ci: Add Conventional Commits linter for CI

.github/workflows/commit-linter.yaml

@@ -0,0 +1,38 @@
+name: commit-linter
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  commit-lint:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: cachix/install-nix-action@v25
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+
+      - name: npm install
+        run: nix develop --command npm install --include=dev
+
+      - name: Print versions
+        run: |
+          git --version
+          node --version
+          npm --version
+          npx commitlint --version
+
+      - name: Validate current commit (last commit) with commitlint
+        if: github.event_name == 'push'
+        run: nix develop --command npx commitlint --last --verbose
+
+      - name: Validate PR commits with commitlint
+        if: github.event_name == 'pull_request'
+        run: nix develop --command npx commitlint --from ${{ github.event.pull_request.head.sha }}~${{ github.event.pull_request.commits }} --to ${{ github.event.pull_request.head.sha }} --verbose

commitlint.config.mjs

@@ -0,0 +1,6 @@
+export default { 
+    extends: ['@commitlint/config-conventional'],
+    rules: {
+        'subject-case': [2, 'always', 'sentence-case'] // override default
+    }
+};

flake.nix

@@ -36,6 +36,7 @@
           buildInputs = [
           discretization
           pkgs.python310Packages.pytest # Adding pytest here so that developers can run the tests.
+          pkgs.nodejs_20 # To run commitlint
           ];
         };
         packages.default = discretization;

package.json

@@ -0,0 +1,6 @@
+{
+  "devDependencies": {
+    "@commitlint/cli": "^19.3.0",
+    "@commitlint/config-conventional": "^19.2.2"
+  }
+}