feat: Do not generate Service REST code if there are no matching RPC in a Service

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceCallableFactoryClassComposer.java

@@ -62,6 +62,11 @@ protected TransportContext getTransportContext() {
 
   @Override
   public GapicClass generate(GapicContext context, Service service) {
+    // Do not generate the Callable Factory if there are no RPCs enabled for the Transport
+    if (!service.hasAnyEnabledMethodsForTransport(getTransportContext().transport())) {
+      return GapicClass.createNonGeneratedGapicClass();
+    }
+
     TypeStore typeStore = createTypes(service);
 
     String className =

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientTestClassComposer.java

@@ -109,6 +109,11 @@ public GapicClass generate(GapicContext context, Service service) {
   }
 
   protected GapicClass generate(String className, GapicContext context, Service service) {
+    // Do not generate Client Test code for Transport if there are no matching RPCs for a Transport
+    if (!service.hasAnyEnabledMethodsForTransport(getTransportContext().transport())) {
+      return GapicClass.createNonGeneratedGapicClass();
+    }
+
     Map<String, ResourceName> resourceNames = context.helperResourceNames();
     String pakkage = service.pakkage();
     TypeStore typeStore = new TypeStore();
@@ -131,10 +136,6 @@ protected GapicClass generate(String className, GapicContext context, Service se
     return GapicClass.create(kind, classDef);
   }
 
-  protected boolean isSupportedMethod(Method method) {
-    return true;
-  }
-
   private List<AnnotationNode> createClassAnnotations() {
     return Arrays.asList(
         AnnotationNode.builder()
@@ -230,7 +231,7 @@ private List<MethodDefinition> createTestMethods(
     Map<String, Message> messageTypes = context.messages();
     List<MethodDefinition> javaMethods = new ArrayList<>();
     for (Method method : service.methods()) {
-      if (!isSupportedMethod(method)) {
+      if (!method.isSupportedByTransport(getTransportContext().transport())) {
         javaMethods.add(createUnsupportedTestMethod(method));
         continue;
       }

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceSettingsClassComposer.java

@@ -385,6 +385,14 @@ private List<MethodDefinition> createDefaultGetterMethods(Service service, TypeS
     while (providerBuilderNamesIt.hasNext()
         && channelProviderClassesIt.hasNext()
         && transportNamesIt.hasNext()) {
+      String providerBuilderName = providerBuilderNamesIt.next();
+      Class<?> channelProviderClass = channelProviderClassesIt.next();
+      String transportName = transportNamesIt.next();
+
+      if (!service.hasAnyEnabledMethodsForTransport(transportName)) {
+        continue;
+      }
+
       List<AnnotationNode> annotations = ImmutableList.of();
 
       // For clients supporting multiple transports (mainly grpc+rest case) make secondary transport
@@ -397,16 +405,13 @@ private List<MethodDefinition> createDefaultGetterMethods(Service service, TypeS
           SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT;
       if (getTransportContext().transportNames().size() > 1) {
         commentStatement =
-            new SettingsCommentComposer(transportNamesIt.next())
-                .getTransportProviderBuilderMethodComment();
+            new SettingsCommentComposer(transportName).getTransportProviderBuilderMethodComment();
       }
 
       javaMethods.add(
           methodMakerFn.apply(
               methodStarterFn
-                  .apply(
-                      providerBuilderNamesIt.next(),
-                      typeMakerFn.apply(channelProviderClassesIt.next()))
+                  .apply(providerBuilderName, typeMakerFn.apply(channelProviderClass))
                   .setAnnotations(annotations),
               commentStatement));
       secondaryTransportProviderBuilder = true;

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java

@@ -243,7 +243,8 @@ protected MethodDefinition createDefaultCredentialsProviderBuilderMethod() {
         .build();
   }
 
