Improve check-theme-changes job

[szepeviktor]

1. Use actions/checkout action to fetch
2. Use git diff --quiet to decide whether there were changes

📜 https://git-scm.com/docs/git-diff

--prune is added by default
https://github.com/actions/checkout/blob/8ade135a41bc03ea155e62e844d188df1ea18608/src/git-command-manager.ts#L257

[codepuncher]

Hi @szepeviktor,

Thanks for your PR!
It's appreciated; looks a better approach.

I'm not sure there is an easy way to test this before merging due to nature of refs with GitHub Actions.
Do you have any idea/suggestion?

[szepeviktor]

I'm not sure there is an easy way to test this before merging

Yes, there is. You can test it in a fork.

[codepuncher]

Hi @szepeviktor
Thanks again for the PR.

I have just tested it in the https://github.com/ItinerisLtd/.github/compare/test-patch branch so I can use it in one of our projects.
Unfortunately it is always skipping php-style-check and build-production-assets even if a change is made.

[szepeviktor]

Thank you for testing.
Could you add this before the if and see its output?

git diff --diff-filter=ACMRT origin/${{ github.event.repository.default_branch }} HEAD -- web/app/themes/${{ inputs.THEME_NAME }}

[codepuncher]

There is no output.
Assume this is because we are only fetching main using ref: ${{ github.event.repository.default_branch }}

[szepeviktor]

I see! The original code only fetches github.event.repository.default_branch but does not check it out.