Use Gradle Wrapper if specified without Gradle version

[andersfischernielsen]

This will fix the bug described and confirmed in gradle/actions#33.

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This will use the available gradlew executable in order to allow post steps to clean up the cache as expected when the wrapper Gradle version is specified for the action.

[bigdaz]

Thanks for the PR. I'm a bit wary of this solution, since it assumes a Gradle project (with wrapper) is located in the root of the repository. So it wouldn't work for workflows like:

    - name: Setup Gradle
      uses: gradle/gradle-build-action@v2
      with:
        gradle-home-cache-cleanup: true

    - name: Execute Gradle build 1
      run: ./gradlew build
      working-directory: projects/gradle/proj-1

    - name: Execute Gradle build 2
      run: ./gradlew build
      working-directory: projects/gradle/proj-2

There's also the issue that you want a newer version of Gradle to perform the cleanup. Older versions will not properly cleanup the state generated by newer versions.

An alternative solution would be to auto-provision the latest version of Gradle to the PATH whenever gradle-home-cache-cleanup is enabled AND no gradle executable is found on the path.

[andersfischernielsen]

An alternative solution would be to auto-provision the latest version of Gradle to the PATH whenever gradle-home-cache-cleanup is enabled AND no gradle executable is found on the path.

This sounds like an optimal approach instead of assuming a wrapper project 😄

Given that we've set these in all our uses of the action and that the changes to get this done are nontrivial (especially in an unknown codebase) I'll close the PR.

But thanks for the helpful response! Nice to get an understanding of the behaviour we were seeing 🙏🏼