How to properly cache Rector cache in Github Actions?

[CanVuralStudocu]

Hello,

Documentation recommends this cache key ${{ runner.os }}-rector-${{ hashFiles('**/composer.lock') }} to be used in Github Actions.

But this cache key only depends on the changes of composer.lock files. Does not change with the actual code file changes. For example if a new file is added or removed from the codebase, Rector cache would not be aware of that.

Does anyone use a different cache key? Like a key created from the all files in a directory or something?

[ondrejmirtes]

The only problem with that cache key is that it doesn’t get updated so the cache makes less and less sense over time until it’s invalidated thanks to composer.lock being updated.

You can use a trick in GitHub Actions that:

1. will update the cache every time
2. will find the correct latest cache

the trick is to have a unique key each time, by appending run ID to the end, and then have the common prefix in restore-keys.

Like mentioned here (also applies to PHPStan’s result cache): https://staabm.github.io/2023/10/21/phpstan-result-cache-gotchas.html

[CanVuralStudocu]

Ooh that makes sense. I didn't understand what restoreKeys was doing before. But it makes sense!

I'll try this. Thanks.

[scollovati]

The documentation was updated with this suggestion

      - name: Rector Cache
        uses: actions/cache@v3
        with:
          path: ./var/cache/rector
          key: ${{ runner.os }}-rector-${{ github.run_id }}
          restore-keys: ${{ runner.os }}-rector-

      - name: Rector Dry Run
        run: php vendor/bin/rector process --dry-run --config=rector.php

However, I get this error [ERROR] Failed to create "./var/cache/rector": mkdir(): Permission denied in the second step (i.e. when running rector).

[samsonasik]

@scollovati you may need to create a directory './var/cache/rector` first on ci process, /cc @staabm this may need to be mentioned in doc?

[samsonasik]

@scollovati documentation updated https://getrector.com/documentation/cache-in-ci , could you verify if it works? thank you.

[scollovati]

Thanks, but in that case the cache folder is not so useful when developing locally since the /tmp folder is cleared. I am trying to verify if the OS ENV vars that Github Action sets are available also in the PHP CLI. If yes, by simply checking $_ENV['GITHUB_ACTIONS'] we could make the cache working meaningfully both locally and in the CI.