A GitHub Action to fail builds whos files have both upper and lower case mixed, i.e. camelCase to prevent filename conflicts and broken deployments.

• Suggests kebab-case fixes of problem filenames for quicker fixing
• No dependencies* - to avoid supply chain security issues.
• Ignores common mixed case files that usually won't "break" builds, e.g. CONTRIBUTING.md

*Note: GitHub Actions Toolkit is still required for JavaScript based actions.

steps:
  - name: Checkout
    uses: actions/checkout@v2

  - name: Lint Filenames
    uses: julie-ng/lowercase-linter@v1
    id: lint_filenames
    continue-on-error: true
    with:
      path: '.'
      pr-comment: true
      repo-token: ${{ secrets.GITHUB_TOKEN }}

Use the pr-comment param to toggle whether you want suggested renames added to a pull request.

• path (optional)

  Path to scan for mixed case filenames. Will search subfolders too.
  Default: .

• pr-comment (optional)

  If file name errors are found, suggested fixes are posted to the Pull Request.
  Default: false

• repo-token (optional)

  GitHub Action workflow token needed to add comments to pull requests.
  Default: ''

• errors

  Array - list of files with mixed case and suggested renames in JSON.

• linted

  Array - list of all files that were checked for mixed case names.

• comment-url

  String - URL of the comment posted to Pull Request (if errors were found).

If a system is case sensitive, then README.md and readme.md can co-exist.

If a system is not case sensitive, then Logo.png can be referenced both as its actual mixed case name and all lowercase logo.png. So if you have <img src="logo.png"> but your image is actually named Logo.png, it will work locally but users will see a broken image when deployed to a Linux based server.

Not deploying? Still a problem for colleagues. If you're collaborating and someone checks in a file with mixed case, it can be a nightmare to resolve because you have to do it in 2 places - OS and git. And if people don't keep their branches up to date, the mixed files come back like a recurring nightware 😵‍💫

If you check the output, the action will also make suggestions using the kebab-case naming convention, for example:

MIT