[CodeGenLib] Remove namespace enum generation (#1808)

Motivation:

Having a namespace enum in the generated code leads to redeclaration of the package enum
when we generate code for .proto files within the same package. Thus, we cannot generate the
namespace enums anymore, so we need to generate service enums that contain the namespace in their names.

Modifications:

- Changed the typealias translator to generate the service enums with namespace prefixed names
- Deleted the namespace enum generation
- Modified the CodeGenerationRequest validation function for service names
- Updated tests accordingly

Result:

Redeclaration of the same enum will be avoided when generating code using CodeGenLib.

Co-authored-by: George Barnett <gbarnett@apple.com>

Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift

@@ -58,26 +58,24 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         import DifferentModule
         import ExtraModule
 
-        internal enum Helloworld {
-            internal enum Greeter {
-                internal enum Method {
-                    internal enum SayHello {
-                        internal typealias Input = Helloworld_HelloRequest
-                        internal typealias Output = Helloworld_HelloReply
-                        internal static let descriptor = MethodDescriptor(
-                            service: "helloworld.Greeter",
-                            method: "SayHello"
-                        )
-                    }
-                    internal static let descriptors: [MethodDescriptor] = [
-                        SayHello.descriptor
-                    ]
+        internal enum Helloworld_Greeter {
+            internal enum Method {
+                internal enum SayHello {
+                    internal typealias Input = Helloworld_HelloRequest
+                    internal typealias Output = Helloworld_HelloReply
+                    internal static let descriptor = MethodDescriptor(
+                        service: "helloworld.Greeter",
+                        method: "SayHello"
+                    )
                 }
-                @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-                internal typealias ClientProtocol = Helloworld_GreeterClientProtocol
-                @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-                internal typealias Client = Helloworld_GreeterClient
+                internal static let descriptors: [MethodDescriptor] = [
+                    SayHello.descriptor
+                ]
             }
+            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+            internal typealias ClientProtocol = Helloworld_GreeterClientProtocol
+            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+            internal typealias Client = Helloworld_GreeterClient
         }
 
         /// The greeting service definition.
@@ -85,23 +83,23 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         internal protocol Helloworld_GreeterClientProtocol: Sendable {
             /// Sends a greeting.
             func sayHello<R>(
-                request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-                serializer: some MessageSerializer<Helloworld.Greeter.Method.SayHello.Input>,
-                deserializer: some MessageDeserializer<Helloworld.Greeter.Method.SayHello.Output>,
-                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+                request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+                serializer: some MessageSerializer<Helloworld_Greeter.Method.SayHello.Input>,
+                deserializer: some MessageDeserializer<Helloworld_Greeter.Method.SayHello.Output>,
+                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
             ) async throws -> R where R: Sendable
         }
 
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.ClientProtocol {
+        extension Helloworld_Greeter.ClientProtocol {
             internal func sayHello<R>(
-                request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+                request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
             ) async throws -> R where R: Sendable {
                 try await self.sayHello(
                     request: request,
-                    serializer: ProtobufSerializer<Helloworld.Greeter.Method.SayHello.Input>(),
-                    deserializer: ProtobufDeserializer<Helloworld.Greeter.Method.SayHello.Output>(),
+                    serializer: ProtobufSerializer<Helloworld_Greeter.Method.SayHello.Input>(),
+                    deserializer: ProtobufDeserializer<Helloworld_Greeter.Method.SayHello.Output>(),
                     body
                 )
             }
@@ -109,7 +107,7 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        internal struct Helloworld_GreeterClient: Helloworld.Greeter.ClientProtocol {
+        internal struct Helloworld_GreeterClient: Helloworld_Greeter.ClientProtocol {
             private let client: GRPCCore.GRPCClient
             
             internal init(client: GRPCCore.GRPCClient) {
@@ -118,14 +116,14 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
             
             /// Sends a greeting.
             internal func sayHello<R>(
-                request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-                serializer: some MessageSerializer<Helloworld.Greeter.Method.SayHello.Input>,
-                deserializer: some MessageDeserializer<Helloworld.Greeter.Method.SayHello.Output>,
-                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+                request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+                serializer: some MessageSerializer<Helloworld_Greeter.Method.SayHello.Input>,
+                deserializer: some MessageDeserializer<Helloworld_Greeter.Method.SayHello.Output>,
+                _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
             ) async throws -> R where R: Sendable {
                 try await self.client.unary(
                     request: request,
-                    descriptor: Helloworld.Greeter.Method.SayHello.descriptor,
+                    descriptor: Helloworld_Greeter.Method.SayHello.descriptor,
                     serializer: serializer,
                     deserializer: deserializer,
                     handler: body
@@ -169,44 +167,42 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         import DifferentModule
         import ExtraModule
 
