Fix JUnit 4 integration to support PowerMock (#7046)

Author: nikita-tkachenko-datadog

dd-java-agent/instrumentation/junit-4.10/src/main/java/datadog/trace/instrumentation/junit4/JUnit4Instrumentation.java

@@ -1,6 +1,7 @@
 package datadog.trace.instrumentation.junit4;
 
 import static datadog.trace.agent.tooling.bytebuddy.matcher.HierarchyMatchers.extendsClass;
+import static datadog.trace.agent.tooling.bytebuddy.matcher.HierarchyMatchers.implementsInterface;
 import static datadog.trace.agent.tooling.bytebuddy.matcher.NameMatchers.named;
 import static net.bytebuddy.matcher.ElementMatchers.not;
 import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
@@ -50,7 +51,14 @@ public ElementMatcher<TypeDescription> hierarchyMatcher() {
         .and(not(extendsClass(named("datadog.trace.agent.test.SpockRunner"))))
         // do not instrument Karate JUnit 4 runner
         // since Karate has a dedicated instrumentation
-        .and(not(extendsClass(named("com.intuit.karate.junit4.Karate"))));
+        .and(not(extendsClass(named("com.intuit.karate.junit4.Karate"))))
+        // PowerMock runner is being instrumented,
+        // so do not instrument its internal delegates
+        .and(
+            not(
+                implementsInterface(
+                    named(
+                        "org.powermock.modules.junit4.common.internal.PowerMockJUnitRunnerDelegate"))));
   }
 
   @Override

dd-java-agent/instrumentation/junit-4.10/src/main/java/datadog/trace/instrumentation/junit4/JUnit4Utils.java

@@ -310,7 +310,8 @@ public static TestDescriptor toTestDescriptor(Description description) {
   public static TestSuiteDescriptor toSuiteDescriptor(Description description) {
     Class<?> testClass = description.getTestClass();
     String testSuiteName = JUnit4Utils.getSuiteName(testClass, description);
-    return new TestSuiteDescriptor(testSuiteName, testClass);
+    // relying exclusively on class name: some runners (such as PowerMock) may redefine test classes
+    return new TestSuiteDescriptor(testSuiteName, null);
   }
 
   /**

dd-java-agent/instrumentation/junit-4.10/src/main/java/datadog/trace/instrumentation/junit4/JUnit38SuiteEventsInstrumentation.java renamed to dd-java-agent/instrumentation/junit-4.10/src/main/java/datadog/trace/instrumentation/junit4/JUnitLegacySuiteEventsInstrumentation.java

@@ -14,18 +14,24 @@
 import org.junit.runner.notification.RunListener;
 import org.junit.runner.notification.RunNotifier;
 
-/** Supports suite started/finished events for {@link TestCase} subclasses. */
+/**
+ * Supports suite started/finished events for {@link TestCase} subclasses and Powermock-enabled test
+ * suites.
+ */
 @AutoService(InstrumenterModule.class)
-public class JUnit38SuiteEventsInstrumentation extends InstrumenterModule.CiVisibility
-    implements Instrumenter.ForSingleType {
+public class JUnitLegacySuiteEventsInstrumentation extends InstrumenterModule.CiVisibility
+    implements Instrumenter.ForKnownTypes {
 
-  public JUnit38SuiteEventsInstrumentation() {
-    super("ci-visibility", "junit-4", "junit-38");
+  public JUnitLegacySuiteEventsInstrumentation() {
+    super("ci-visibility", "junit-4", "junit-38", "powermock");
   }
 
   @Override
-  public String instrumentedType() {
-    return "org.junit.internal.runners.JUnit38ClassRunner";
+  public String[] knownMatchingTypes() {
+    return new String[] {
+      "org.junit.internal.runners.JUnit38ClassRunner",
+      "org.powermock.modules.junit4.PowerMockRunner"
+    };
   }
 
   @Override
@@ -50,10 +56,10 @@ public int order() {
   public void methodAdvice(MethodTransformer transformer) {
     transformer.applyAdvice(
         named("run").and(takesArgument(0, named("org.junit.runner.notification.RunNotifier"))),
-        JUnit38SuiteEventsInstrumentation.class.getName() + "$JUnit38SuiteEventsAdvice");
+        JUnitLegacySuiteEventsInstrumentation.class.getName() + "$JUnitLegacySuiteEventsAdvice");
   }
 
-  public static class JUnit38SuiteEventsAdvice {
+  public static class JUnitLegacySuiteEventsAdvice {
     @Advice.OnMethodEnter(suppress = Throwable.class)
     public static void fireSuiteStartedEvent(
         @Advice.Argument(0) final RunNotifier runNotifier, @Advice.This final Runner runner) {