oblige

Tiny task-based module for whipping up "hookable" build scripts, with the intention of being used in decorated interfaces.

Installation

npm install oblige

API

tasks = require('oblige')

The "root" oblige instance. Captures the events across all oblige instances.

tasks.create(name, [meta], taskfn)

Creates a new task. meta is optional, and handles two properties (also optional):

• meta.description: defaults to an empty string.
• meta.before: A string or array of string task names - task.run will call these tasks in sequence before running the task.

taskfn is called when running the task, and is passed a done callback to the first argument you should call when it's complete. If done is passed an error, any parent tasks will stop running.

tasks.run(name, callback)

Runs a task, calling callback(err) when complete.

tasks.on('data', callback)

Every time a new task is created, oblige emits it as a data event with the task that's been loaded.

child = tasks()

Similarly to timber, you can create child task handlers - these are almost totally independent, except the "root" instance will capture events from these as well.

child = tasks('namespaced')

By supplying a string key to the function, you're returned a new instance unique to that name - use it twice in different places and you'll receive the same instance.

Example

Take a simple task runner:

// runner.js
var oblige = require('oblige')
 
var command = process.argv[2]
  , taskName = process.argv[3]
 
if (command === 'list') {
  oblige.on('data', function(task) {
    console.log(task.name + ': ' + task.description)
  })
}
 
require('./tasks')
 
if (command === 'run') {
  oblige.run(taskName, function(err) {
    if (err) throw err
    console.log('ok!')
    process.exit()
  })
}

And a tasks file:

// tasks.js
var oblige = require('oblige')
 
oblige.task('minify', {
  description: 'Minifies frontend assets'
  before: [
      'minify-css'
    , 'minify-js'
  ]
})
 
oblige.task('minify-css', {
  description: 'Minifies CSS'
}, function(done) {
  console.log('minifying css...')
  // ...
  done()
})
 
oblige.task('minify-js', {
  description: 'Minifies JavaScript'
}, function(done) {
  console.log('minifying js...')
  // ...
  done()
})

You would be able to run the command and get this:

$ node runner.js list
minify: Minifies frontend assets
minify-css: Minifies CSS
minify-js: Minifies JavaScript
 
$ node runner.js run minify
minifying css...
minifying js...
ok!
 
$ node runner.js run minify-js
minifying js...
ok!