fix(microservice): grpc-client serialize error

closes #10104

integration/microservices/e2e/sum-grpc.spec.ts

@@ -60,6 +60,18 @@ describe('GRPC transport', () => {
       .expect(200, { result: 15 });
   });
 
+  it(`GRPC Receiving serialized Error`, async () => {
+    await request(server)
+      .post('/error?client=standard')
+      .expect(200)
+      .expect('false');
+
+    await request(server)
+      .post('/error?client=custom')
+      .expect(200)
+      .expect('true');
+  });
+
   it(`GRPC Sending and Receiving HTTP POST (multiple proto)`, async () => {
     await request(server)
       .post('/multi/sum')

integration/microservices/src/grpc/grpc.controller.ts

@@ -1,4 +1,4 @@
-import { Body, Controller, HttpCode, Post } from '@nestjs/common';
+import { Body, Controller, HttpCode, Post, Query } from '@nestjs/common';
 import {
   Client,
   ClientGrpc,
@@ -6,12 +6,28 @@ import {
   GrpcStreamCall,
   GrpcStreamMethod,
   Transport,
+  ClientGrpcProxy,
+  RpcException,
 } from '@nestjs/microservices';
 import { join } from 'path';
-import { Observable, of } from 'rxjs';
+import { Observable, of, catchError } from 'rxjs';
+
+class ErrorHandlingProxy extends ClientGrpcProxy {
+  serializeError(err) {
+    return new RpcException(err);
+  }
+}
 
 @Controller()
 export class GrpcController {
+  private readonly customClient: ClientGrpc;
+  constructor() {
+    this.customClient = new ErrorHandlingProxy({
+      package: 'math',
+      protoPath: join(__dirname, 'math.proto'),
+    });
+  }
+
   @Client({
     transport: Transport.GRPC,
     options: {
@@ -78,6 +94,19 @@ export class GrpcController {
     });
   }
 
+  @GrpcMethod('Math')
+  async divide(request: { dividend: number; divisor: number }): Promise<any> {
+    if (request.divisor === 0) {
+      throw new RpcException({
+        code: 3,
+        message: 'dividing by 0 is not possible',
+      });
+    }
+    return {
+      result: request.dividend / request.divisor,
+    };
+  }
+
   @GrpcMethod('Math2')
   async sum2({ data }: { data: number[] }): Promise<any> {
     return of({
@@ -98,4 +127,24 @@ export class GrpcController {
     const svc = this.clientMulti.getService<any>('Math2');
     return svc.sum2({ data });
   }
+
+  @Post('error')
+  @HttpCode(200)
+  serializeError(
+    @Query('client') query: 'custom' | 'standard' = 'standard',
+    @Body() body: Record<string, any>,
+  ): Observable<boolean> {
+    const client = query === 'custom' ? this.customClient : this.client;
+    const svc = client.getService<any>('Math');
+
+    const errorDivideRequest = {
+      dividend: 1,
+      divisor: 0,
+    };
+    return svc.divide(errorDivideRequest).pipe(
+      catchError(err => {
+        return of(err instanceof RpcException);
+      }),
+    );
+  }
 }

integration/microservices/src/grpc/math.proto

@@ -6,6 +6,7 @@ service Math {
   rpc Sum (RequestSum) returns (SumResult);
   rpc SumStream(stream RequestSum) returns(stream SumResult);
   rpc SumStreamPass(stream RequestSum) returns(stream SumResult);
+  rpc Divide (RequestDivide) returns (DivideResult);
 }
 
 message SumResult {
@@ -14,4 +15,13 @@ message SumResult {
 
 message RequestSum {
   repeated int32 data = 1;
-}
+}
+
+message RequestDivide {
+  int32 dividend = 1;
+  int32 divisor = 2 ;
+}
+
+message DivideResult {
+  int32 result = 1;
+}