build(ci): lint commits in pull requests

Prevent the merging of unconventional commits into the master branch.

Lint commits made directly onto the master branch.

Issues: #18

.github/workflows/build.yml

@@ -0,0 +1,46 @@
+---
+name: Build
+
+on:
+  pull_request: {}
+
+  push:
+    branches:
+      - master
+
+jobs:
+  commitlint:
+    name: Commit Lint
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out the codebase
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: ${{ github.event.pull_request.commits }}
+
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 21
+
+      - name: Install Node modules
+        run: npm install
+
+      - name: Check program versions
+        run: |
+          node --version
+          npm --version
+          npm run commitlint -- --version
+
+      - name: Validate last commit
+        if: github.event_name == 'push'
+        run: npm run commitlint -- --from HEAD~1 --to HEAD --verbose
+
+      - name: Validate commits in pull request
+        if: github.event_name == 'pull_request'
+        run: >-
+          npm run commitlint --
+          --from=${{ github.event.pull_request.head.sha }}~${{ github.event.pull_request.commits }}
+          --to=${{ github.event.pull_request.head.sha }}
+          --verbose

.husky/commit-msg

@@ -1,4 +1,4 @@
 #!/usr/bin/env sh
 . "$(dirname -- "$0")/_/husky.sh"
 
-npm run commitlint ${1}
+npm run lint-commit-msg ${1}

package.json

@@ -6,6 +6,7 @@
   },
   "scripts": {
     "prepare": "husky install",
-    "commitlint": "commitlint --edit"
+    "lint-commit-msg": "commitlint --edit",
+    "commitlint": "commitlint"
   }
 }