fix(Grpc-Web): Fix compilation failure when a service definition cont…

…ains a client streaming call. (#535)

Note this does not implement client streaming, instead the function will throw due to the feature not being implemented. This is a stop-gap until true client streaming support is added.

integration/grpc-web/example-test.ts

@@ -1,4 +1,5 @@
 import { DashStateClientImpl } from './example';
+import { EMPTY } from 'rxjs';
 
 describe('grpc-web', () => {
   it('at least compiles', () => {
@@ -19,5 +20,14 @@ describe('grpc-web', () => {
     const client = new DashStateClientImpl(rpc);
     const userSettings = client.UserSettings;
     userSettings({});
-  })
+  });
+  it('throws on client streaming call', () => {
+    const rpc = {
+      unary: jest.fn(),
+      invoke: jest.fn(),
+    };
+    const client = new DashStateClientImpl(rpc);
+    const call = () => client.ChangeUserSettingsStream(EMPTY)
+    expect(call).toThrowError("ts-proto does not yet support client streaming!")
+  });
 });

integration/grpc-web/example.proto

@@ -5,6 +5,8 @@ package rpx;
 service DashState {
   rpc UserSettings(Empty) returns (DashUserSettingsState);
   rpc ActiveUserSettingsStream(Empty) returns (stream DashUserSettingsState);
+  // not supported in grpc-web, but should still compile
+  rpc ChangeUserSettingsStream (stream DashUserSettingsState) returns (stream DashUserSettingsState) {}
 }
 
 message DashFlash {

integration/grpc-web/example.ts

@@ -595,6 +595,11 @@ export const Empty = {
 export interface DashState {
   UserSettings(request: DeepPartial<Empty>, metadata?: grpc.Metadata): Promise<DashUserSettingsState>;
   ActiveUserSettingsStream(request: DeepPartial<Empty>, metadata?: grpc.Metadata): Observable<DashUserSettingsState>;
+  /** not supported in grpc-web, but should still compile */
+  ChangeUserSettingsStream(
+    request: Observable<DeepPartial<DashUserSettingsState>>,
+    metadata?: grpc.Metadata
+  ): Observable<DashUserSettingsState>;
 }
 
 export class DashStateClientImpl implements DashState {
@@ -604,6 +609,7 @@ export class DashStateClientImpl implements DashState {
     this.rpc = rpc;
     this.UserSettings = this.UserSettings.bind(this);
     this.ActiveUserSettingsStream = this.ActiveUserSettingsStream.bind(this);
+    this.ChangeUserSettingsStream = this.ChangeUserSettingsStream.bind(this);
   }
 
   UserSettings(request: DeepPartial<Empty>, metadata?: grpc.Metadata): Promise<DashUserSettingsState> {
@@ -613,6 +619,13 @@ export class DashStateClientImpl implements DashState {
   ActiveUserSettingsStream(request: DeepPartial<Empty>, metadata?: grpc.Metadata): Observable<DashUserSettingsState> {
     return this.rpc.invoke(DashStateActiveUserSettingsStreamDesc, Empty.fromPartial(request), metadata);
   }
+
+  ChangeUserSettingsStream(
+    request: Observable<DeepPartial<DashUserSettingsState>>,
+    metadata?: grpc.Metadata
+  ): Observable<DashUserSettingsState> {
+    throw new Error('ts-proto does not yet support client streaming!');
+  }
 }
 
 export const DashStateDesc = {

src/generate-grpc-web.ts

@@ -1,5 +1,5 @@
 import { MethodDescriptorProto, FileDescriptorProto, ServiceDescriptorProto } from 'ts-proto-descriptors';
-import { requestType, responsePromiseOrObservable, responseType } from './types';
+import { rawRequestType, requestType, responsePromiseOrObservable, responseType } from './types';
 import { Code, code, imp, joinCode } from 'ts-poet';
 import { Context } from './context';
 import { assertInstanceOf, FormattedMethodDescriptor, maybePrefixPackage } from './utils';
@@ -35,33 +35,44 @@ export function generateGrpcClientImpl(
     assertInstanceOf(methodDesc, FormattedMethodDescriptor);
     chunks.push(code`this.${methodDesc.formattedName} = this.${methodDesc.formattedName}.bind(this);`);
   }
-  chunks.push(code`}\n`);
+  chunks.push(code`}`);
 
