[samplecode][2/3]Implement Stream.Bidi sample code

src/main/java/com/google/api/generator/gapic/composer/ServiceClientClassComposer.java

@@ -806,7 +806,7 @@ private static MethodDefinition createCallableMethod(
     }
     // TODO (summerji): Implement sample code for stream method.
     // Replace by if (method.stream()).
-    if (method.stream().equals(Stream.SERVER)) {
+    if (method.stream().equals(Stream.SERVER) || method.stream().equals(Stream.BIDI)) {
       sampleCodeOpt =
           Optional.of(
               ServiceClientSampleCodeComposer.composeStreamCallableMethodHeaderSampleCode(

src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposer.java

@@ -17,6 +17,7 @@
 import com.google.api.core.ApiFuture;
 import com.google.api.gax.core.FixedCredentialsProvider;
 import com.google.api.gax.longrunning.OperationFuture;
+import com.google.api.gax.rpc.BidiStream;
 import com.google.api.gax.rpc.ServerStream;
 import com.google.api.generator.engine.ast.AssignmentExpr;
 import com.google.api.generator.engine.ast.CommentStatement;
@@ -36,6 +37,7 @@
 import com.google.api.generator.gapic.model.Field;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.Method.Stream;
 import com.google.api.generator.gapic.model.MethodArgument;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.utils.JavaStyle;
@@ -552,8 +554,15 @@ public static String composeStreamCallableMethodHeaderSampleCode(
             .build();
 
     // TODO (summerji) : Implement Stream.Client and Stream.Bidi sample code body statements.
-    List<Statement> bodyStatements =
-        composeStreamServerSampleCodeBodyStatements(method, clientVarExpr, requestAssignmentExpr);
+    List<Statement> bodyStatements = new ArrayList<>();
+    if (method.stream().equals(Stream.SERVER)) {
+      bodyStatements.addAll(
+          composeStreamServerSampleCodeBodyStatements(
+              method, clientVarExpr, requestAssignmentExpr));
+    } else if (method.stream().equals(Stream.BIDI)) {
+      bodyStatements.addAll(
+          composeStreamBidiSampleCodeBodyStatements(method, clientVarExpr, requestAssignmentExpr));
+    }
 
     return SampleCodeWriter.write(
         TryCatchStatement.builder()
@@ -761,6 +770,79 @@ private static List<Statement> composeStreamServerSampleCodeBodyStatements(
     return bodyStatements;
   }
 
+  private static List<Statement> composeStreamBidiSampleCodeBodyStatements(
+      Method method, VariableExpr clientVarExpr, AssignmentExpr requestAssignmentExpr) {
+    List<Expr> bodyExprs = new ArrayList<>();
+
+    // Create bidi stream variable expression and assign it with invoking client's bidi stream
+    // method.
+    // e.g. BidiStream<EchoRequest, EchoResponse> bidiStream = echoClient.chatCallable().call();
+    TypeNode bidiStreamType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(BidiStream.class)
+                .setGenerics(method.inputType().reference(), method.outputType().reference())
+                .build());
+    VariableExpr bidiStreamVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("bidiStream").setType(bidiStreamType).build());
+    MethodInvocationExpr clientBidiStreamCallMethodInvoationExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(clientVarExpr)
+            .setMethodName(JavaStyle.toLowerCamelCase(String.format("%sCallable", method.name())))
+            .build();
+    clientBidiStreamCallMethodInvoationExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(clientBidiStreamCallMethodInvoationExpr)
+            .setMethodName("call")
+            .setReturnType(bidiStreamType)
+            .build();
+    AssignmentExpr bidiStreamAssignmentExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(bidiStreamVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(clientBidiStreamCallMethodInvoationExpr)
+            .build();
+    bodyExprs.add(bidiStreamAssignmentExpr);
+
+    // Add request with default value expression.
+    bodyExprs.add(requestAssignmentExpr);
+
+    // Invoke send method with argument request.
+    // e.g. bidiStream.send(request);
+    MethodInvocationExpr sendMethodInvocationExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(bidiStreamVarExpr)
+            .setArguments(requestAssignmentExpr.variableExpr().toBuilder().setIsDecl(false).build())
+            .setMethodName("send")
+            .build();
+    bodyExprs.add(sendMethodInvocationExpr);
+
+    List<Statement> bodyStatements =
+        bodyExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList());
+
+    // For-loop on bidi stream variable.
+    // e.g. for (EchoResponse response : bidiStream) {
+    //        // Do something when reveive a response.
+    //      }
+    ForStatement forStatement =
+        ForStatement.builder()
+            .setLocalVariableExpr(
+                VariableExpr.builder()
+                    .setVariable(
+                        Variable.builder().setType(method.outputType()).setName("response").build())
+                    .setIsDecl(true)
+                    .build())
+            .setCollectionExpr(bidiStreamVarExpr)
+            .setBody(
+                Arrays.asList(
+                    CommentStatement.withComment(
+                        LineComment.withComment("Do something when a response is received."))))
+            .build();
+    bodyStatements.add(forStatement);
+
+    return bodyStatements;
+  }
+
   // ==================================Helpers===================================================//
 
