Multiple pumps inside a single task

[janrembold]

Is there any best-practice-way of using multiple pumps inside a single task and return the callback after all of them finished?

Maybe a simplified demo code clearifies the question:

gulp.task('compress', function (cb) {
  const folders = ['folder1', 'folder2'];

  folders.forEach((folder) => {
    pump([
        gulp.src(`lib/${folder}/*.js`),
        uglify(),
        gulp.dest(`${folder}/dist/`)
      ],
      cb // <= this is wrong of course
    );
  });  

  // cb(); // calling it here might be as wrong as well
});

This is, of course, not a real life code snippet. But it shows the need to run multiple pumps inside a single task. In my real case the source and destination folders are a little bit more complex.

Is there any way to solve that with pump?

[janrembold]

We solved this by adding Promises around each pump and call the callback function after all promises got resolved. See https://github.com/biotope/biotope-build/blob/master/tasks/uglify.js#L25

[zhuchuji]

@janrembold Hi, how to make the code work in the above example? I face the same problem and it throws the error: task completion callback called too many times. My codes:

gulp.task('script', function(cb) {
	pump([
		gulp.src('file.js'),
		sourcemaps.init(),
		uglifyJs({}),
		concat('scripts.common.min.js'),
		sourcemaps.write('.'),
		gulp.dest(scriptBuiltPath)
	], cb);
	pump([
		gulp.src('another-file.js'),
		sourcemaps.init(),
		uglifyJs({}),
		rename({ extname: '.min.js' }),
		sourcemaps.write('.'),
		gulp.dest(scriptBuiltPath)
	], cb);
})

[janrembold]

@zhuchuji Please see the link above for a working example using Promises. You should only call cb() once

[zhuchuji]

@janrembold Got it. Thank you.