ci: Add test matrix (Node 20, 22, 24 on Linux / macOS / Windows)

Also update checkout action to latest version.

Author: matz3

.github/workflows/reuse-compliance.yml

@@ -16,6 +16,6 @@ jobs:
     name: Compliance Check
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Execute REUSE Compliance Check
       uses: fsfe/reuse-action@v6

.github/workflows/security-audit.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout '${{ matrix.branch }}' branch
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           ref: ${{ matrix.branch }}
 

.github/workflows/test.yml

@@ -0,0 +1,36 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Unit and Integration
+    strategy:
+      fail-fast: false # Do not stop other jobs if one fails
+      matrix:
+        version: [20, 22, 24]
+        os: [ubuntu-24.04, windows-2025, macos-15]
+    runs-on: ${{ matrix.os }}
+    steps:
+
+    - uses: actions/checkout@v5
+
+    - name: Setup Node.js
+      uses: actions/setup-node@v6
+      with:
+        node-version: ${{ matrix.version }}
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Run unit tests
+      run: npm run unit

package.json

@@ -25,6 +25,7 @@
 	"scripts": {
 		"test": "npm run lint && npm run check-licenses && npm run depcheck && npm run coverage && npm run jsdoc-generate && npm run schema-generate && npm run generate-cli-doc",
 		"lint": "eslint ./ && npm run lint --workspaces",
+		"unit": "npm run unit --workspaces",
 		"coverage": "npm run coverage --workspaces",
 		"jsdoc": "npm run jsdoc-generate && open-cli site/api/index.html",
 		"jsdoc-generate": "node ./scripts/isWorkspace.js && npm run jsdoc-generate-workspace || npm run jsdoc-generate-local",