Gulp.js event stream merge order

Question

I am trying to merge css and scss files into a main.css file that goes in my build directory. Its working, but not in the right order. The style attributes from the scss files n

Answer 1

I failed with all provided answers, they produced some silent errors. Finally merge2 worked for me (seems like there was gulp-merge and later the project was renamed into merge2). I'm not sure why there is a need in streamify plugin, e.g. streams created with Rollup may produce "stream-not-supported-errors" with gulp-concat, gulp-uglify or gulp-insert.

const mergeStreams = require('merge2');
const streamify = require('streamify');
...
gulp.task('build', () => {
    const streams = sources.map(createJSFile);
    return mergeStreams(...streams)
        .pipe(streamify(concat('bundle.js')))
        .pipe(streamify(uglify()))
        .pipe(gulp.dest('./dist'));
});