task-group

Node module to run a graph of tasks

This module manages a list of tasks and their dependencies. It will run tasks in parallel and will complete all of a tasks dependencies before running a task.

A task is very similar to a Makefile task, except that it will run a plain JS function. As in Makefile tasks, a task can have zero or more dependencies that must be completed before the task can be run. A TaskGroup will run as many tasks as possible in parallel, including dependencies, but will always ensure that all dependencies are complete before calling the task action.

Example

Also see the tests in the spec directory.

var TaskGroup = require('task-group');

var tasks = new TaskGroup();
tasks.task('dir', function(done) {
    fs.mkdir('my-dir', done);
});

tasks.task('file', ['dir'], function(done) {
    fs.writeFile('my-dir/file', 'Test file', done);
});

// Runs `dir` task first, and then `file` task
tasks.run('file', function(err) {
    // `err` contains the error if an error occurred in any of the tasks that
    // were run.
});

// Runs all tasks
tasks.run(function(err) {

});

// Run multiple tasks
tasks.run(['file', ...], function(err) {

});

Reference

TaskGroup()

This is the main class to use to manage the tasks. It contains an object containing the task names mapped to their dependencies and actions. The TaskGroup constructor is the only export from the module.

#task(name, [dependencies], [action])

This method registers a task with the specified name. The name must be a string. Dependencies can be specified as an array containing the names of tasks that must be run before this task. If dependencies is omitted, it is assumed that there are not dependencies. action is a function that will be called when the task is to be run. It will be provided a callback function that it must call when the task is complete, optionally passing an error to it.

#run([tasks], [callback])

Runs the specified tasks. tasks can be a single string or an array of strings specifying all the tasks to run. If tasks is null or omitted, it will run all the registered tasks. callback is a function that is called when all tasks are complete, with the first parameter being the error if an error occured, or null.