-  protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderMethods() {
+  protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderMethods(
+      Service service) {
     // Create the defaultGrpcTransportProviderBuilder method.
     Iterator<Class<?>> providerClassIt =
         getTransportContext().instantiatingChannelProviderClasses().iterator();
@@ -259,10 +260,19 @@ protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderM
         && providerBuilderClassIt.hasNext()
         && builderNamesIt.hasNext()
         && transportNamesIt.hasNext()) {
+      Class<?> providerClass = providerClassIt.next();
+      Class<?> providerBuilderClass = providerBuilderClassIt.next();
+      String builderName = builderNamesIt.next();
+      String transportName = transportNamesIt.next();
+
+      if (!service.hasAnyEnabledMethodsForTransport(transportName)) {
+        continue;
+      }
+
       TypeNode returnType =
-          TypeNode.withReference(ConcreteReference.withClazz(providerBuilderClassIt.next()));
+          TypeNode.withReference(ConcreteReference.withClazz(providerBuilderClass));
       TypeNode channelProviderType =
-          TypeNode.withReference(ConcreteReference.withClazz(providerClassIt.next()));
+          TypeNode.withReference(ConcreteReference.withClazz(providerClass));
 
       MethodInvocationExpr transportChannelProviderBuilderExpr =
           MethodInvocationExpr.builder()
@@ -281,8 +291,7 @@ protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderM
           SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT;
       if (getTransportContext().transportNames().size() > 1) {
         commentStatement =
-            new SettingsCommentComposer(transportNamesIt.next())
-                .getTransportProviderBuilderMethodComment();
+            new SettingsCommentComposer(transportName).getTransportProviderBuilderMethodComment();
       }
 
       MethodDefinition method =
@@ -292,7 +301,7 @@ protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderM
               .setScope(ScopeNode.PUBLIC)
               .setIsStatic(true)
               .setReturnType(returnType)
-              .setName(builderNamesIt.next())
+              .setName(builderName)
               .setReturnExpr(returnExpr)
               .build();
 
@@ -1047,17 +1056,23 @@ private MethodDefinition createCreateStubMethod(Service service, TypeStore typeS
             .setMethodName("getTransportName")
             .build();
 
+    Iterator<String> transportNamesIt = getTransportContext().transportNames().iterator();
     Iterator<TypeNode> channelTypesIt = getTransportContext().transportChannelTypes().iterator();
     Iterator<String> getterNameIt = getTransportContext().transportGetterNames().iterator();
     Iterator<String> serivceStubClassNameIt =
         getTransportContext().classNames().getTransportServiceStubClassNames(service).iterator();
 
     while (channelTypesIt.hasNext() && getterNameIt.hasNext()) {
+      String transportName = transportNamesIt.next();
       TypeNode channelType = channelTypesIt.next();
       String getterName = getterNameIt.next();
       String serivceStubClassName = serivceStubClassNameIt.next();
 
-      Expr tRansportNameExpr =
+      if (!service.hasAnyEnabledMethodsForTransport(transportName)) {
+        continue;
+      }
+
+      Expr transportNameExpr =
           MethodInvocationExpr.builder()
               .setStaticReferenceType(channelType)
               .setMethodName(getterName)
@@ -1067,7 +1082,7 @@ private MethodDefinition createCreateStubMethod(Service service, TypeStore typeS
           MethodInvocationExpr.builder()
               .setExprReferenceExpr(getTransportNameExpr)
               .setMethodName("equals")
-              .setArguments(tRansportNameExpr)
+              .setArguments(transportNameExpr)
               .setReturnType(TypeNode.BOOLEAN)
               .build();
 
@@ -1191,7 +1206,7 @@ private List<MethodDefinition> createDefaultHelperAndGetterMethods(
             .build());
 
     javaMethods.add(createDefaultCredentialsProviderBuilderMethod());
-    javaMethods.addAll(createDefaultTransportTransportProviderBuilderMethods());
+    javaMethods.addAll(createDefaultTransportTransportProviderBuilderMethods(service));
     javaMethods.add(createDefaultTransportChannelProviderMethod());
     javaMethods.addAll(createApiClientHeaderProviderBuilderMethods(service, typeStore));
 
