Learning TypeScript 2.x - Second Edition

Returning a stream

All we need to do is to use a stream as the return of the task definition function. This is simple because the pipe operator returns a stream:

gulp.task("sync", function () { 
    return gulp.src([ 
        "src/**/**.ts" 
    ]) 
    .pipe(somePlugin({})) 
    .pipe(somePlugin ()); 
}); 

Now that we have some synchronous tasks, we can use them as a subtask of a new task named async:

gulp.task("async", ["sync1", "sync2"], function () {   
    // This task will not start until 
    // the sync tasks are completed! 
    console.log("Done!"); 
}); 

As we can see in the preceding code snippet, it is also possible to define a task that has some subtasks. However, if the complexity of our build process increases, we can end up with a very difficult to follow task dependency ...