fix: regression in being able to return a Date as a GRPC return value

integration/use-date-true/google/protobuf/empty.ts

@@ -0,0 +1,81 @@
+/* eslint-disable */
+import { util, configure, Writer, Reader } from 'protobufjs/minimal';
+import * as Long from 'long';
+
+export const protobufPackage = 'google.protobuf';
+
+/**
+ * A generic empty message that you can re-use to avoid defining duplicated
+ * empty messages in your APIs. A typical example is to use it as the request
+ * or the response type of an API method. For instance:
+ *
+ *     service Foo {
+ *       rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);
+ *     }
+ *
+ * The JSON representation for `Empty` is empty JSON object `{}`.
+ */
+export interface Empty {}
+
+function createBaseEmpty(): Empty {
+  return {};
+}
+
+export const Empty = {
+  encode(_: Empty, writer: Writer = Writer.create()): Writer {
+    return writer;
+  },
+
+  decode(input: Reader | Uint8Array, length?: number): Empty {
+    const reader = input instanceof Reader ? input : new Reader(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseEmpty();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        default:
+          reader.skipType(tag & 7);
+          break;
+      }
+    }
+    return message;
+  },
+
+  fromJSON(_: any): Empty {
+    return {};
+  },
+
+  toJSON(_: Empty): unknown {
+    const obj: any = {};
+    return obj;
+  },
+
+  fromPartial<I extends Exact<DeepPartial<Empty>, I>>(_: I): Empty {
+    const message = createBaseEmpty();
+    return message;
+  },
+};
+
+type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
+
+export type DeepPartial<T> = T extends Builtin
+  ? T
+  : T extends Array<infer U>
+  ? Array<DeepPartial<U>>
+  : T extends ReadonlyArray<infer U>
+  ? ReadonlyArray<DeepPartial<U>>
+  : T extends {}
+  ? { [K in keyof T]?: DeepPartial<T[K]> }
+  : Partial<T>;
+
+type KeysOfUnion<T> = T extends T ? keyof T : never;
+export type Exact<P, I extends P> = P extends Builtin
+  ? P
+  : P & { [K in keyof P]: Exact<P[K], I[K]> } & Record<Exclude<keyof I, KeysOfUnion<P>>, never>;
+
+// If you get a compile-error about 'Constructor<Long> and ... have no overlap',
+// add '--ts_proto_opt=esModuleInterop=true' as a flag when calling 'protoc'.
+if (util.Long !== Long) {
+  util.Long = Long as any;
+  configure();
+}

integration/use-date-true/parameters.txt

@@ -1 +1 @@
-useDate=true
+useDate=true,outputServices=generic-definitions,outputServices=default

integration/use-date-true/use-date-true-test.ts

@@ -1,9 +1,14 @@
-import { Todo } from './use-date-true';
+import { Todo, Clock } from './use-date-true';
 
 const jan1 = new Date('1970-01-01T00:00:00.000Z');
 const feb1 = new Date('1970-02-01T00:00:00.000Z');
 
 describe('useDate=true', () => {
+  it('generates a services that compiles', () => {
+    let c: Clock = {
+      Now: () => Promise.resolve(jan1),
+    };
+  });
   it('generates types that compile and encode', () => {
     const output = Todo.encode({
       id: '6883ed6e-bd0d-4817-ba58-c2a53c73edc2',

integration/use-date-true/use-date-true.proto

@@ -1,4 +1,5 @@
 syntax = "proto3";
+import "google/protobuf/empty.proto";
 import "google/protobuf/timestamp.proto";
 
 message Todo {
@@ -8,3 +9,7 @@ message Todo {
   optional google.protobuf.Timestamp optional_timestamp = 4;
   map<string, google.protobuf.Timestamp> map_of_timestamps = 5;
 }
+
+service Clock {
+  rpc Now(google.protobuf.Empty) returns (google.protobuf.Timestamp);
+}

integration/use-date-true/use-date-true.ts

@@ -2,6 +2,7 @@
 import { util, configure, Writer, Reader } from 'protobufjs/minimal';
 import * as Long from 'long';
 import { Timestamp } from './google/protobuf/timestamp';
+import { Empty } from './google/protobuf/empty';
 
 export const protobufPackage = '';
 
@@ -188,6 +189,42 @@ export const Todo_MapOfTimestampsEntry = {
   },
 };
 
+export interface Clock {
+  Now(request: Empty): Promise<Date>;
+}
+
+export class ClockClientImpl implements Clock {
+  private readonly rpc: Rpc;
+  constructor(rpc: Rpc) {
+    this.rpc = rpc;
+    this.Now = this.Now.bind(this);
+  }
+  Now(request: Empty): Promise<Date> {
+    const data = Empty.encode(request).finish();
+    const promise = this.rpc.request('Clock', 'Now', data);
+    return promise.then((data) => fromTimestamp(Timestamp.decode(new Reader(data))));
+  }
+}
+
+export const ClockDefinition = {
+  name: 'Clock',
+  fullName: 'Clock',
+  methods: {
+    now: {
+      name: 'Now',
+      requestType: Empty,
+      requestStream: false,
+      responseType: Timestamp,
+      responseStream: false,
+      options: {},
+    },
+  },
+} as const;
+
+interface Rpc {
+  request(service: string, method: string, data: Uint8Array): Promise<Uint8Array>;
+}
+
 type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
 
 export type DeepPartial<T> = T extends Builtin

src/generate-services.ts

@@ -106,18 +106,22 @@ function generateRegularRpcMethod(
   methodDesc: MethodDescriptorProto
 ): Code {
   assertInstanceOf(methodDesc, FormattedMethodDescriptor);
-  const { options } = ctx;
+  const { options, utils } = ctx;
   const Reader = imp('Reader@protobufjs/minimal');
   const rawInputType = rawRequestType(ctx, methodDesc);
   const inputType = requestType(ctx, methodDesc);
   const outputType = responseType(ctx, methodDesc);
+  const rawOutputType = responseType(ctx, methodDesc, { keepValueType: true });
 
   const params = [...(options.context ? [code`ctx: Context`] : []), code`request: ${inputType}`];
   const maybeCtx = options.context ? 'ctx,' : '';
 
   let encode = code`${rawInputType}.encode(request).finish()`;
   let decode = code`data => ${outputType}.decode(new ${Reader}(data))`;
-
+  console.error();
+  if (options.useDate && rawOutputType.toString().includes('Timestamp')) {
+    decode = code`data => ${utils.fromTimestamp}(${rawOutputType}.decode(new ${Reader}(data)))`;
+  }
   if (methodDesc.clientStreaming) {
     encode = code`request.pipe(${imp('map@rxjs/operators')}(request => ${encode}))`;
   }

src/types.ts

@@ -660,8 +660,12 @@ export function requestType(ctx: Context, methodDesc: MethodDescriptorProto): Co
   return typeName;
 }
 
-export function responseType(ctx: Context, methodDesc: MethodDescriptorProto): Code {
-  return messageToTypeName(ctx, methodDesc.outputType, { keepValueType: true });
+export function responseType(
+  ctx: Context,
+  methodDesc: MethodDescriptorProto,
+  typeOptions: { keepValueType?: boolean; repeated?: boolean } = {}
+): Code {
+  return messageToTypeName(ctx, methodDesc.outputType, typeOptions);
 }
 
 export function responsePromise(ctx: Context, methodDesc: MethodDescriptorProto): Code {