fix: return Google Error when there is a missing required parameter

src/fallbackRest.ts

@@ -56,11 +56,18 @@ export function encodeRequest(
  if (typeof json !== 'object' || Array.isArray(json)) {
  throw new Error(`Request to RPC ${rpc.name} must be an object.`);
  }
- const transcoded = transcode(
- json,
- rpc.parsedOptions,
- rpc.resolvedRequestType!.fields
- );
+
+ let transcoded;
+ try {
+ transcoded = transcode(
+ json,
+ rpc.parsedOptions,
+ rpc.resolvedRequestType!.fields
+ );
+ } catch (err) {
+ throw transcoded;
+ }
+
  if (!transcoded) {
  throw new Error(
  `Cannot build HTTP request for ${JSON.stringify(json)}, method: ${

src/fallbackServiceStub.ts

@@ -25,6 +25,7 @@ import {hasWindowFetch, hasAbortController} from './featureDetection';
 import {AuthClient} from './fallback';
 import {StreamArrayParser} from './streamArrayParser';
 import {pipeline, PipelineSource} from 'stream';
+import {GoogleError} from './googleError';
 
 interface NodeFetchType {
  (url: RequestInfo, init?: RequestInit): Promise<Response>;
@@ -37,7 +38,7 @@ export interface FallbackServiceStub {
  options: {},
  metadata: {},
  callback: (err?: Error, response?: {} | undefined) => void
- ) => StreamArrayParser | {cancel: () => void};
+ ) => StreamArrayParser | {cancel: () => void} | Promise<GoogleError>;
 }
 
 export interface FetchParameters {
@@ -91,14 +92,18 @@ export function generateServiceStub(
  : new NodeAbortController();
  const cancelSignal = cancelController.signal as AbortSignal;
  let cancelRequested = false;
-
- const fetchParameters = requestEncoder(
- rpc,
- protocol,
- servicePath,
- servicePort,
- request
- );
+ let fetchParameters: FetchParameters;
+ try {
+ fetchParameters = requestEncoder(
+ rpc,
+ protocol,
+ servicePath,
+ servicePort,
+ request
+ );
+ } catch (err) {
+ return Promise.resolve(callback(err));
+ }
  const url = fetchParameters.url;
  const headers = fetchParameters.headers;
  for (const key of Object.keys(options)) {

src/transcoding.ts

@@ -20,6 +20,7 @@
 import {JSONObject, JSONValue} from 'proto3-json-serializer';
 import {Field} from 'protobufjs';
 import {google} from '../protos/http';
+import {GoogleError} from './googleError';
 import {camelToSnakeCase, toCamelCase as snakeToCamelCase} from './util';
 
 export interface TranscodedRequest {
@@ -303,7 +304,7 @@ export function transcode(
  // all fields annotated as REQUIRED MUST be emitted in the body.
  for (const requiredField of requiredFields) {
  if (!(requiredField in request) || request[requiredField] === 'undefined') {
- throw new Error(
+ throw new GoogleError(
  `Required field ${requiredField} is not present in the request.`
  );
  }

test/browser-test/test.grpc-fallback.ts

@@ -23,6 +23,7 @@ import * as protobuf from 'protobufjs';
 import * as sinon from 'sinon';
 
 import * as fallback from '../../src/fallback';
+import {StreamArrayParser} from '../../src/streamArrayParser';
 import {echoProtoJson} from '../fixtures/echoProtoJson';
 import {EchoClient} from '../fixtures/google-gax-packaging-test-app/src/v1beta1/echo_client';
 
@@ -220,7 +221,7 @@ describe('grpc-fallback', () => {
  const request = {content: 'content' + new Date().toString()};
  const call = echoStub.echo(request, {}, {}, () => {});
 
- call.cancel();
+ (call as StreamArrayParser).cancel();
 
  // @ts-ignore
  assert.strictEqual(createdAbortControllers[0].abortCalled, true);

test/unit/grpc-fallback.ts

@@ -28,6 +28,7 @@ import * as sinon from 'sinon';
 import {echoProtoJson} from '../fixtures/echoProtoJson';
 import {GrpcClient} from '../../src/fallback';
 import {GoogleError} from '../../src';
+import {StreamArrayParser} from '../../src/streamArrayParser';
 