@@ -1424,7 +1439,7 @@ private List<MethodDefinition> createNestedClassMethods(
     nestedClassMethods.addAll(
         createNestedClassConstructorMethods(
             service, serviceConfig, nestedMethodSettingsMemberVarExprs, typeStore));
-    nestedClassMethods.addAll(createNestedClassCreateDefaultMethods(typeStore));
+    nestedClassMethods.addAll(createNestedClassCreateDefaultMethods(service, typeStore));
     nestedClassMethods.add(createNestedClassInitDefaultsMethod(service, serviceConfig, typeStore));
     nestedClassMethods.add(createNestedClassApplyToAllUnaryMethodsMethod(superType, typeStore));
     nestedClassMethods.add(createNestedClassUnaryMethodSettingsBuilderGetterMethod());
@@ -1762,14 +1777,19 @@ private static List<MethodDefinition> createNestedClassConstructorMethods(
     return ctorMethods;
   }
 
-  protected List<MethodDefinition> createNestedClassCreateDefaultMethods(TypeStore typeStore) {
-    return Collections.singletonList(
-        createNestedClassCreateDefaultMethod(
-            typeStore,
-            "createDefault",
-            "defaultTransportChannelProvider",
-            null,
-            "defaultApiClientHeaderProviderBuilder"));
+  protected List<MethodDefinition> createNestedClassCreateDefaultMethods(
+      Service service, TypeStore typeStore) {
+    if (service.hasAnyEnabledMethodsForTransport(getTransportContext().transport())) {
+      return Arrays.asList(
+          createNestedClassCreateDefaultMethod(
+              typeStore,
+              "createDefault",
+              "defaultTransportChannelProvider",
+              null,
+              "defaultApiClientHeaderProviderBuilder"));
+    } else {
+      return Collections.emptyList();
+    }
   }
 
   protected MethodDefinition createNestedClassCreateDefaultMethod(

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractTransportServiceStubClassComposer.java

@@ -59,7 +59,6 @@
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.model.Service;
-import com.google.api.generator.gapic.model.Transport;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
@@ -94,7 +93,7 @@ public abstract class AbstractTransportServiceStubClassComposer implements Class
   private static final String OPERATION_CALLABLE_CLASS_MEMBER_PATTERN = "%sOperationCallable";
   private static final String OPERATION_CALLABLE_NAME = "OperationCallable";
   // private static final String OPERATIONS_STUB_MEMBER_NAME = "operationsStub";
-  private static final String PAGED_CALLABLE_NAME = "PagedCallable";
+  protected static final String PAGED_CALLABLE_NAME = "PagedCallable";
 
   protected static final TypeStore FIXED_TYPESTORE = createStaticTypes();
 
@@ -134,6 +133,10 @@ private static TypeStore createStaticTypes() {
 
   @Override
   public GapicClass generate(GapicContext context, Service service) {
+    if (!service.hasAnyEnabledMethodsForTransport(getTransportContext().transport())) {
+      return GapicClass.createNonGeneratedGapicClass();
+    }
+
     String pakkage = service.pakkage() + ".stub";
     TypeStore typeStore = createDynamicTypes(service, pakkage);
     String className = getTransportContext().classNames().getTransportServiceStubClassName(service);
@@ -225,10 +228,6 @@ public GapicClass generate(GapicContext context, Service service) {
     return GapicClass.create(kind, classDef);
   }
 
