Fix tests using precompiled MyResource class

dd-java-agent/agent-debugger/build.gradle

@@ -77,6 +77,8 @@ dependencies {
   testImplementation project(':dd-java-agent:agent-debugger:debugger-test-scala')
   testImplementation project(':dd-trace-core')
   testImplementation project(':dd-java-agent:agent-installer')
+  testImplementation project(':dd-java-agent:instrumentation:rs:jax-rs:jax-rs-annotations:jax-rs-annotations-2.0')
+  testImplementation group: 'javax.ws.rs', name: 'javax.ws.rs-api', version: '2.1.1'
   testImplementation project(':remote-config:remote-config-core')
   testImplementation project(':utils:test-utils')
 

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/CapturedSnapshotTest.java

@@ -27,6 +27,7 @@
 import static utils.InstrumentationTestHelper.compile;
 import static utils.InstrumentationTestHelper.compileAndLoadClass;
 import static utils.InstrumentationTestHelper.getLineForLineProbe;
+import static utils.InstrumentationTestHelper.installTracerInstrumentation;
 import static utils.InstrumentationTestHelper.loadClass;
 import static utils.TestClassFileHelper.getClassFileBytes;
 import static utils.TestHelper.getFixtureContent;
@@ -72,6 +73,7 @@
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.lang.instrument.ClassFileTransformer;
 import java.lang.instrument.Instrumentation;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -1838,26 +1840,33 @@ public void multiLambdas() throws IOException, URISyntaxException {
   public void tracerInstrumentedClass() throws Exception {
     DebuggerContext.initClassFilter(new DenyListHelper(null));
     final String CLASS_NAME = "com.datadog.debugger.jaxrs.MyResource";
-    TestSnapshotListener listener = installMethodProbe(CLASS_NAME, "createResource", null);
-    // load a class file that was previously instrumented by the DD tracer as JAX-RS resource
-    Class<?> testClass =
-        loadClass(CLASS_NAME, getClass().getResource("/MyResource.class").getFile());
-    Object result =
-        Reflect.onClass(testClass)
-            .create()
-            .call("createResource", (Object) null, (Object) null, 1)
-            .get();
-    Snapshot snapshot = assertOneSnapshot(listener);
-    Map<String, CapturedContext.CapturedValue> arguments =
-        snapshot.getCaptures().getEntry().getArguments();
-    // it's important there is no null key in this map, as Jackson is not happy about it
-    // it's means here that argument names are not resolved correctly
-    Assertions.assertFalse(arguments.containsKey(null));
-    assertEquals(4, arguments.size());
-    assertTrue(arguments.containsKey("this"));
-    assertTrue(arguments.containsKey("apiKey"));
-    assertTrue(arguments.containsKey("uriInfo"));
-    assertTrue(arguments.containsKey("value"));
+    // compile the JAX-RS resource fixture and weave it with the real tracer JAX-RS
+    // instrumentation, so this test exercises argument-name resolution against the same
+    // bytecode shape the tracer actually produces
+    ClassFileTransformer jaxRsTransformer = installTracerInstrumentation(instr);
+    Class<?> testClass;
+    try {
+      TestSnapshotListener listener = installMethodProbe(CLASS_NAME, "createResource", null);
+      testClass = compileAndLoadClass(CLASS_NAME);
+      Object result =
+          Reflect.onClass(testClass)
+              .create()
+              .call("createResource", (Object) null, (Object) null, 1)
+              .get();
+      Snapshot snapshot = assertOneSnapshot(listener);
+      Map<String, CapturedContext.CapturedValue> arguments =
+          snapshot.getCaptures().getEntry().getArguments();
+      // it's important there is no null key in this map, as Jackson is not happy about it
+      // it's means here that argument names are not resolved correctly
+      Assertions.assertFalse(arguments.containsKey(null));
+      assertEquals(4, arguments.size());
+      assertTrue(arguments.containsKey("this"));
+      assertTrue(arguments.containsKey("apiKey"));
+      assertTrue(arguments.containsKey("uriInfo"));
+      assertTrue(arguments.containsKey("value"));
+    } finally {
+      instr.removeTransformer(jaxRsTransformer);
+    }
   }
 
   @Test

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/MetricProbesInstrumentationTest.java

