Enable coverage when testJvm same as Gradle Daemon JDK or with checkCoverage property

buildSrc/src/main/kotlin/datadog/gradle/plugin/testJvmConstraints/TestJvmConstraintsPlugin.kt

@@ -45,12 +45,10 @@ class TestJvmConstraintsPlugin : Plugin<Project> {
     // Jacoco plugin is not applied on every project
     project.pluginManager.withPlugin("org.gradle.jacoco") {
       project.tasks.withType<Test>().configureEach {
-        // Disable jacoco for additional 'testJvm' tests to speed things up a bit
-        if (testJvmSpec.javaTestLauncher.isPresent) {
-          extensions.configure<JacocoTaskExtension> {
-            isEnabled = false
-          }
-        }
+        configureJacocoForAdditionalTestJvm(
+          testJvmSpec.javaTestLauncher.isPresent,
+          project.rootProject.providers.gradleProperty("checkCoverage").isPresent
+        )
       }
     }
   }
@@ -153,3 +151,15 @@ class TestJvmConstraintsPlugin : Plugin<Project> {
     taskExtension.nativeImageCapable.convention(projectExtension.nativeImageCapable)
   }
 }
+
+internal fun Test.configureJacocoForAdditionalTestJvm(
+  hasAdditionalTestJvmLauncher: Boolean,
+  checkCoverage: Boolean
+) {
+  // Disable jacoco for additional 'testJvm' tests unless coverage was explicitly requested.
+  if (hasAdditionalTestJvmLauncher && !checkCoverage) {
+    extensions.configure<JacocoTaskExtension> {
+      isEnabled = false
+    }
+  }
+}

buildSrc/src/test/kotlin/datadog/gradle/plugin/testJvmConstraints/TestJvmConstraintsPluginTest.kt

@@ -4,6 +4,7 @@ import datadog.gradle.plugin.testJvmConstraints.TestJvmConstraintsExtension.Comp
 import org.assertj.core.api.Assertions.assertThat
 import org.gradle.api.tasks.testing.Test as GradleTest
 import org.gradle.testfixtures.ProjectBuilder
+import org.gradle.testing.jacoco.plugins.JacocoTaskExtension
 import org.junit.jupiter.api.Test
 
 class TestJvmConstraintsPluginTest {
@@ -19,4 +20,52 @@ class TestJvmConstraintsPluginTest {
     assertThat(project.extensions.findByName(TEST_JVM_CONSTRAINTS)).isInstanceOf(TestJvmConstraintsExtension::class.java)
     assertThat(testTask.extensions.findByName(TEST_JVM_CONSTRAINTS)).isInstanceOf(TestJvmConstraintsExtension::class.java)
   }
+
+  @Test
+  fun `jacoco is disabled for additional test jvm when coverage is not checked`() {
+    val testTask = testTaskWithJacoco()
+
+    testTask.configureJacocoForAdditionalTestJvm(
+      hasAdditionalTestJvmLauncher = true,
+      checkCoverage = false
+    )
+
+    assertThat(jacocoExtension(testTask).isEnabled).isFalse()
+  }
+
+  @Test
+  fun `jacoco remains enabled for additional test jvm when coverage is checked`() {
+    val testTask = testTaskWithJacoco()
+
+    testTask.configureJacocoForAdditionalTestJvm(
+      hasAdditionalTestJvmLauncher = true,
+      checkCoverage = true
+    )
+
+    assertThat(jacocoExtension(testTask).isEnabled).isTrue()
+  }
+
+  @Test
+  fun `jacoco remains enabled when using the daemon jvm`() {
+    val testTask = testTaskWithJacoco()
+
+    testTask.configureJacocoForAdditionalTestJvm(
+      hasAdditionalTestJvmLauncher = false,
+      checkCoverage = false
+    )
+
+    assertThat(jacocoExtension(testTask).isEnabled).isTrue()
+  }
+
+  private fun testTaskWithJacoco(): GradleTest {
+    val project = ProjectBuilder.builder().build()
+
+    project.pluginManager.apply("java")
+    project.pluginManager.apply("jacoco")
+
+    return project.tasks.named("test", GradleTest::class.java).get()
+  }
+
+  private fun jacocoExtension(testTask: GradleTest): JacocoTaskExtension =
+    testTask.extensions.getByType(JacocoTaskExtension::class.java)
 }