add tracing for junit4 setup/teardown actions

Author: daniel-mohedano

dd-java-agent/instrumentation/junit-4.10/src/main/java/datadog/trace/instrumentation/junit4/JUnit4BeforeAfterInstrumentation.java

@@ -0,0 +1,67 @@
+package datadog.trace.instrumentation.junit4;
+
+import static datadog.trace.agent.tooling.bytebuddy.matcher.NameMatchers.named;
+import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
+
+import com.google.auto.service.AutoService;
+import datadog.trace.agent.tooling.Instrumenter;
+import datadog.trace.agent.tooling.InstrumenterModule;
+import datadog.trace.bootstrap.instrumentation.api.AgentScope;
+import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
+import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
+import datadog.trace.bootstrap.instrumentation.api.Tags;
+import net.bytebuddy.asm.Advice;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.runners.model.FrameworkMethod;
+
+@AutoService(InstrumenterModule.class)
+public class JUnit4BeforeAfterInstrumentation extends InstrumenterModule.CiVisibility
+    implements Instrumenter.ForKnownTypes {
+
+  public JUnit4BeforeAfterInstrumentation() {
+    super("ci-visibility", "junit-4", "setup-teardown");
+  }
+
+  @Override
+  public String[] knownMatchingTypes() {
+    return new String[] {
+      "org.junit.internal.runners.statements.RunBefores",
+      "org.junit.internal.runners.statements.RunAfters"
+    };
+  }
+
+  @Override
+  public void methodAdvice(MethodTransformer transformer) {
+    transformer.applyAdvice(
+        named("invokeMethod")
+            .and(takesArgument(0, named("org.junit.runners.model.FrameworkMethod"))),
+        JUnit4BeforeAfterInstrumentation.class.getName() + "$RunBeforesAftersAdvice");
+  }
+
+  public static class RunBeforesAftersAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static AgentScope startCallSpan(@Advice.Argument(0) final FrameworkMethod method) {
+      final AgentSpan span = AgentTracer.startSpan("junit", method.getMethod().getName());
+      if (method.getMethod().isAnnotationPresent(Before.class)) {
+        span.setTag(Tags.TEST_CALLBACK, "Before");
+      } else if (method.getMethod().isAnnotationPresent(After.class)) {
+        span.setTag(Tags.TEST_CALLBACK, "After");
+      } else if (method.getMethod().isAnnotationPresent(BeforeClass.class)) {
+        span.setTag(Tags.TEST_CALLBACK, "BeforeClass");
+      } else if (method.getMethod().isAnnotationPresent(AfterClass.class)) {
+        span.setTag(Tags.TEST_CALLBACK, "AfterClass");
+      }
+      return AgentTracer.activateSpan(span);
+    }
+
+    @Advice.OnMethodExit(suppress = Throwable.class)
+    public static void finishCallSpan(@Advice.Enter final AgentScope scope) {
+      AgentSpan span = scope.span();
+      scope.close();
+      span.finish();
+    }
+  }
+}