Allow forked test tasks for source sets other than test

gradle/java_no_deps.gradle

@@ -150,13 +150,8 @@ ext.testcontainersLimit = gradle.sharedServices.registerIfAbsent("testcontainers
   maxParallelUsages = project.findProperty("testcontainersMaxParallelUsages").toInteger()
 }
 
-// Task for tests that want to run forked in their own separate JVM
-tasks.register('forkedTest', Test) {
-  group = LifecycleBasePlugin.VERIFICATION_GROUP
-  useJUnitPlatform()
-  testClassesDirs = sourceSets.test.output.classesDirs
-  classpath = sourceSets.test.runtimeClasspath
-}
+// Every project gets a forked test task for its default 'test' source set.
+addForkedTestTask('test')
 
 // testRuntimeActivation is registered in individual module build files after this convention is
 // applied, so tasks.named() won't work here — use a lazy hook that intercepts it on registration.

gradle/test-suites.gradle

@@ -77,3 +77,29 @@ ext.addTestSuiteForDir = { testSuiteName, dirName ->
 ext.addTestSuite = { testSuiteName ->
   ext.addTestSuiteForDir(testSuiteName, testSuiteName)
 }
+
+// Registers a task that runs the '*ForkedTest' classes of a source set, each in its own JVM.
+//
+// The task name ends in 'ForkedTest', which is what makes the test convention plugin restrict it to
+// '**/*ForkedTest*', set forkEvery=1 and apply the shared forked-test concurrency limit. 'check',
+// 'allTests' and 'allLatestDepTests' pick the task up automatically, because they match Test tasks
+// by type rather than by name.
+//
+// Modules whose tests live in the default 'test' source set get 'forkedTest' registered for them by
+// java_no_deps.gradle. Modules that use their own suites instead - for example to compile the same
+// tests against several Scala versions - have no 'test' sources, so their forked tests never run
+// unless they opt in:
+//
+//   addTestSuite('baseTest')
+//   addForkedTestTask('baseTest')  // registers 'baseTestForkedTest'
+//
+// Returns the TaskProvider so callers can configure the task further.
+ext.addForkedTestTask = { String sourceSetName ->
+  def taskName = sourceSetName == 'test' ? 'forkedTest' : "${sourceSetName}ForkedTest"
+  return tasks.register(taskName, Test) {
+    group = LifecycleBasePlugin.VERIFICATION_GROUP
+    useJUnitPlatform()
+    testClassesDirs = sourceSets[sourceSetName].output.classesDirs
+    classpath = sourceSets[sourceSetName].runtimeClasspath
+  }
+}