Delete files in pipechain

[sindresorhus]

Delete files in pipechain

[adam-lynch]

See gulpjs/gulp#729

[sindresorhus]

What's the use-case?

[adam-lynch]

@sindresorhus I've a use case where I get files from a sitemap.xml (with gulp-sitemap-files) and delete them with del.

[sindresorhus]

Why can't you just assign it to a variable and use it in both del and gulp.src?

[adam-lynch]

I'm not sure what you mean. See gulpjs/gulp#729, how would you "assign it to a variable and use it in both del and gulp.src" there?

[kevva]

Yeah, that's not possible. I wouldn't make this module a gulp-plugin though. What is wrong with doing it your way?

[sindresorhus]

Off topic, but looking at your plugin it shouldn't be a gulp plugin, but rather a vinyl source plugin like vinyl-fs. Working on only one file in gulp.src is usually a sign you're doing something wrong.

As for this issue, what's wrong with doing like you're doing in your linked example? Except for wrong usage of map ofc. Use through2 instead.

[adam-lynch]

Working on only one file in gulp.src is usually a sign you're doing something wrong

Maybe I'd have multiple sitemaps though? Also, I don't know but there might be a use case where it needs to follow a pipe instead of just being a source (probably unlikely though).

Use through2 instead.

Cool

[kevva]

The problem @sindresorhus is describing with your plugin is that it shouldn't take a source. The basics of transform streams/write streams is that you should be able to pipe in whatever stuff you got.

By wrapping del inside through.obj you're essentially creating a transform stream (or "follow a pipe" as you describe it) so it's no difference from using any other gulp plugin. Make sure you include this.push(file) if you want to pipe the files to another plugin. E.g:

.pipe(through.obj(function (file, enc, cb) {
    this.push(file);
    del(file.path, cb);
}))
.pipe(somePlugin());

[demisx]

@sindresorhus My use case is being able to delete corresponding files from a build directory when a watched file was deleted in the app directory. For example, when a .coffee file is deleted, I capture deleted event in the stream and I need to delete corresponding .js and .js.map files in the build directory.

[demisx]

@kevva Thank you for sharing an approach. Though, it didn't work for me as is when I plugged it into the middle of my existing pipe chain. I had to reverse the order and push the file after calling del(), otherwise my next pipe would change the file object and del would try to operate on the wrong path. Not sure why yet, but this is what worked:

.pipe(through.obj(function(file, enc, cb) {
  del(file.path);
  this.push(file);
  cb();
}));

Perhaps this is more compliant with the gulp plugin guidelines:

Do not pass the file object downstream until you are done with it