How to zip up zip files using Gulp Zip

I've started using Gulp JS and must admit I'm finding it really useful.

One of the tasks I need to perform is zip up a collection of folders into individual zip files, one for each folder and then zip all this zipped files up into one single zip file. Using Gulp-Zip I've managed to get this far:

var modelFolders = [
        'ELFH_Check',
        'ELFH_DDP',
        'ELFH_Free'
];

gulp.task('zipModels', function () {

        for (var i = 0; i < modelFolders.length; i++) {

            var model = modelFolders[i];

            gulp.src('**/*', {cwd: path.join(process.cwd(), '/built_templates/' + model) })
            .pipe(zip(model + '.zip'))
            .pipe(gulp.dest('./built_templates'));

        };

});

This works and outputs ELFH_Check.zip, ELFH_DDP.zip and ELFH_Free.zip. However, I then need to zip up these zip files into one zip file called "Templates.zip" and I've not managed to get this task to work:

// zip up model files
gulp.task('zipTemplate', ['zipModels'], function () {  

        gulp.src('*.zip', {cwd: path.join(process.cwd(), './built_templates/') })
               .pipe(zip('Templates_.zip'))
               .pipe(gulp.dest('./built_templates'));

});

Does anyone know if this is possible or what I'm doing wrong?

Solution

~~I saw the problem as well, and it seems to be related to the cwd option somehow. I'll investigate further.~~

After @OverZealous comment, I investigated further and found two issues:

As he said, you need to hint gulp to wait until the end of the dependency task (zipModels), by returning a stream from it. As you have multiple streams, you can use event-stream.merge to return a bundle stream.
The reason why the bundle zip wouldn't work, is because you cwd points to /built_templates/, and the second slash is causing some problem. To work properly, you need to remove the trailing slash, so it should be path.join(process.cwd(), '/built_templates').

IMPORTANT

Anyway, you should avoid temporary files. Gulp philosophy is to try using pipes to avoid IO. In that direction, what you want to do is to cut the intermediary dest steps, merge the streams, zip them, and finally, output them.

Something like that:

var es = require('event-stream');

var modelFolders = [
    'ELFH_Check',
    'ELFH_DDP',
    'ELFH_Free'
];

gulp.task('zipModels', function () {
    var zips = [],
        modelZip;

    for (var i = 0; i < modelFolders.length; i++) {
        var model = modelFolders[i];

        modelZip = gulp.src('**/*', {cwd: path.join(process.cwd(), '/built_templates/' + model) })
          .pipe(zip(model + '.zip'));

        // notice we removed the dest step and store the zip stream (still in memory)
        zips.push(modelZip);
    };

    // we finally merge them (the zips), zip them again, and output.
    return es.merge.apply(null, zips)
        .pipe(zip('templates.zip'))
        .pipe(gulp.dest('./'));
});

By the name of your folder (built_templates), it seems you have some other task that will generate the temporary built files. Preferably, you don't want these as well. You should pipe their streams directly to the ZIP stream, a finally, to the bundle-zip stream. By doing that, you would have a simple stream flow, with one disk read, and one disc write at the end, with no temporary files.

If you need them to be different tasks, consider having a function that will generate the stream up to the step before the gulp.dest pipe, and use this function on all subtasks.

Additionally, always try to hint your async tasks by returning a stream, a promise or receiving a callback function, and advise the end of the task.