-        public enum Helloworld {
-          public enum Greeter {
-            public enum Method {
-              public enum SayHello {
-                public typealias Input = Helloworld_HelloRequest
-                public typealias Output = Helloworld_HelloReply
-                public static let descriptor = MethodDescriptor(
-                  service: "helloworld.Greeter",
-                  method: "SayHello"
-                )
-              }
-              public static let descriptors: [MethodDescriptor] = [
-                SayHello.descriptor
-              ]
+        public enum Helloworld_Greeter {
+          public enum Method {
+            public enum SayHello {
+              public typealias Input = Helloworld_HelloRequest
+              public typealias Output = Helloworld_HelloReply
+              public static let descriptor = MethodDescriptor(
+                service: "helloworld.Greeter",
+                method: "SayHello"
+              )
             }
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            public typealias StreamingServiceProtocol = Helloworld_GreeterStreamingServiceProtocol
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            public typealias ServiceProtocol = Helloworld_GreeterServiceProtocol
+            public static let descriptors: [MethodDescriptor] = [
+              SayHello.descriptor
+            ]
           }
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          public typealias StreamingServiceProtocol = Helloworld_GreeterStreamingServiceProtocol
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          public typealias ServiceProtocol = Helloworld_GreeterServiceProtocol
         }
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         public protocol Helloworld_GreeterStreamingServiceProtocol: GRPCCore.RegistrableRPCService {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Stream<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld.Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output>
         }
 
         /// Conformance to `GRPCCore.RegistrableRPCService`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.StreamingServiceProtocol {
+        extension Helloworld_Greeter.StreamingServiceProtocol {
           @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
           public func registerMethods(with router: inout GRPCCore.RPCRouter) {
             router.registerHandler(
-              forMethod: Helloworld.Greeter.Method.SayHello.descriptor,
-              deserializer: ProtobufDeserializer<Helloworld.Greeter.Method.SayHello.Input>(),
-              serializer: ProtobufSerializer<Helloworld.Greeter.Method.SayHello.Output>(),
+              forMethod: Helloworld_Greeter.Method.SayHello.descriptor,
+              deserializer: ProtobufDeserializer<Helloworld_Greeter.Method.SayHello.Input>(),
+              serializer: ProtobufSerializer<Helloworld_Greeter.Method.SayHello.Output>(),
               handler: { request in
                 try await self.sayHello(request: request)
               }
@@ -216,15 +212,15 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        public protocol Helloworld_GreeterServiceProtocol: Helloworld.Greeter.StreamingServiceProtocol {
+        public protocol Helloworld_GreeterServiceProtocol: Helloworld_Greeter.StreamingServiceProtocol {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Single<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Helloworld.Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Single<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Helloworld_Greeter.Method.SayHello.Output>
         }
 
         /// Partial conformance to `Helloworld_GreeterStreamingServiceProtocol`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.ServiceProtocol {
-          public func sayHello(request: ServerRequest.Stream<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld.Greeter.Method.SayHello.Output> {
+        extension Helloworld_Greeter.ServiceProtocol {
+          public func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output> {
             let response = try await self.sayHello(request: ServerRequest.Single(stream: request))
             return ServerResponse.Stream(single: response)
           }
@@ -265,48 +261,46 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         import DifferentModule
         import ExtraModule
 
-        package enum Helloworld {
-          package enum Greeter {
-            package enum Method {
-              package enum SayHello {
-                package typealias Input = Helloworld_HelloRequest
-                package typealias Output = Helloworld_HelloReply
-                package static let descriptor = MethodDescriptor(
-                  service: "helloworld.Greeter",
-                  method: "SayHello"
-                )
-              }
-              package static let descriptors: [MethodDescriptor] = [
-                SayHello.descriptor
-              ]
+        package enum Helloworld_Greeter {
+          package enum Method {
+            package enum SayHello {
+              package typealias Input = Helloworld_HelloRequest
+              package typealias Output = Helloworld_HelloReply
+              package static let descriptor = MethodDescriptor(
+                service: "helloworld.Greeter",
+                method: "SayHello"
+              )
             }
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            package typealias StreamingServiceProtocol = Helloworld_GreeterStreamingServiceProtocol
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            package typealias ServiceProtocol = Helloworld_GreeterServiceProtocol
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            package typealias ClientProtocol = Helloworld_GreeterClientProtocol
-            @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-            package typealias Client = Helloworld_GreeterClient
+            package static let descriptors: [MethodDescriptor] = [
+              SayHello.descriptor
+            ]
           }
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          package typealias StreamingServiceProtocol = Helloworld_GreeterStreamingServiceProtocol
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          package typealias ServiceProtocol = Helloworld_GreeterServiceProtocol
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          package typealias ClientProtocol = Helloworld_GreeterClientProtocol
+          @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
+          package typealias Client = Helloworld_GreeterClient
         }
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
         package protocol Helloworld_GreeterStreamingServiceProtocol: GRPCCore.RegistrableRPCService {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Stream<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld.Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output>
         }
 
