Checkmate - A flake checker (treefmt & nix-unit) for testing other flakes with zero dependencies.

Checks include:

• treefmt - nixfmt, deadnix, mdformat, yamlfmt. See treefmt.nix.

• nix-unit - The flake being checked (ie, inputs.target) is expected to expose flakeModules.checkmate:

See import-tree or example

# Generate a new project including github CI action
nix flake new -t github:vic/checkmate

Running treefmt on your code

# formatting your code
nix run path:checkmate#fmt

# checking if code is formatted
nix run path:checkmate#fmt -- --ci

Running flake check locally

nix run path:checkmate

CI Usage

On your github action:

on:
  pull_request:
  push:
    branches: [main]
jobs:
  flake-check:
    name: nix flake check
    runs-on: ubuntu-latest
    steps:
      - uses: cachix/install-nix-action@v30
      - run: nix flake check -L github:vic/checkmate --override-input target github:$GITHUB_REPOSITORY/
$GITHUB_SHA

As a fully working example, see:

https://github.com/vic/import-tree