@@ -19,7 +19,7 @@
 import static org.mockito.Mockito.when;
 import static utils.InstrumentationTestHelper.compileAndLoadClass;
 import static utils.InstrumentationTestHelper.getLineForLineProbe;
-import static utils.InstrumentationTestHelper.loadClass;
+import static utils.InstrumentationTestHelper.installTracerInstrumentation;
 
 import com.datadog.debugger.el.DSL;
 import com.datadog.debugger.el.ValueScript;
@@ -1291,21 +1291,28 @@ public void primitivesFunction() throws IOException, URISyntaxException {
   public void localVarNotInScope() throws IOException, URISyntaxException {
     final String METRIC_NAME = "lenstr";
     final String CLASS_NAME = "com.datadog.debugger.jaxrs.MyResource";
-    MetricProbe metricProbe =
-        createMetricBuilder(METRIC_ID, METRIC_NAME, GAUGE)
-            .where(CLASS_NAME, "createResource", null)
-            .valueScript(new ValueScript(DSL.len(DSL.ref("varStr")), "len(varStr)"))
-            .build();
-    MetricForwarderListener listener = installMetricProbes(metricProbe);
-    Class<?> testClass =
-        loadClass(CLASS_NAME, getClass().getResource("/MyResource.class").getFile());
-    Object result =
-        Reflect.onClass(testClass)
-            .create()
-            .call("createResource", (Object) null, (Object) null, 1)
-            .get();
-    assertNotNull(result);
-    assertFalse(listener.gauges.containsKey(METRIC_NAME));
+    // compile the JAX-RS resource fixture and weave it with the real tracer JAX-RS
+    // instrumentation, so this test exercises the same bytecode shape the tracer produces
+    ClassFileTransformer jaxRsTransformer = installTracerInstrumentation(instr);
+    Class<?> testClass;
+    try {
+      MetricProbe metricProbe =
+          createMetricBuilder(METRIC_ID, METRIC_NAME, GAUGE)
+              .where(CLASS_NAME, "createResource", null)
+              .valueScript(new ValueScript(DSL.len(DSL.ref("varStr")), "len(varStr)"))
+              .build();
+      MetricForwarderListener listener = installMetricProbes(metricProbe);
+      testClass = compileAndLoadClass(CLASS_NAME);
+      Object result =
+          Reflect.onClass(testClass)
+              .create()
+              .call("createResource", (Object) null, (Object) null, 1)
+              .get();
+      assertNotNull(result);
+      assertFalse(listener.gauges.containsKey(METRIC_NAME));
+    } finally {
+      instr.removeTransformer(jaxRsTransformer);
+    }
   }
 
   private MetricForwarderListener installMethodMetric(

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/SnapshotSerializationTest.java

@@ -179,6 +179,12 @@ public void roundTripCaughtException() throws IOException {
                 new CapturedStackFrame("f2", 23),
                 new CapturedStackFrame("f3", 34)),
             null));
+    captures.addCaughtException(
+        new CapturedContext.CapturedThrowable(
+            NullPointerException.class.getTypeName(),
+            "illegal argument",
+            Collections.emptyList(),
+            null));
     String buffer = adapter.toJson(snapshot);
     System.out.println("roundTripCaughtException: " + buffer);
     Snapshot deserializedSnapshot = adapter.fromJson(buffer);

dd-java-agent/agent-debugger/src/test/java/utils/InstrumentationTestHelper.java

@@ -4,15 +4,21 @@
 import static utils.TestHelper.getFixtureLines;
 
 import com.datadog.debugger.agent.CapturedSnapshotTest;
+import datadog.instrument.classinject.ClassInjector;
+import datadog.trace.agent.tooling.AgentInstaller;
+import datadog.trace.agent.tooling.InstrumenterModule;
 import datadog.trace.bootstrap.debugger.ProbeId;
 import java.io.IOException;
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.Instrumentation;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Collections;
+import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -84,6 +90,19 @@ public static int getLineForLineProbe(String className, ProbeId lineProbeId) {
     return getLineForLineProbe(className, ".java", lineProbeId);
   }
 
+  /**
+   * Installs the real tracer instrumentation modules (e.g. jax-rs-annotations) on top of the given
+   * {@link Instrumentation}, so that classes defined afterwards (typically via {@link
+   * #compileAndLoadClass}) are woven with actual tracer advice, the same way they would be by the
+   * production agent. Callers must remove the returned transformer once done, e.g. via {@link
+   * Instrumentation#removeTransformer(ClassFileTransformer)}.
+   */
+  public static ClassFileTransformer installTracerInstrumentation(Instrumentation instr) {
+    ClassInjector.enableClassInjection(instr);
+    return AgentInstaller.installBytebuddyAgent(
+        instr, false, EnumSet.of(InstrumenterModule.TargetSystem.TRACING));
+  }
+
   public static int getLineForLineProbe(String className, String ext, ProbeId lineProbeId) {
     List<String> lines = getFixtureLines("/" + className.replace('.', '/') + ext);
     for (int i = 0; i < lines.size(); i++) {

dd-java-agent/agent-debugger/src/test/resources/com/datadog/debugger/jaxrs/MyResource.java

@@ -0,0 +1,18 @@
+package com.datadog.debugger.jaxrs;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.Context;
+
+@Path("myresource")
+public class MyResource {
+
+  @GET
+  public Object createResource(
+      String apiKey, @Context String uriInfo, @QueryParam("value") int value) {
+    String varStr = "foo";
+    Object response = new Object();
+    return response;
+  }
+}