Gulp task executed by watch using cached config stream - gulp

Question

I'm trying use gulp to bundle and minify my files using gulp-bundle-assets. Running the tasks on their own is fine. My problem is using gulp.watch to watch for any changes in my config file and re-bundle my scripts.
The first time the watch executes everything works correctly. On successive occasions everything runs, but the exact same files are bundled - any changes in the config are ignored.
If I run my "bundle" task while the watch is running, "bundle" will use the current configuration. While successive watches will continue to use the configuration on the first execution.
My guess would be the data for the stream retrieved by gulp.src is cached. So how do I tell it to always get the latest version?
var gulp = require('gulp');
var bundle = require('gulp-bundle-assets');
var del = require('del');
var index = 0;
gulp.task('bundle', function () {
console.log('Bundling files ' + (index++));
return gulp.src('./bundle.config.js')
.pipe(bundle())
.pipe(gulp.dest('./bundles'));
});
gulp.task('watch', function () {
gulp.watch(['./scripts/**/*.{js,css}', './bundle.config.js'], ['clean', 'bundle']);
});
gulp.task('clean', function (cb) {
console.log('Cleaning files');
del(['./bundles/**/*'], cb);
});
An alternative I tried was to use watch(...).on, and calling gulp.run, but that didn't fix the problem, either. I also tried pasting the code from the bundle task in to the on callback, but still got the same result.

Answer 1

The culprit isn't gulp.src(), but bundle(). The gulp-bundle-assets plugin uses require() to load your bundle.config.js. Since Node.js caches return values from require() you always get the same config object after the file is loaded for the first time.
The solution is to invalidate the require cache in your bundle task:
var gulp = require('gulp');
var bundle = require('gulp-bundle-assets');
var del = require('del');
var index = 0;
gulp.task('bundle', ['clean'], function () { // run clean task before bundle task
// invalidate require cache for ./bundle.config.js
delete require.cache[require.resolve('./bundle.config.js')];
console.log('Bundling files ' + (index++));
return gulp.src('./bundle.config.js')
.pipe(bundle())
.pipe(gulp.dest('./bundles'));
});
gulp.task('watch', function () {
gulp.watch(['./scripts/**/*.{js,css}',
'./bundle.config.js'], ['bundle']); // only run bundle task
});
gulp.task('clean', function () {
console.log('Cleaning files');
return del(['./bundles/**/*']); // return promise object
});
Unrelated to your problem, but I also fixed your clean task. The way you had it set up didn't work.