Asynchronous tasks in grunt.registerTask

Question

I need to call two functions within grunt.registerTask, but the second function has to be called after the first function is done.

So I was wondering if we can use callbacks or promises or other asynchronous mechanisms within grunt.registerTask.

(More specifically, I need to launch karma in my first function call, and run karma in the second function call (to execute the initial unit tests). But in order to run karma, I need to launch it first. And that's what I'm missing.)

Answer 1

I had this:

grunt.registerTask("name_of_task", ["task_a", "task_b", "task_c"]);

And "task_b" had to be executed after "task_a" was done. The problem is that "task_a" is asynchronous and returns right away, so I needed a way to give "task_a" a few seconds to execute.

The solution:

grunt.registerTask("name_of_task", ["task_a", "task_b:proxy", "task_c"]);

grunt.registerTask("task_b:proxy", "task_b description", function () {
        var done = this.async();

        setTimeout(function () {
            grunt.task.run("task_b");
            done();
        }, 2000);
    });
};