chore(gulp): use Gulp async task support and Karma API properly

[danielpacak]

[danielpacak]

Hej Mistrzowie! Ktoś to zmerdżuje?

[carlthuringer]

:+1: This is exactly what I needed to solve my issue with using the supplied examples in a CI environment.

[JoniJnm]

It still has problems. The server.start() kills the proccess when it ends (I don't know why)

gulp.task('test', function(done) {
    var server = new karma.Server({
        configFile: __dirname + '/test/karma.config.js',
        singleRun: true
    });

    server.on('run_complete', function (browsers, results) {
        if (results.error || results.failed) {
            done(new Error('There are test failures'));
        }
        else {
            done();
        }
    });

    server.start();
});

gulp.task('js', ['test'], function() {
    return gulp.src('app/**/*.js')
        .pipe(uglify())
        .pipe(gulp.dest('public/js'));
});

The output (js task doesn't end):

user@vm:/var/www/test# gulp js
[12:02:56] Using gulpfile /var/www/test/gulpfile.js
[12:02:56] Starting 'test'...
DEPRECATED: use your own version of lodash, this will go away in [email protected]
DEPRECATED: use your own version of lodash, this will go away in [email protected]
13 07 2016 12:02:56.898:INFO [karma]: Karma v1.1.1 server started at http://localhost:8080/
13 07 2016 12:02:56.901:INFO [launcher]: Launching browser PhantomJS with unlimited concurrency
13 07 2016 12:02:56.908:INFO [launcher]: Starting browser PhantomJS
13 07 2016 12:02:57.212:INFO [PhantomJS 2.1.1 (Linux 0.0.0)]: Connected on socket /#U1iVuy2DZhVyemxmAAAA with id 18916034
 PhantomJS 2.1.1 (Linux 0.0.0): Executed 1 of 1 SUCCESS (0.047 secs / 0.001 secs)
.
PhantomJS 2.1.1 (Linux 0.0.0): Executed 1 of 1 SUCCESS (0.047 secs / 0.001 secs)
[12:02:57] Finished 'test' after 1.05 s
[12:02:57] Starting 'js'...
user@vm:/var/www/test#

I had to run the test in a child

gulp.task('test', function(done) {
    var child_process = require('child_process');
    child_process.exec('karma start test/karma.config.js', function (err, stdout){
        gutil.log(stdout);
        if (err) {
            throw new Error('There are test failures');
        }
        else {
            done();
        }
    });
});

[danielpacak]

I'll have a look at this PR once again. It's been created a while ago and there're some changes in Karma and my understanding of Gulp.

[deltamualpha]

The example in the README.md was precisely what I needed to fix a delayed-timeout issue; it'd be nice to get that merged so it's easier to find when debugging that issue.

[johannesjo]

@danielpacak if I use your solution inside of a task chain no tasks will be executed after the karma task is finished, as process.exit is being called by karma, if you provide no done callback as second parameter.