Gulp task to delete empty files

Question

When compiling TypeScript, I get a lot of empty JavaScript files generated because their TypeScript counterparts contain only interfaces. There's currently no tsc option to suppress generation of these files. I'm using the gulp-tsc plugin to compile.

Is there a plugin or some other means to clean up empty files, or even a more general purpose gulp plugin that would allow me to delete files based on their name and content? Or is there a way to do this in gulp without using plugins?

Answer 1

I think you could relatively easily use node-glob to look for matching files outside gulp, something like this:

var glob = require('node-glob'),
    fs = require('fs);

gulp.task('delete-empty-files', function(cb) {
    glob('/path/to/generated/**/*.js', function(err, files) {
        files.forEach(function(file) {
            if(fs.statSync(file).size === 0) {
                fs.unlinkSync(file);
            }
        });
        // make sure the task runs asynchronously!
        cb();
    });
});

Alternatively, you could use gulp-tap to achieve a similar result, like so:

var tap = require('gulp-tap'),
    fs = require('fs);

gulp.task('delete-empty-files', function() {
    return gulp.src('/path/to/generated/**/*.js')
        .pipe(tap(function(file) {
            if(file.stat.size === 0) {
                fs.unlinkSync(file);
            }
        });
    });
});

They're pretty equal, really. I think the first one will be faster, because it won't have the extra stuff from gulp and vinyl-fs.

You might be able to add the {read: false} options to gulp.src() to speed things up, but that might also disable the .stat from being read. If you want to try it, you add it like this:

return gulp.src('/path/to/files/**/*.js', {read: false}).pipe(...)

Answer 2

A better answer would be to just name those interface files with the .d.ts extension instead of .ts. No files are generated this way.

Answer 3

Alternatively, for anyone else facing similar issues, gulp-clip-empty-files solves this.

Remove empty files from stream. This prevent errors on some other plugins like gulp-sass and can be usefull removing placeholders.

The usage is quite simple...

var gulp = require('gulp');
var clip = require('gulp-clip-empty-files');

gulp.task('default', function () {
    return gulp.src('src/*.scss')
        .pipe(clip())
        .pipe(gulp.dest('dist'));
});

In this example all empty .scss files will be "clipped" (ignored?) before written out