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Ormolu action

CI

This is Ormolu action that helps to ensure that your Haskell project is formatted with Ormolu. The action tries to find all Haskell source code files in your repository and fails if any of them is not formatted. In case of failure it prints the diff between the actual contents of the file and its formatted version.

Inputs

Windows

If you are running a workflow on Windows, be wary of Git's core.autocrlf. Ormolu always converts CRLF endings to LF endings which may result in spurious diffs, so you probably want to disable core.autocrlf:

$ git config --global core.autocrlf false

Example usage

In the simple case all you need to do is to add this step to your job:

- uses: haskell-actions/run-ormolu@v16

However, if you are using a matrix, then it is more efficient to have a separate job for checking of formatting:

jobs:
  ormolu:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: haskell-actions/run-ormolu@v16
  build:
    runs-on: ubuntu-latest
    needs: ormolu
    ...

Here, the build job depends on ormolu and will not run unless ormolu passes.

Example which commits the formatted files:

jobs:
  ormolu:
    runs-on: ubuntu-20.04
    steps:
      - uses: actions/checkout@v2
      - uses: haskell-actions/run-ormolu@v14
        with:
          mode: inplace
      - name: apply formatting changes
        uses: stefanzweifel/git-auto-commit-action@v4
        if: ${{ always() }}
        with:
          commit_message: automated ormolu commit