   // Create a list of RPC method arguments' variable expressions.

src/test/java/com/google/api/generator/gapic/composer/goldens/EchoClient.golden

@@ -353,13 +353,49 @@ public class EchoClient implements BackgroundResource {
   }
 
   // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /** Sample code: */
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (EchoClient echoClient = EchoClient.create()) {
+   *   BidiStream<EchoRequest, EchoResponse> bidiStream = echoClient.chatCallable().call();
+   *   EchoRequest request =
+   *       EchoRequest.newBuilder()
+   *           .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setFoobar(Foobar.newBuilder().build())
+   *           .build();
+   *   bidiStream.send(request);
+   *   for (EchoResponse response : bidiStream) {
+   *     // Do something when a response is received.
+   *   }
+   * }
+   * }</pre>
+   */
   public final BidiStreamingCallable<EchoRequest, EchoResponse> chatCallable() {
     return stub.chatCallable();
   }
 
   // AUTO-GENERATED DOCUMENTATION AND METHOD.
-  /** Sample code: */
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (EchoClient echoClient = EchoClient.create()) {
+   *   BidiStream<EchoRequest, EchoResponse> bidiStream = echoClient.chatAgainCallable().call();
+   *   EchoRequest request =
+   *       EchoRequest.newBuilder()
+   *           .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setFoobar(Foobar.newBuilder().build())
+   *           .build();
+   *   bidiStream.send(request);
+   *   for (EchoResponse response : bidiStream) {
+   *     // Do something when a response is received.
+   *   }
+   * }
+   * }</pre>
+   */
   public final BidiStreamingCallable<EchoRequest, EchoResponse> chatAgainCallable() {
     return stub.chatAgainCallable();
   }

src/test/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposerTest.java

@@ -1767,5 +1767,93 @@ public void invalidComposeStreamCallableMethodHeaderSampleCode_serverStreamNotEx
             ServiceClientSampleCodeComposer.composeStreamCallableMethodHeaderSampleCode(
                 method, clientType, resourceNames, messageTypes));
   }
+
+  @Test
+  public void validComposeStreamCallableMethodHeaderSampleCode_bidiStream() {
+    FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
+    Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
+    Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
+    TypeNode clientType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoClient")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    TypeNode inputType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoRequest")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    TypeNode outputType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoResponse")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    Method method =
+        Method.builder()
+            .setName("chat")
+            .setInputType(inputType)
+            .setOutputType(outputType)
+            .setStream(Stream.BIDI)
+            .build();
+    String results =
+        ServiceClientSampleCodeComposer.composeStreamCallableMethodHeaderSampleCode(
+            method, clientType, resourceNames, messageTypes);
+    String expected =
+        LineFormatter.lines(
+            "try (EchoClient echoClient = EchoClient.create()) {\n",
+            "  BidiStream<EchoRequest, EchoResponse> bidiStream = echoClient.chatCallable().call();\n",
+            "  EchoRequest request =\n",
+            "      EchoRequest.newBuilder()\n",
+            "          .setName(FoobarName.ofProjectFoobarName(\"[PROJECT]\", \"[FOOBAR]\").toString())\n",
+            "          .setParent(FoobarName.ofProjectFoobarName(\"[PROJECT]\", \"[FOOBAR]\").toString())\n",
+            "          .setFoobar(Foobar.newBuilder().build())\n",
+            "          .build();\n",
+            "  bidiStream.send(request);\n",
+            "  for (EchoResponse response : bidiStream) {\n",
+            "    // Do something when a response is received.\n",
+            "  }\n",
+            "}");
+    assertEquals(results, expected);
+  }
+
+  @Test
+  public void invalidComposeStreamCallableMethodHeaderSampleCode_bidiStreamNotExistRequest() {
+    FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
+    Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
+    Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
+    TypeNode clientType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoClient")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    TypeNode inputType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("NotExistRequest")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    TypeNode outputType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoResponse")
+                .setPakkage(SHOWCASE_PACKAGE_NAME)
+                .build());
+    Method method =
+        Method.builder()
+            .setName("chat")
+            .setInputType(inputType)
+            .setOutputType(outputType)
+            .setStream(Stream.BIDI)
+            .build();
+    assertThrows(
+        NullPointerException.class,
+        () ->
+            ServiceClientSampleCodeComposer.composeStreamCallableMethodHeaderSampleCode(
+                method, clientType, resourceNames, messageTypes));
+  }
 }