javascript - Iterating over directories with Gulp?

Question

I'm new to gulp, but I'm wondering if its possible to iterate through directories in a gulp task.

Here's what I mean, I know a lot of the tutorials / demos show processing a bunch of JavaScript files using something like "**/*.js" and then they compile it into a single JavaScript file. But I want to iterate over a set of directories, and compile each directory into it's own JS file.

For instance, I have a file structure like:

/js/feature1/something.js
/js/feature1/else.js
/js/feature1/foo/bar.js
/js/feature1/foo/bar2.js
/js/feature2/another-thing.js
/js/feature2/yet-again.js

...And I want two files: /js/feature1/feature1.min.js and /js/feature2/feature2.min.js where the first contains the first 4 files and the second contains the last 2 files.

Is this possible, or am I going to have to manually add those directories to a manifest? It would be really nice to pragmatically iterate over all the directories within /js/.

Thanks for any help you can give me.

-Nate

Edit: It should be noted that I don't only have 2 directories, but I have many (maybe 10-20) so I don't really want to write a task for each directory. I want to handle each directory the same way: get all of the JS inside of it (and any sub-directories) and compile it down to a feature-based minified JS file.

Answer 1

There's an official recipe for this: Generating a file per folder

var fs = require('fs');
var path = require('path');
var merge = require('merge-stream');
var gulp = require('gulp');
var concat = require('gulp-concat');
var rename = require('gulp-rename');
var uglify = require('gulp-uglify');

var scriptsPath = 'src/scripts';

function getFolders(dir) {
    return fs.readdirSync(dir)
      .filter(function(file) {
        return fs.statSync(path.join(dir, file)).isDirectory();
      });
}

gulp.task('scripts', function() {
   var folders = getFolders(scriptsPath);

   var tasks = folders.map(function(folder) {
      return gulp.src(path.join(scriptsPath, folder, '/**/*.js'))
        // concat into foldername.js
        .pipe(concat(folder + '.js'))
        // write to output
        .pipe(gulp.dest(scriptsPath)) 
        // minify
        .pipe(uglify())    
        // rename to folder.min.js
        .pipe(rename(folder + '.min.js')) 
        // write to output again
        .pipe(gulp.dest(scriptsPath));    
   });

   // process all remaining files in scriptsPath root into main.js and main.min.js files
   var root = gulp.src(path.join(scriptsPath, '/*.js'))
        .pipe(concat('main.js'))
        .pipe(gulp.dest(scriptsPath))
        .pipe(uglify())
        .pipe(rename('main.min.js'))
        .pipe(gulp.dest(scriptsPath));

   return merge(tasks, root);
});