Grunt File for Arrow Publishing (credit goes to Fokke for that one)

Gruntfile.js

var child_process = require('child_process'),
    async = require('async');

var REGEXP_VERSIONS = /versions: ((?:(?:, )?[0-9]+\.[0-9]+\.[0-9]+)+)\..+currently: ([0-9]+\.[0-9]+\.[0-9]+)/;

module.exports = function(grunt) {

    grunt.initConfig({
        spawn: {
            bump: {
                command: 'npm',
                args: ['version', 'patch', '-m', 'bump version']
            },
            publish: {
                command: 'appc',
                args: ['acs', 'publish']
            }
        },
        nodemailer: {
            options: {
                transport: {
                    type: 'SMTP',
                    options: {
                    	host: '<HOST>',
                        auth: {
                            user: '<USER>',
                            pass: '<PASS>'
                        },
                        secure: true
                    }
                },
                message: {
                    from: 'Fokke Zandbergen <fzandbergen@appcelerator.com>',
                    subject: '[DEPLOY] https://community.appcelerator.com',
                    text: 'Publishing a new version to https://community.appcelerator.com',
                },
                recipients: [{
                    email: 'deploy@appcelerator.com',
                    name: 'Deploy'
                }]
            },
            deploy: {}
        }
    });

    grunt.loadNpmTasks('grunt-nodemailer');

    grunt.registerMultiTask('spawn', 'Spawns a child process', function() {

        if (!this.data) {
            return grunt.fail.fatal('Configuration is missing');
        }

        if (!this.data.command) {
            return grunt.fail.fatal('Command is missing');
        }

        var done = this.async();

        var spawn = child_process.spawn,
            child = spawn(this.data.command, this.data.args || []);

        child.stdout.on('data', function(data) {
            grunt.log.write(data);
        });

        child.stderr.on('data', function(data) {
            grunt.log.error(data);
        });

        child.on('close', function(code) {
            done(code === 0);
        });
    });

    grunt.registerTask('unpublish', 'Unpublished old versions', function() {
        var done = this.async();

        child_process.exec('appc acs publish --list_versions', function(error, stdout, stderr) {

            if (error !== null) {
                return grunt.fail.fatal(error);
            }

            var matches = stdout.match(REGEXP_VERSIONS);

            if (matches === null) {
                return done();
            }

            var all = matches[1].split(', ');
            var deployed = matches[2];

            if (all.length === 1) {
                return done();
            }

            async.each(all, function(version, callback) {

                if (version === deployed) {
                    return callback();
                }

                grunt.log.writeln('Unpublishing: ' + version);
                child_process.exec('appc acs unpublish --ver ' + version, callback);

            }, done);
        });

    });

    grunt.registerTask('publish', ['spawn:bump', 'unpublish', 'spawn:publish']);
    grunt.registerTask('prod', ['spawn:bump', 'unpublish', 'spawn:publish', 'nodemailer:deploy']);

    grunt.registerTask('default', 'publish');
};