Allow specifying diff program

[sirn]

On some systems such as OpenBSD, the diff program does not support some of the features available under GNU diff, e.g. --strip-trailing-cr. AFAIK, there's no way to reproduce the behavior of --strip-trailing-cr without piping to tr or sed (which is probably not ideal).

So I think it might make sense to allow specifying diff program, so I can install gdiff and configure prettier-emacs to use it. This PR basically add prettier-js-diff-command to defcustom, and use it in place of the existing diff string.

Thanks!

[Aankhen]

This would be very useful to have.

[Copilot]

Pull Request Overview

This PR allows users to specify a custom diff program, which is especially useful on systems where GNU diff options (e.g. --strip-trailing-cr) are unavailable. The changes include adding a new customizable variable (prettier-js-diff-command) and updating the call-process-region invocation to use this variable instead of a hardcoded "diff" command.

Comments suppressed due to low confidence (2)

prettier-js.el:57

• Consider clarifying the docstring to indicate that this variable can be set to alternative diff programs (e.g. 'gdiff') on systems where GNU diff is not available.

(defcustom prettier-js-diff-command "diff"

prettier-js.el:194

• Since non-GNU diff tools might not support the '--strip-trailing-cr' argument, consider adding a note in the documentation or making this argument configurable for different diff tools.

                 (call-process-region (point-min) (point-max) prettier-js-diff-command nil patchbuf nil "-n" "--strip-trailing-cr" "-"

[fisker]

@jacksonrayhamilton

[jacksonrayhamilton]

Good idea, this will improve cross-platform compat. It might also be nice if we had a note in the README directing BSD users to customize this. However, the code change is already fine, so I'm approving it.