hashFiles() does not work for valid patterns

The expected behavior is that all three of the following steps pass on all platforms:

- name: Cache **/README.md
  uses: actions/cache@preview
  with:
    path: .
    key: test-${{ runner.os }}-${{ hashFiles('**/README.md') }}
  continue-on-error: true

- name: Cache README.md
  uses: actions/cache@preview
  with:
    path: .
    key: test-${{ runner.os }}-${{ hashFiles('README.md') }}
  continue-on-error: true

- name: Cache *README.md
  uses: actions/cache@preview
  with:
    path: .
    key: test-${{ runner.os }}-${{ hashFiles('*README.md') }}
  continue-on-error: true

But right now hashFiles(README.md) and hashFiles(*README.md) fails macOS:

2019-11-02T18:08:19.8057240Z ##[error]The template is not valid. 'hashFiles(README.md)' failed. Search pattern 'README.md' doesn't match any file under '/Users/runner/runners/2.160.0/work/github-actions-hashfiles-test/github-actions-hashfiles-test'
2019-11-02T18:08:19.8346580Z ##[error]The template is not valid. 'hashFiles(*README.md)' failed. Search pattern '*README.md' doesn't match any file under '/Users/runner/runners/2.160.0/work/github-actions-hashfiles-test/github-actions-hashfiles-test'

And hashFiles(README.md) and hashFiles(**/README.md) fails Windows:

2019-11-02T18:09:01.2005576Z ##[error]The template is not valid. 'hashFiles(**/README.md)' failed. Search pattern '**/README.md' doesn't match any file under 'd:\a\github-actions-hashfiles-test\github-actions-hashfiles-test'
2019-11-02T18:09:01.2212553Z ##[error]The template is not valid. 'hashFiles(README.md)' failed. Search pattern 'README.md' doesn't match any file under 'd:\a\github-actions-hashfiles-test\github-actions-hashfiles-test'

See example repo: https://github.com/poiru/github-actions-hashfiles-test And run: https://github.com/poiru/github-actions-hashfiles-test/commit/23dcdc7705d1660ba845291f744dd9b4a9157458/checks?check_suite_id=293065410

[joshmgross]

hashFiles will be updated soon so that relative paths are rooted at github.workspace, which will allow hashFiles('README.md').

/ not working on Windows is definitely a bug, ideally / would work on all platforms so that you wouldn’t need a runner.separator variable.

[stomar]

@joshmgross The current hashFiles documentation states: “Returns a single hash for the set of files that matches the path pattern. The path is relative to the GITHUB_WORKSPACE directory […]” (as of 2019-11-09).

However, hashFiles('Gemfile.lock') does not work at the moment. Documentation error or do I misunderstand something?