         /// Conformance to `GRPCCore.RegistrableRPCService`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.StreamingServiceProtocol {
+        extension Helloworld_Greeter.StreamingServiceProtocol {
           @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
           package func registerMethods(with router: inout GRPCCore.RPCRouter) {
             router.registerHandler(
-              forMethod: Helloworld.Greeter.Method.SayHello.descriptor,
-              deserializer: ProtobufDeserializer<Helloworld.Greeter.Method.SayHello.Input>(),
-              serializer: ProtobufSerializer<Helloworld.Greeter.Method.SayHello.Output>(),
+              forMethod: Helloworld_Greeter.Method.SayHello.descriptor,
+              deserializer: ProtobufDeserializer<Helloworld_Greeter.Method.SayHello.Input>(),
+              serializer: ProtobufSerializer<Helloworld_Greeter.Method.SayHello.Output>(),
               handler: { request in
                 try await self.sayHello(request: request)
               }
@@ -316,15 +310,15 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        package protocol Helloworld_GreeterServiceProtocol: Helloworld.Greeter.StreamingServiceProtocol {
+        package protocol Helloworld_GreeterServiceProtocol: Helloworld_Greeter.StreamingServiceProtocol {
           /// Sends a greeting.
-          func sayHello(request: ServerRequest.Single<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Helloworld.Greeter.Method.SayHello.Output>
+          func sayHello(request: ServerRequest.Single<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Single<Helloworld_Greeter.Method.SayHello.Output>
         }
 
         /// Partial conformance to `Helloworld_GreeterStreamingServiceProtocol`.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.ServiceProtocol {
-          package func sayHello(request: ServerRequest.Stream<Helloworld.Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld.Greeter.Method.SayHello.Output> {
+        extension Helloworld_Greeter.ServiceProtocol {
+          package func sayHello(request: ServerRequest.Stream<Helloworld_Greeter.Method.SayHello.Input>) async throws -> ServerResponse.Stream<Helloworld_Greeter.Method.SayHello.Output> {
             let response = try await self.sayHello(request: ServerRequest.Single(stream: request))
             return ServerResponse.Stream(single: response)
           }
@@ -335,23 +329,23 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
         package protocol Helloworld_GreeterClientProtocol: Sendable {
           /// Sends a greeting.
           func sayHello<R>(
-            request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-            serializer: some MessageSerializer<Helloworld.Greeter.Method.SayHello.Input>,
-            deserializer: some MessageDeserializer<Helloworld.Greeter.Method.SayHello.Output>,
-            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+            request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+            serializer: some MessageSerializer<Helloworld_Greeter.Method.SayHello.Input>,
+            deserializer: some MessageDeserializer<Helloworld_Greeter.Method.SayHello.Output>,
+            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
           ) async throws -> R where R: Sendable
         }
 
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        extension Helloworld.Greeter.ClientProtocol {
+        extension Helloworld_Greeter.ClientProtocol {
           package func sayHello<R>(
-            request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+            request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
           ) async throws -> R where R: Sendable {
             try await self.sayHello(
               request: request,
-              serializer: ProtobufSerializer<Helloworld.Greeter.Method.SayHello.Input>(),
-              deserializer: ProtobufDeserializer<Helloworld.Greeter.Method.SayHello.Output>(),
+              serializer: ProtobufSerializer<Helloworld_Greeter.Method.SayHello.Input>(),
+              deserializer: ProtobufDeserializer<Helloworld_Greeter.Method.SayHello.Output>(),
               body
             )
           }
@@ -359,7 +353,7 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
 
         /// The greeting service definition.
         @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
-        package struct Helloworld_GreeterClient: Helloworld.Greeter.ClientProtocol {
+        package struct Helloworld_GreeterClient: Helloworld_Greeter.ClientProtocol {
           private let client: GRPCCore.GRPCClient
           
           package init(client: GRPCCore.GRPCClient) {
@@ -368,14 +362,14 @@ final class ProtobufCodeGeneratorTests: XCTestCase {
           
           /// Sends a greeting.
           package func sayHello<R>(
-            request: ClientRequest.Single<Helloworld.Greeter.Method.SayHello.Input>,
-            serializer: some MessageSerializer<Helloworld.Greeter.Method.SayHello.Input>,
-            deserializer: some MessageDeserializer<Helloworld.Greeter.Method.SayHello.Output>,
-            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld.Greeter.Method.SayHello.Output>) async throws -> R
+            request: ClientRequest.Single<Helloworld_Greeter.Method.SayHello.Input>,
+            serializer: some MessageSerializer<Helloworld_Greeter.Method.SayHello.Input>,
+            deserializer: some MessageDeserializer<Helloworld_Greeter.Method.SayHello.Output>,
+            _ body: @Sendable @escaping (ClientResponse.Single<Helloworld_Greeter.Method.SayHello.Output>) async throws -> R
           ) async throws -> R where R: Sendable {
             try await self.client.unary(
               request: request,
-              descriptor: Helloworld.Greeter.Method.SayHello.descriptor,
+              descriptor: Helloworld_Greeter.Method.SayHello.descriptor,
               serializer: serializer,
               deserializer: deserializer,
               handler: body