Catching errors in test scripts with Mocha in Atom

atom-mocha.coffee

# courtesy of @jccguimaraes, https://gist.github.com/jccguimaraes/2e08be6f549448d9361c
path    = require 'path'
Mocha   = require 'mocha'

module.exports = (args) ->
    promise = new Promise (resolve, reject) ->

        # build a headless Atom
        window.atom = args.buildAtomEnvironment
            applicationDelegate: args.buildDefaultApplicationDelegate()
            window: window
            document: document
            configDirPath: process.env.ATOM_HOME
            enablePersistence: false
        testPath = path.join args.testPaths[0], 'test'

        # using Mocha programatically
        mocha = new Mocha().reporter('landing');
        Mocha.utils
            .lookupFiles(testPath, ['coffee'], true)
            .forEach mocha.addFile.bind(mocha)

        # run!
        runner = mocha.run (failure) ->
            resolve failure

    # catch and report errors occured in test scripts!
    promise.catch (error) ->
        # `error` is an instance of `Error`
        console.dir error

        # I don't know if there's other way to tell whether the spec was
        # invoked from the editor, or ran in console, but ::isMaximized() seems do just fine
        if window.atom.isMaximized()
            # spec probably invoked in editor
            window.atom.close() # close the spec runner if you like
        else
            # spec probably runs in console
            process.exit 1 # do something to quit the process, or it HANGS!

    return promise