prettier-js-mode reformats file even when file is in .prettierignore

[tamouse]

I have the following in my emacs init.el:

(use-package prettier-js 
  :ensure t
  :config
  (add-hook 'web-mode-hook
	    #'(lambda ()
		(enable-minor-mode
		 '("\\.jsx?\\'" . prettier-js-mode)
		 ))
	    )
  (add-hook 'rjsx-mode-hook 'prettier-js-mode)
  )

In a project, I have this for .prettierignore:

*.spec.js
*.test.js

When I visit a file, src/score_to_grade.spec.js, it shows Prettier in the mode line, but on save, it reformats the file.

I seems that it's ignoring the ignore settings?

Additionally, if I use // prettier-ignore-start ... // prettier-ignore-end these are also not respected and the code between them is formatted in emacs prettier-js-mode.

If I run prettier from my terminal, both of these work as expected.

Versions:

• Emacs: GNU Emacs 26.2
• prettier-js: 20180109.726
• prettier: 1.19.1 (latest)

[rtm]

Is there any known workaround for this issue, or any update?

[rtm]

// prettier-ignore-{start,end} don't work for me in JS files at least even from the command line. I don't think this features is defined to work for JavaScript. // prettier-ignore does work, though. Therefore, I think there are two separate problems happening here.

[rtm]

The problem with .prettierignore is that internally this mode copies the file into a temporary buffer and then applies prettier to that, so of course the filenames do not match. I'm not quite sure why it would be doing that. Wouldn't it be good enough to just execute prettier in place with the --write option?

[jacksonrayhamilton]

Hi guys, sorry no one was able to get back to you in the long time since this discussion started.

The problem with .prettierignore is that internally this mode copies the file into a temporary buffer and then applies prettier to that, so of course the filenames do not match.

That was a reasonable theory, but I don't believe it was the source of the issue. This package uses the --stdin-filepath CLI flag which should inform Prettier about the original filename. Prettier has a test confirming that the CLI-provided filename is compared against the ignore file: https://github.com/prettier/prettier/blob/3.6.2/tests/integration/__tests__/stdin-filepath.js#L131-L138

In fact, I do find that my .prettierignore is picked up by this package, but only when I'm editing a file in the same directory as my .prettierignore. If I edit a file in a subdirectory, then it's not respected.

If you run the prettier command via a terminal from the same directory as .prettierignore, then it's respected. And if you cd to a subdirectory, it's not.

So I believe the main issue is the directory from which the prettier command is being launched from. Actually, this has been reported as an issue upstream: prettier/prettier#12923

In this package, prettier is launched from whatever default-directory is, which defaults to the directory of the file you're editing. One possible solution is that this package could try and compensate for Prettier's (probably wrong) behavior here, by searching upwards for .prettierignore and binding default-directory to the .prettierignore directory. However, I feel like this should just be fixed upstream.

[jacksonrayhamilton]

I see a few possible solutions:

1. This package could resolve the .prettierignore path, and either bind default-directory, or provide the .prettierignore path as the --ignore-path value. And do the same for .gitignore, I suppose, since that's also supported. As you can imagine, this kind of solution likely has to keep pace with upstream changes to ignoring and complexities around the process.
2. Implement ignore file resolution (for .prettierignore, .gitgnore) in Prettier, so it can handle resolution in the same way as it does for .prettierrc config files - although this would have merge conflicts with the PR I'll mention in "3."
3. Instead of using .prettierignore, users could use a new ignores config property that's been desired for a while (see: prettierIgnore key in package.json? prettier#3460, config option to ignore paths prettier#4708) and implemented (in: feat: add ignores on .prettierrc files and package.json prettier#16286). Prettier config files are already properly resolved from subdirectories, which solves the present issue, for users who migrate. Also, having ignores in the config file has the advantage of consolidating files and making configs more reusable.

Personally, I think a good starting point would be to get prettier/prettier#16286 merged; the code is already written, so it's the most immediate solution to the problem. cc @fisker PTAL!

After that's in - such that there's no more concern about merge conflicts - then we could talk about implementing .prettierignore resolution in Prettier, if not just for completeness' sake for the people who still use those files.