Provide better DX when creating patches

[sc0rp10]

Verification

• I have updated Composer to the most recent stable release (composer self-update)
• I have updated Composer Patches to the most recent stable release (composer update cweagans/composer-patches)
• I am using one of the supported PHP versions (8.0+)
• I have searched existing issues and discussions for my idea.

Is your feature request related to a problem?

Hello!

I've been using this library for quite a while. I don't need to create patch files very often, but every time I do, it's a pretty painful experience. I always struggle with the patch format (which doesn't feel very intuitive to me), line numbers, file paths (which are relative to the vendor directory), and the overall testing flow.

Describe your proposed solution(s)

Have you considered providing a more developer-friendly way to create patches?

I imagine it as a simple console command that guides the developer through the process, for example:

• Enter a patch name
• Select a source file
• The tool prints a temporary destination path to edit
• The tool compares the source and destination and generates a patch
• The patch file header is fixed automatically
• Confirm whether to save the patch
• Save the patch after confirmation

This is just a rough draft, but the general idea is to have a wizard-style workflow that helps developers create patches without having to manually deal with all the low-level details.

What do you think about it?

Describe alternatives

No response

Additional context

No response

[github-actions]

👋 Thanks for the idea! Please remember that this is an open source project - feature requests may or may not be implemented, and if they are, the timeline is unknown. If you need a guaranteed implementation or timeline, sponsorships are welcome!

[cweagans]

I think part of the problem is that you're trying to create patches inline in the parent project. That is, if your project depends on e.g. symfony/process, it's better to git clone https://github.com/symfony/process, check out whatever branch/tag you're using, edit there, and then git diff > mypatch.patch. Then, mypatch.patch can be moved into your project and added to your composer.json/patches.json - you don't have to change the header at all.

Composer Patches is primarily for applying patches to dependencies. I'm not sure if the process of generating the patches belongs in this project, but if you end up building that in a separate Composer plugin, I'd be happy to add a docs page here that links off to related projects!

Leaving this open for further discussion for now.

[avioli]

@sc0rp10 A year late, but I needed a similar functionality for a simple Drupal module's info.yaml version fix:

# since this is a Drupal project - go into the module's dir
cd web/modules/contrib/<module>

# then init a git repo and add all existing files to it
git init .
git add .

# edit whatever file or files I need with my editor of choice
vim module.info.yaml

# generate the patch file to my patches directory
git diff > ../../../../patches/whatever-module-path/fix-of-some-kind-for-module.patch

# cleanup temporary git repo
rm -rf .git/

# go back to project level so I can apply the patch
cd ../../../../

Then add that patch path (aka "url") to your patch-file or however you deal with patches and apply it.

The bottom line is that your best bet is to use git itself to create the patch, but since modules are not carrying all their git history - you need to init a repo temporarily, then remove it once your patch is created.

You don't need to "undo" your changes, since the patch will re-install the dependency. Theoretically you don't need to remove the temporary .git, but just in case, since git will consider this a submodule.

You could even convert these steps into a script if you have to do this often enough.