fix: make browser and rest use case work

src/createApiCall.ts

@@ -55,7 +55,9 @@ import {StreamingApiCaller} from './streamingCalls/streamingApiCaller';
 export function createApiCall(
   func: Promise<GRPCCall> | GRPCCall,
   settings: CallSettings,
-  descriptor?: Descriptor
+  descriptor?: Descriptor,
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  _fallback?: boolean | 'proto' | 'rest' // unused here, used in fallback.ts implementation
 ): GaxCall {
   // we want to be able to accept both promise resolving to a function and a
   // function. Currently client librares are only calling this method with a

src/fallback.ts

@@ -46,7 +46,12 @@ import {google} from '../protos/http';
 export {FallbackServiceError};
 export {PathTemplate} from './pathTemplate';
 export {routingHeader};
-export {CallSettings, constructSettings, RetryOptions} from './gax';
+export {
+  CallSettings,
+  constructSettings,
+  RetryOptions,
+  createDefaultBackoffSettings,
+} from './gax';
 export const version = require('../../package.json').version + '-fallback';
 
 export {
@@ -58,6 +63,10 @@ export {
 
 export {StreamType} from './streamingCalls/streaming';
 
+export {OperationsClient} from './operationsClient';
+export {IamClient} from './iamService';
+export {LocationsClient} from './locationService';
+
 export const defaultToObjectOptions = {
   keepCase: false,
   longs: String,
@@ -365,16 +374,29 @@ export function lro(options: GrpcClientOptions) {
 export function createApiCall(
   func: Promise<GRPCCall> | GRPCCall,
   settings: gax.CallSettings,
-  descriptor?: Descriptor
+  descriptor?: Descriptor,
+  fallback?: boolean | 'proto' | 'rest'
 ): GaxCall {
   if (
+    (!fallback || fallback === 'rest') &&
     descriptor &&
     'streaming' in descriptor &&
     (descriptor as StreamDescriptor).type !== StreamType.SERVER_STREAMING
   ) {
     return () => {
       throw new Error(
-        'The gRPC-fallback client library (e.g. browser version of the library) currently does not support client-streaming or bidi-stream calls.'
+        'The REST transport currently does not support client-streaming or bidi-stream calls.'
+      );
+    };
+  }
+  if (
+    (fallback === 'proto' || fallback === true) && // for legacy reasons, fallback === true means 'proto'
+    descriptor &&
+    'streaming' in descriptor
+  ) {
+    return () => {
+      throw new Error(
+        'The gRPC-fallback (proto over HTTP) transport currently does not support streaming calls.'
       );
     };
   }

src/fallbackRest.ts

@@ -19,23 +19,12 @@
 import * as serializer from 'proto3-json-serializer';
 import {defaultToObjectOptions} from './fallback';
 import {FetchParameters} from './fallbackServiceStub';
-import {hasTextDecoder, hasTextEncoder, isNodeJS} from './featureDetection';
+import {hasTextDecoder, hasTextEncoder} from './featureDetection';
 import {GoogleError} from './googleError';
 import {transcode} from './transcoding';
 
 if (!hasTextEncoder() || !hasTextDecoder()) {
-  if (isNodeJS()) {
-    // Node.js 10 does not have global TextDecoder
-    // TODO(@alexander-fenster): remove this logic after Node.js 10 is EOL.
-    // eslint-disable-next-line @typescript-eslint/no-var-requires
-    const util = require('util');
-    Object.assign(global, {
-      TextDecoder: util.TextDecoder,
-      TextEncoder: util.TextEncoder,
-    });
-  } else {
-    require('fast-text-encoding');
-  }
+  require('fast-text-encoding');
 }
 
 export function encodeRequest(

src/locationService.ts

@@ -47,8 +47,6 @@ export class LocationsClient {
   private _terminated = false;
   private _opts: ClientOptions;
   private _providedCustomServicePath: boolean;
-  private _gaxGrpc: GrpcClient | FallbackGrpcClient;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   private _protos: {};
   private _defaults: {[method: string]: gax.CallSettings};
   auth: GoogleAuth;
@@ -124,14 +122,11 @@ export class LocationsClient {
       opts['scopes'] = staticMembers.scopes;
     }
 
-    // Create a `gaxGrpc` object, with any grpc-specific options sent to the client.
-    this._gaxGrpc = new GrpcClient(opts);
-
     // Save options to use in initialize() method.
     this._opts = opts;
 
     // Save the auth object to the client, for use by other methods.
-    this.auth = this._gaxGrpc.auth as GoogleAuth;
+    this.auth = gaxGrpc.auth as GoogleAuth;
 
     // Set the default scopes in auth client if needed.
     if (servicePath === staticMembers.servicePath) {
@@ -146,15 +141,15 @@ export class LocationsClient {
       clientHeader.push(`gl-web/${version}`);
     }
     if (!opts.fallback) {
-      clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
+      clientHeader.push(`grpc/${gaxGrpc.grpcVersion}`);
     } else if (opts.fallback === 'rest') {
-      clientHeader.push(`rest/${this._gaxGrpc.grpcVersion}`);
+      clientHeader.push(`rest/${gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);
     }
     // Load the applicable protos.
-    this._protos = this._gaxGrpc.loadProtoJSON(jsonProtos);
+    this._protos = gaxGrpc.loadProtoJSON(jsonProtos);
 
     // Some of the methods on this service return "paged" results,
     // (e.g. 50 results at a time, with tokens to get subsequent
@@ -168,7 +163,7 @@ export class LocationsClient {
     };
 
     // Put together the default options sent with requests.
-    this._defaults = this._gaxGrpc.constructSettings(
+    this._defaults = gaxGrpc.constructSettings(
       'google.cloud.location.Locations',
       gapicConfig as gax.ClientConfig,
       opts.clientConfig || {},