Task inheritance in gulp, parent gulpfile.js - node.js

Question

I am using node/gulp to run/build my projects. Accross those projects my gulpfiles look very similar. Since I'm coming from a Java/Maven background I was looking for sth. like a parent gulpfile one could inherit basic tasks from (this is easily possible with a parent pom.xml in maven).
Is this somehow build into gulp, are there modules doing this or do I need to figure this myself?
I could think of having a node module doing nothing else then providing basic gulp tasks that one can require from his dependent gulp file. Any experiences on an approach like this?
BR
Chris

Answer 1

You could just export the gulp object in your parent gulpfile and then require it in the child gulpfiles:
project/gulpfile.js:
var gulp = require('gulp');
gulp.task('commontask', function () { });
module.exports = gulp;
project/subproject/gulpfile.js:
var gulp = require('../gulpfile.js');
gulp.task('subtask', [ 'commontask' ], function() { });
Running subtask from the project/subproject directory:
> gulp subtask
[12:38:05] Using gulpfile ~/project/subproject/gulpfile.js
[12:38:05] Starting 'commontask'...
[12:38:05] Finished 'commontask' after 50 μs
[12:38:05] Starting 'subtask'...
[12:38:05] Finished 'subtask' after 20 μs
EDIT: The above won't work if the parent gulpfile isn't part of the same package (e.g. my-app) but rather from another package that you depend on (e.g. my-common-tasks). The reason is that the way module loading in Node.js works, you end up with two instances of gulp: one in my-common-tasks and one in my-app. Your tasks will be defined in the instance from my-common-tasks, but the gulp CLI will look for the tasks in the instance from my-app.
Instead you have to pass the gulp instance from my-app to my-common-tasks:
my-common-tasks/gulpfile.js:
module.exports = function(gulp) {
gulp.task('common-task', function () { });
};
my-app/gulpfile.js:
var gulp = require('gulp');
require('my-common-tasks')(gulp);
gulp.task('sub-task', [ 'common-task' ], function() { });