Update CI for Multi-Release JAR builds

Split CI into build (JDK 11) and test (JDK 8/11/17) jobs to support
module compilation while maintaining compatibility testing.

Author: cowwoc

.github/workflows/ci.yml

@@ -9,11 +9,8 @@ on:
       - main
 
 jobs:
-  test:
-    name: "JDK ${{ matrix.java }}"
-    strategy:
-      matrix:
-        java: [ 8, 11, 17 ]
+  build:
+    name: "Build with JDK 11"
     runs-on: ubuntu-latest
     steps:
       # Cancel any previous runs for the same branch that are still running.
@@ -30,21 +27,56 @@ jobs:
           key: maven-${{ hashFiles('**/pom.xml') }}
           restore-keys: |
             maven-
+      - name: 'Set up JDK 11'
+        uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165
+        with:
+          java-version: 11
+          distribution: 'zulu'
+      - name: 'Build Multi-Release JAR'
+        shell: bash
+        run: mvn -B process-test-classes -U -f build-pom.xml
+      - name: 'Upload build artifacts'
+        uses: actions/upload-artifact@v3
+        with:
+          name: build-artifacts
+          path: |
+            **/target/classes/
+            **/target/*.jar
+          retention-days: 1
+
+  test:
+    name: "Test on JDK ${{ matrix.java }}"
+    strategy:
+      matrix:
+        java: [ 8, 11, 17 ]
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: 'Check out repository'
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+      - name: 'Cache local Maven repository'
+        uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809
+        with:
+          path: ~/.m2/repository
+          key: maven-${{ hashFiles('**/pom.xml') }}
+          restore-keys: |
+            maven-
+      - name: 'Download build artifacts'
+        uses: actions/download-artifact@v3
+        with:
+          name: build-artifacts
       - name: 'Set up JDK ${{ matrix.java }}'
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165
         with:
           java-version: ${{ matrix.java }}
           distribution: 'zulu'
-      - name: 'Install'
-        shell: bash
-        run: mvn -B dependency:go-offline test clean -U --quiet --fail-never -DskipTests=true -f build-pom.xml
       - name: 'Test'
         shell: bash
-        run: mvn -B verify -U --fail-at-end -Dsource.skip=true -Dmaven.javadoc.skip=true -f build-pom.xml
+        run: mvn -B test -U --fail-at-end -f build-pom.xml
 
   publish_snapshot:
     name: 'Publish snapshot'
-    needs: test
+    needs: [build, test]
     if: github.event_name == 'push' && github.repository == 'google/auto'
     runs-on: ubuntu-latest
     steps:
@@ -75,7 +107,7 @@ jobs:
     permissions:
       contents: write
     name: 'Generate latest docs'
-    needs: test
+    needs: [build, test]
     if: github.event_name == 'push' && github.repository == 'google/auto'
     runs-on: ubuntu-latest
     steps: