Expand build matrix, e.g. run on MasOS

.github/workflows/main.yml

@@ -9,41 +9,27 @@ on:
       - '*'
 
 jobs:
-  check-gradle:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: 'Set up JDK'
-        uses: actions/setup-java@v4
-        with:
-          java-version: 8
-          distribution: temurin
-      - name: 'Init Gradle Build Action'
-        uses: gradle/gradle-build-action@v2
-        with:
-          # cache options only count for the first invocation
-          cache-read-only: ${{ github.ref != 'refs/heads/master' }}
-          arguments: --version
-      - name: 'Check Spock'
-        uses: gradle/gradle-build-action@v2
-        with:
-          arguments: check
   check-maven:
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, windows-latest, macOS-latest ]
+        javaVersion: [ 8, 21 ]
+        javaDist: [ temurin ]
+    runs-on: { { matrix.os } }
     steps:
       - uses: actions/checkout@v4
       - name: Cache local Maven repository
         uses: actions/cache@v4
         with:
           path: ~/.m2/repository
-          key: test-${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
+          key: test-${{ matrix.os }}-maven-${{ hashFiles('**/pom.xml') }}
           restore-keys: |
-            test-${{ runner.os }}-maven-
-      - name: 'Set up JDK'
+            test-${{ matrix.os }}-maven-
+      - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          java-version: 8
-          distribution: temurin
+          java-version: ${{ matrix.javaVersion }}
+          distribution: ${{ matrix.javaDist }}
       - name: 'Check Spock'
         run: |
           ./mvnw -V -B verify