   // Create a method for each FooService method
   for (const methodDesc of serviceDesc.method) {
     chunks.push(generateRpcMethod(ctx, serviceDesc, methodDesc));
   }
 
   chunks.push(code`}`);
-  return joinCode(chunks, { trim: false });
+  return joinCode(chunks, { trim: false, on: '\n' });
 }
 
 /** Creates the RPC methods that client code actually calls. */
 function generateRpcMethod(ctx: Context, serviceDesc: ServiceDescriptorProto, methodDesc: MethodDescriptorProto) {
   assertInstanceOf(methodDesc, FormattedMethodDescriptor);
-  const { options, utils } = ctx;
-  const inputType = requestType(ctx, methodDesc);
-  const partialInputType = code`${utils.DeepPartial}<${inputType}>`;
+  const requestMessage = rawRequestType(ctx, methodDesc);
+  const inputType = requestType(ctx, methodDesc, true);
   const returns = responsePromiseOrObservable(ctx, methodDesc);
+
+  if (methodDesc.clientStreaming) {
+    return code`
+    ${methodDesc.formattedName}(
+      request: ${inputType},
+      metadata?: grpc.Metadata,
+    ): ${returns} {
+      throw new Error('ts-proto does not yet support client streaming!');
+    }
+  `;
+  }
+
   const method = methodDesc.serverStreaming ? 'invoke' : 'unary';
   return code`
     ${methodDesc.formattedName}(
-      request: ${partialInputType},
+      request: ${inputType},
       metadata?: grpc.Metadata,
     ): ${returns} {
       return this.rpc.${method}(
         ${methodDescName(serviceDesc, methodDesc)},
-        ${inputType}.fromPartial(request),
+        ${requestMessage}.fromPartial(request),
         metadata,
       );
     }

src/generate-services.ts

@@ -51,12 +51,10 @@ export function generateService(
       params.push(code`ctx: Context`);
     }
 
-    let inputType = requestType(ctx, methodDesc);
     // the grpc-web clients auto-`fromPartial` the input before handing off to grpc-web's
     // serde runtime, so it's okay to accept partial results from the client
-    if (options.outputClientImpl === 'grpc-web') {
-      inputType = code`${utils.DeepPartial}<${inputType}>`;
-    }
+    const partialInput = options.outputClientImpl === 'grpc-web';
+    const inputType = requestType(ctx, methodDesc, partialInput);
     params.push(code`request: ${inputType}`);
 
     // Use metadata as last argument for interface only configuration

src/main.ts

@@ -231,7 +231,9 @@ export function generateFile(ctx: Context, fileDesc: FileDescriptorProto): [stri
             chunks.push(generateGrpcClientImpl(ctx, fileDesc, serviceDesc));
             chunks.push(generateGrpcServiceDesc(fileDesc, serviceDesc));
             serviceDesc.method.forEach((method) => {
-              chunks.push(generateGrpcMethodDesc(ctx, serviceDesc, method));
+              if (!method.clientStreaming) {
+                chunks.push(generateGrpcMethodDesc(ctx, serviceDesc, method));
+              }
               if (method.serverStreaming) {
                 hasServerStreamingMethods = true;
               }

src/types.ts

@@ -652,8 +652,13 @@ export function rawRequestType(ctx: Context, methodDesc: MethodDescriptorProto):
   return messageToTypeName(ctx, methodDesc.inputType);
 }
 
-export function requestType(ctx: Context, methodDesc: MethodDescriptorProto): Code {
+export function requestType(ctx: Context, methodDesc: MethodDescriptorProto, partial: boolean = false): Code {
   let typeName = rawRequestType(ctx, methodDesc);
+
+  if (partial) {
+    typeName = code`${ctx.utils.DeepPartial}<${typeName}>`;
+  }
+
   if (methodDesc.clientStreaming) {
     return code`${imp('Observable@rxjs')}<${typeName}>`;
   }