use toolchains to test against multiple JDKs

* build only on 17
* tests also on 21, 22, 23
* drop usage of github actions matrix

Author: fprochazka

.github/workflows/gradle-build.yml

@@ -11,25 +11,29 @@ env:
 
 jobs:
   gradle:
-    strategy:
-      matrix:
-        java: [17, 21, 22, 23]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
 
       - name: Setup Java
         uses: actions/setup-java@v4
         with:
-          distribution: temurin
-          java-version: ${{ matrix.java }}
+          distribution: 'temurin'
+          java-version: | # the last one is default
+            23
+            22
+            21
+            17
           cache: gradle
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
         with:
           add-job-summary-as-pr-comment: on-failure
 
+      - name: Gradle toolchains info
+        run: ./gradlew -q javaToolchains
+
       - name: Gradle build environment info
         run: ./gradlew -q buildEnvironment
 
@@ -41,6 +45,8 @@ jobs:
         if: always() # always run even if the previous step fails
         with:
           name: junit-test-results
-          path: '**/build/test-results/test/TEST-*.xml'
+          path: |
+            **/build/test-results/test/TEST-*.xml
+            **/build/test-results/test-jdk*/TEST-*.xml
           retention-days: 1
           overwrite: true

.github/workflows/publish-test-results.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download Test Report
-        uses: dawidd6/action-download-artifact@6
+        uses: dawidd6/action-download-artifact@9
         with:
           name: junit-test-results
           workflow: ${{ github.event.workflow.id }}

buildSrc/src/main/kotlin/framefork.java.gradle.kts

@@ -22,6 +22,10 @@ repositories {
 java {
     sourceCompatibility = JavaVersion.VERSION_17
     targetCompatibility = JavaVersion.VERSION_17
+
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
 }
 
 kotlin {
@@ -63,28 +67,6 @@ idea {
     }
 }
 
-tasks.withType<JavaCompile>() {
-    doLast {
-        javaCompiler.getOrNull()?.also {
-            println("Used JDK: ${it.metadata.javaRuntimeVersion} ${it.metadata.vendor}")
-        }
-    }
-}
-
-tasks.withType<Test> {
-    useJUnitPlatform()
-
-    testlogger {
-        showExceptions = true
-        showStackTraces = true
-        showFullStackTraces = true
-        showCauses = true
-        showPassedStandardStreams = false
-        showSkippedStandardStreams = false
-        showFailedStandardStreams = true
-    }
-}
-
 nullaway {
     annotatedPackages.add("org.framefork")
 }
@@ -181,6 +163,12 @@ tasks.withType<JavaCompile> {
             "com.github.rvesse.airline.annotations.Option"
         ))
     }
+
+    doLast {
+        javaCompiler.getOrNull()?.also {
+            println("Used JDK: ${it.metadata.javaRuntimeVersion} ${it.metadata.vendor}")
+        }
+    }
 }
 
 tasks.withType<Javadoc> {
@@ -189,7 +177,47 @@ tasks.withType<Javadoc> {
 }
 
 tasks.named("test") {
+    description = "Runs the unit tests against the default JDK"
+}
+
+for (javaVersion in listOf(21, 22, 23)) {
+    val testTask = tasks.register<Test>("test-jdk${javaVersion}") {
+        group = "Verification"
+        description = "Runs the unit tests against JDK $javaVersion"
+
+        javaLauncher.set(javaToolchains.launcherFor {
+            languageVersion.set(JavaLanguageVersion.of(javaVersion))
+        })
+
+        testClassesDirs = sourceSets.test.get().output.classesDirs
+        classpath = sourceSets.test.get().runtimeClasspath
+    }
+
+    tasks.named("check") {
+        dependsOn(testTask)
+    }
+}
+
+tasks.withType<Test>() {
     outputs.upToDateWhen { false }
+
+    useJUnitPlatform()
+
+    testlogger {
+        showExceptions = true
+        showStackTraces = true
+        showFullStackTraces = true
+        showCauses = true
+        showPassedStandardStreams = false
+        showSkippedStandardStreams = false
+        showFailedStandardStreams = true
+    }
+
+    doFirst {
+        javaLauncher.getOrNull()?.also {
+            println("Using JDK: ${it.metadata.javaRuntimeVersion} ${it.metadata.vendor}")
+        }
+    }
 }
 
 configurations.all {