For anyone using VS Code 1.10+

1. Open the debug panel.
2. Click on the settings icon.
3. Click on Add Configuration button.
4. Choose Node.js: Gulp Task.

This is how your launch.json file should look.

{
  // 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": "launch",
      "name": "Gulp task",
      "program": "${workspaceFolder}/node_modules/gulp/bin/gulp.js",
      "args": [
        "yourGulpTaskName"
      ]
    }
  ]
}

Answer 3

Thanks user2943490, on Windows I found this version worked for me:

node --inspect --debug-brk ./node_modules/gulp/bin/gulp.js --verbose

Answer 4

Version (node v8.11.3, npm 6.2.0, gulp 3.9.1)

Windows 10 & git bash

Install Node.js V8 --inspector Manager (NiM) & set to your preference

Try this:

node --inspect-brk ./node_modules/gulp/bin/gulp.js --verbose

Answer 5

With Node.js version 6.3+ you can use the --inspect flag when running your task.

To debug a gulp task named css:

1. Find out where your gulp executable lives. If gulp is installed locally, this will be at node_modules/.bin/gulp. If gulp is installed globally, run which gulp (Linux/Mac) or where gulp (Windows) in a terminal to find it.

2. Run one of these commands according to your version of Node.js. If required, replace ./node_modules/.bin/gulp with the path to your gulp installation from step 1.

   • Node.js 6.3+: node --inspect --debug-brk ./node_modules/.bin/gulp css
   • Node.js 7+: node --inspect-brk ./node_modules/.bin/gulp css

3. Use Chrome to browse to chrome://inspect.

The --debug-brk (Node.js 6.3+) and --inspect-brk (Node.js 7+) flags are used to pause code execution on the first line of code of your task. This gives you a chance to open up the Chrome debugger and set breakpoints before the task finishes.

If you don't want the debugger to pause on first line of code, just use the --inspect flag.

You can also install the Node.js Inspector Manager (NIM) extension for Chrome to help with step 3. This will automatically open up a Chrome tab with the debugger ready to go, as an alternative to manually browsing to a URL.

Answer 6

I liked the answer of @Avi Y. but I suppose people would had appreciated a more complete script :

gulp.task('nodemon', ['sass'], function(cb) {
var started = false;
    consoleLog('nodemon started');
return nodemon({
    //HERE REMOVE THE COMMENT AT THE BEGINING OF THE LINE YOU NEED
    //exec: 'node --inspect --debug-brk node_modules/gulp/bin/gulp.js', 
    exec: 'node --inspect --debug-brk',
    //exec: 'node --inspect',
    script: path.server,
    ignore: ['*/gulpfile.js', 'node_modules/*'],
    verbose: true
}).on('start', function() {
    if (!started) {
        cb();
        started = true;
    }
}).on('restart', function() {
    consoleLog('nodemon restarted the server');
});});