Merge pull request #8 from hfour/goce/H4C-246_error_handling_rpc_module

H4C-246: Error handling in the JSONRpc module

Author: spion-h4

src/index.spec.ts

@@ -34,6 +34,22 @@ describe("json-rpc-e2e", () => {
       });
   });
 
+  it(`should throw an error on /rpc/v1/ test.testError (POST)`, () => {
+    const errorObj = {
+      message: "RPC EXCEPTION",
+      code: 403,
+      data: {
+        fromService: "Test Service",
+        params: { data: "hi" }
+      }
+    };
+    return request(server.server)
+      .post("/rpc/v1")
+      .send({ method: "test.testError", params: { data: "hi" } })
+      .expect(403)
+      .expect(errorObj);
+  });
+
   afterAll(async () => {
     await app.close();
   });

src/index.ts

@@ -1,7 +1,7 @@
 import * as express from "express";
 import * as http from "http";
 
-import { Server, CustomTransportStrategy } from "@nestjs/microservices";
+import { Server, CustomTransportStrategy, RpcException } from "@nestjs/microservices";
 import { Injectable, Controller } from "@nestjs/common";
 import { MessagePattern } from "@nestjs/microservices";
 
@@ -21,8 +21,8 @@ export interface JSONRPCServerOptions {
    */
   hostname?: string;
   /*
-      * The path at which the JSON RPC endpoint should be mounted
-      */
+   * The path at which the JSON RPC endpoint should be mounted
+   */
   path: string;
 }
 
@@ -74,7 +74,10 @@ export class JSONRPCServer extends Server implements CustomTransportStrategy {
         );
 
       if ("error" in response) {
-        res.status(500).json({ error: response.error.message })
+        let resp = { code: 500, message: response.error.message, data: undefined };
+        if ("code" in response.error) resp.code = response.error.code;
+        if ("data" in response.error) resp.data = response.error.data;
+        res.status(resp.code).json(resp);
       } else {
         res.status(200).json(response.value);
       }
@@ -96,3 +99,9 @@ export class JSONRPCServer extends Server implements CustomTransportStrategy {
     // do nothing, maybe block further requests
   }
 }
+
+export class CodedRpcException extends RpcException {
+  constructor(message: string, public code: number = 500, public data: any = {}) {
+    super({ message, code, data });
+  }
+}

src/test-handler.ts

@@ -12,7 +12,7 @@ import {
   Scope
 } from "@nestjs/common";
 
-import { JSONRpcService } from ".";
+import { JSONRpcService, CodedRpcException } from ".";
 
 const initialModuleState = {
   pipeCalled: false,
@@ -77,4 +77,12 @@ export class TestService {
     console.log("Invoke WAS called");
     return params;
   }
+
+  @UsePipes(TestPipe)
+  @UseInterceptors(TestInterceptor)
+  @UseGuards(TestGuard)
+  public async testError(params: any) {
+    // construct the error object with some data inside
+    throw new CodedRpcException("RPC EXCEPTION", 403, { fromService: "Test Service", params });
+  }
 }