A line ending invariant alternative to hashFiles

Describe the enhancement Sometimes cached data is sufficiently cross-platform to be reused across runners on Windows and the Unix OSes. A problem arises if the cache key needs to be computed by hash-summing text files, which produces differing hash sums on the same file if it was e.g. checked out by git in text mode applying auto-conversion to the line endings.

This workflow run failed to hit the cache in the Windows test job, even though the preceding update-deps job on Linux had stored it.

Code Snippet It would be nice if a hashTextFiles function was available that would canonicalize line endings for the hash input:

  test:
    needs: update-deps
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest]
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v2
      - id: cargo-registry
        name: Restore cargo registry
        uses: actions/cache@v1
        with:
          path: ~/.cargo/registry
          key: cargo-registry-${{ hashTextFiles('**/Cargo.lock') }}

[mzabaluev]

Also consider using a .gitattributes file to control the line endings on windows

I’m not sure cargo would honor it when writing an updated lock file. More generally, forcing Unix-style endings on a file would inconvenience many developers just so a CI workflow can run correctly, which I think is not a good tradeoff.

[kriegaex]

A real-world use case for this is caching a local Maven repository, calculating the cache key from ${{ hashFiles('**/pom.xml') }}, which is a frequent use case in many projects. This yields one set of cache files for Linux and MacOS, but another one one Windows. As was discussed above, using .gitattributes and influence all users just so as to fix caching on CI is not an adequate solution, way too invasive.

See also:

• https://github.com/actions/cache/issues/614
• https://github.com/actions/checkout/issues/135