 // @ts-ignore
 const hasAbortController = typeof AbortController !== 'undefined';
@@ -414,7 +415,7 @@ describe('grpc-fallback', () => {
  const request = {content: 'content' + new Date().toString()};
  const call = echoStub.echo(request, {}, {}, () => {});
 
- call.cancel();
+ (call as StreamArrayParser).cancel();
 
  // @ts-ignore
  assert.strictEqual(createdAbortControllers[0].abortCalled, true);

test/unit/transcoding.ts

@@ -32,6 +32,7 @@ import {
  buildQueryStringComponents,
  requestChangeCaseAndCleanup,
  overrideHttpRules,
+ TranscodedRequest,
 } from '../../src/transcoding';
 import * as assert from 'assert';
 import {
@@ -42,6 +43,7 @@ import * as protobuf from 'protobufjs';
 import {testMessageJson} from '../fixtures/fallbackOptional';
 import {echoProtoJson} from '../fixtures/echoProtoJson';
 import {google} from '../../protos/http';
+import {GoogleError} from '../../src';
 
 describe('gRPC to HTTP transcoding', () => {
  const parsedOptions: ParsedOptionsType = [
@@ -594,7 +596,7 @@ describe('validate proto3 field with default value', () => {
  ];
  const transcoded = transcode(request, parsedOptions, badTestMessageFields);
  assert.deepStrictEqual(
- transcoded?.url,
+ (transcoded as TranscodedRequest)?.url,
  'projects/test-project/contents/test-content'
  );
  });
@@ -622,7 +624,7 @@ describe('validate proto3 field with default value', () => {
  for (const request of requests) {
  assert.throws(
  () => transcode(request, parsedOptions, testMessageFields),
- Error
+ /Error: Required field content is not present in the request/
  );
  }
  });
@@ -640,8 +642,13 @@ describe('validate proto3 field with default value', () => {
  },
  ];
  const transcoded = transcode(request, parsedOptions, testMessageFields);
- assert.deepStrictEqual(transcoded?.url, 'projects/test-project');
- assert.deepStrictEqual(transcoded?.data, {content: 'test-content'});
+ assert.deepStrictEqual(
+ (transcoded as TranscodedRequest)?.url,
+ 'projects/test-project'
+ );
+ assert.deepStrictEqual((transcoded as TranscodedRequest)?.data, {
+ content: 'test-content',
+ });
  });
  it('when body="*", unset optional field should remove from body', () => {
  const requests: RequestType[] = [
@@ -666,10 +673,10 @@ describe('validate proto3 field with default value', () => {
  for (const request of requests) {
  const transcoded = transcode(request, parsedOptions, testMessageFields);
  assert.deepStrictEqual(
- transcoded?.url,
+ (transcoded as TranscodedRequest)?.url,
  'projects/test-project/contents/test-content'
  );
- assert.deepStrictEqual(transcoded?.data, {});
+ assert.deepStrictEqual((transcoded as TranscodedRequest)?.data, {});
  }
  });
  it('unset optional fields should not appear in query params', () => {
@@ -697,9 +704,15 @@ describe('validate proto3 field with default value', () => {
  ];
  for (const request of requests) {
  const transcoded = transcode(request, parsedOptions, testMessageFields);
- assert.deepStrictEqual(transcoded?.url, 'projects/test-project');
- assert.deepStrictEqual(transcoded?.data, 'test-content');
- assert.deepStrictEqual(transcoded.queryString, '');
+ assert.deepStrictEqual(
+ (transcoded as TranscodedRequest)?.url,
+ 'projects/test-project'
+ );
+ assert.deepStrictEqual(
+ (transcoded as TranscodedRequest)?.data,
+ 'test-content'
+ );
+ assert.deepStrictEqual((transcoded as TranscodedRequest).queryString, '');
  }
  });
 });