testing-proto: add test for @RpcMethod

testing-proto/build.gradle

@@ -14,6 +14,7 @@ dependencies {
             project(':grpc-stub')
     compileOnly libraries.javax_annotation
     testCompile libraries.truth
+    testRuntime libraries.javax_annotation
 }
 
 configureProtoCompilation()

testing-proto/src/test/java/io/grpc/testing/protobuf/SimpleServiceTest.java

@@ -24,6 +24,23 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
 import io.grpc.MethodDescriptor;
+import io.grpc.stub.annotations.RpcMethod;
+import java.io.File;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.MirroredTypeException;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaCompiler.CompilationTask;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+import org.junit.Assume;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -57,4 +74,91 @@ public class SimpleServiceTest {
   public void generatedMethodsAreSampledToLocalTracing() throws Exception {
     assertTrue(SimpleServiceGrpc.getUnaryRpcMethod().isSampledToLocalTracing());
   }
+
+  public static class AnnotationProcessor extends AbstractProcessor {
+
+    private boolean processedClass = false;
+
+    @Override
+    public Set<String> getSupportedAnnotationTypes() {
+      return Collections.singleton(RpcMethod.class.getCanonicalName());
+    }
+
+    private void verifyRpcMethodAnnotation(
+        MethodDescriptor<SimpleRequest, SimpleResponse> descriptor, RpcMethod annotation) {
+      assertEquals(descriptor.getFullMethodName(), annotation.fullMethodName());
+      assertEquals(descriptor.getType(), annotation.methodType());
+
+      // Class objects may not be available at runtime, handle MirroredTypeException if it occurs
+      try {
+        assertEquals(SimpleRequest.class, annotation.requestType());
+      } catch (MirroredTypeException e) {
+        assertEquals(SimpleRequest.class.getCanonicalName(), e.getTypeMirror().toString());
+      }
+
+      try {
+        assertEquals(SimpleResponse.class, annotation.responseType());
+      } catch (MirroredTypeException e) {
+        assertEquals(SimpleResponse.class.getCanonicalName(), e.getTypeMirror().toString());
+      }
+    }
+
+    @Override
+    public synchronized boolean process(
+        Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+      for (Element rootElement : roundEnv.getRootElements()) {
+        if (!rootElement.asType().toString().equals(SimpleServiceGrpc.class.getCanonicalName())) {
+          continue;
+        }
+
+        Map<String, RpcMethod> methodToAnnotation = new HashMap<String, RpcMethod>();
+        for (Element enclosedElement : rootElement.getEnclosedElements()) {
+          RpcMethod annotation = enclosedElement.getAnnotation(RpcMethod.class);
+          if (annotation != null) {
+            methodToAnnotation.put(enclosedElement.getSimpleName().toString(), annotation);
+          }
+        }
+
+        verifyRpcMethodAnnotation(
+            SimpleServiceGrpc.getUnaryRpcMethod(), methodToAnnotation.get("getUnaryRpcMethod"));
+        verifyRpcMethodAnnotation(
+            SimpleServiceGrpc.getServerStreamingRpcMethod(),
+            methodToAnnotation.get("getServerStreamingRpcMethod"));
+        verifyRpcMethodAnnotation(
+            SimpleServiceGrpc.getClientStreamingRpcMethod(),
+            methodToAnnotation.get("getClientStreamingRpcMethod"));
+        verifyRpcMethodAnnotation(
+            SimpleServiceGrpc.getBidiStreamingRpcMethod(),
+            methodToAnnotation.get("getBidiStreamingRpcMethod"));
+
+        processedClass = true;
+      }
+      return false;
+    }
+  }
+
+  @Test
+  public void testRpcMethodAnnotations() throws Exception {
+    File grpcJavaFile =
+        new File("./src/generated/main/grpc/io/grpc/testing/protobuf/SimpleServiceGrpc.java");
+    Assume.assumeTrue(grpcJavaFile.exists());
+
+    JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+    StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
+    AnnotationProcessor processor = new AnnotationProcessor();
+    Iterable<? extends JavaFileObject> obs = fileManager.getJavaFileObjects(grpcJavaFile);
+
+    CompilationTask task =
+        compiler.getTask(
+            null,
+            fileManager,
+            null,
+            Collections.singleton("-proc:only"),
+            Collections.singleton(SimpleServiceGrpc.class.getCanonicalName()),
+            obs);
+    task.setProcessors(Collections.singleton(processor));
+    assertTrue(task.call());
+    assertTrue(processor.processedClass);
+    fileManager.close();
+  }
 }