-  protected Transport getTransport() {
-    return Transport.GRPC;
-  }
-
   protected abstract Statement createMethodDescriptorVariableDecl(
       Service service,
       Method protoMethod,
@@ -314,7 +313,7 @@ protected List<Statement> createMethodDescriptorVariableDecls(
       Map<String, Message> messageTypes,
       boolean restNumericEnumsEnabled) {
     return service.methods().stream()
-        .filter(x -> x.isSupportedByTransport(getTransport()))
+        .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
         .map(
             m ->
                 createMethodDescriptorVariableDecl(
@@ -343,7 +342,7 @@ private static List<Statement> createClassMemberFieldDeclarations(
   protected Map<String, VariableExpr> createProtoMethodNameToDescriptorClassMembers(
       Service service, Class<?> descriptorClass) {
     return service.methods().stream()
-        .filter(x -> x.isSupportedByTransport(getTransport()))
+        .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
         .collect(
             Collectors.toMap(
                 Method::name,
@@ -375,7 +374,7 @@ private Map<String, VariableExpr> createCallableClassMembers(
     Map<String, VariableExpr> callableClassMembers = new LinkedHashMap<>();
     // Using a for-loop because the output cardinality is not a 1:1 mapping to the input set.
     for (Method protoMethod : service.methods()) {
-      if (!protoMethod.isSupportedByTransport(getTransport())) {
+      if (!protoMethod.isSupportedByTransport(getTransportContext().transport())) {
         continue;
       }
       String javaStyleProtoMethodName = JavaStyle.toLowerCamelCase(protoMethod.name());
@@ -664,7 +663,7 @@ protected List<MethodDefinition> createConstructorMethods(
     // Transport settings local variables.
     Map<String, VariableExpr> javaStyleMethodNameToTransportSettingsVarExprs =
         service.methods().stream()
-            .filter(x -> x.isSupportedByTransport(getTransport()))
+            .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
             .collect(
                 Collectors.toMap(
                     m -> JavaStyle.toLowerCamelCase(m.name()),
@@ -688,7 +687,7 @@ protected List<MethodDefinition> createConstructorMethods(
 
     secondCtorExprs.addAll(
         service.methods().stream()
-            .filter(x -> x.isSupportedByTransport(getTransport()))
+            .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
             .map(
                 m ->
                     createTransportSettingsInitExpr(
@@ -1059,7 +1058,7 @@ private List<MethodDefinition> createStubOverrideMethods(
 
   private boolean checkOperationPollingMethod(Service service) {
     return service.methods().stream()
-        .filter(x -> x.isSupportedByTransport(getTransport()))
+        .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
         .anyMatch(Method::isOperationPollingMethod);
   }
 
@@ -1098,7 +1097,7 @@ private TypeStore createDynamicTypes(Service service, String stubPakkage) {
     typeStore.putAll(
         service.pakkage(),
         service.methods().stream()
-            .filter(x -> x.isSupportedByTransport(getTransport()))
+            .filter(x -> x.isSupportedByTransport(getTransportContext().transport()))
             .filter(Method::isPaged)
             .map(m -> String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, m.name()))
             .collect(Collectors.toList()),

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceClientTestClassComposer.java

@@ -21,8 +21,6 @@
 import com.google.api.generator.gapic.composer.store.TypeStore;
 import com.google.api.generator.gapic.model.GapicClass;
 import com.google.api.generator.gapic.model.GapicContext;
-import com.google.api.generator.gapic.model.Method;
-import com.google.api.generator.gapic.model.Method.Stream;
 import com.google.api.generator.gapic.model.Service;
 import java.util.Map;
 
@@ -46,12 +44,6 @@ protected GapicClass generate(String className, GapicContext context, Service se
         service);
   }
 
-  protected boolean isSupportedMethod(Method method) {
-    return method.httpBindings() != null
-        && method.stream() != Stream.BIDI
-        && method.stream() != Stream.CLIENT;
-  }
-
   @Override
   protected MethodDefinition createStartStaticServerMethod(
       Service service,

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceStubClassComposer.java

@@ -35,6 +35,8 @@ public static HttpJsonServiceStubClassComposer instance() {
   @Override
   protected List<MethodDefinition> createStaticCreatorMethods(
       Service service, TypeStore typeStore, String newBuilderMethod) {
+    // No need to check if REST Transport is enabled
+    // AbstractTransportServiceStubClassComposer won't generate a file if REST isn't enabled
     return super.createStaticCreatorMethods(service, typeStore, "newHttpJsonBuilder");
   }
 }

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

@@ -26,6 +26,7 @@
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.model.Sample;
 import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.model.Transport;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -48,6 +49,10 @@ protected List<CommentStatement> createClassHeaderComments(
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes,
       List<Sample> samples) {
+    if (!service.hasAnyEnabledMethodsForTransport(Transport.REST)) {
+      return super.createClassHeaderComments(
+          service, typeStore, resourceNames, messageTypes, samples);
+    }
     TypeNode clientType = typeStore.get(ClassNames.getServiceClientClassName(service));
     TypeNode settingsType = typeStore.get(ClassNames.getServiceSettingsClassName(service));
     Sample classMethodSampleCode =