fix: add option to disable emulator auth handling (temp fix)

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@google-cloud/pubsub",
   "description": "Cloud Pub/Sub Client Library for Node.js",
-  "version": "4.1.0",
+  "version": "4.1.0-disable-emulator-test",
   "license": "Apache-2.0",
   "author": "Google Inc.",
   "engines": {

src/pubsub.ts

@@ -70,6 +70,7 @@ export type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
 
 export interface ClientConfig extends gax.GrpcClientOptions {
   apiEndpoint?: string;
+  useFakeCredentials?: boolean;
   servicePath?: string;
   port?: string | number;
   sslCreds?: gax.grpc.ChannelCredentials;
@@ -798,9 +799,15 @@ export class PubSub {
     // If this looks like a GCP URL of some kind, don't go into emulator
     // mode. Otherwise, supply a fake SSL provider so a real cert isn't
     // required for running the emulator.
+    //
+    // Note that users can provide their own URL here, especially with
+    // TPC, so the useFakeCredentials flag lets them override this behaviour.
     const officialUrlMatch =
       this.options.servicePath!.endsWith('.googleapis.com');
-    if (!officialUrlMatch) {
+    if (
+      (!officialUrlMatch && this.options.useFakeCredentials !== false) ||
+      this.options.useFakeCredentials === true
+    ) {
       const grpcInstance = this.options.grpc || gax.grpc;
       this.options.sslCreds = grpcInstance.credentials.createInsecure();
       this.isEmulator = true;

test/pubsub.ts

@@ -857,6 +857,30 @@ describe('PubSub', () => {
       assert.strictEqual(pubsub.isEmulator, true);
     });
 
+    it('should allow overriding fake cred mode (on)', () => {
+      pubsub!.options!.apiEndpoint = 'something.googleapis.com';
+      pubsub!.options!.useFakeCredentials = true;
+      pubsub.determineBaseUrl_?.();
+
+      assert.strictEqual(pubsub.options!.sslCreds, fakeCreds);
+      assert.strictEqual(pubsub.isEmulator, true);
+    });
+
+    it('should allow overriding fake cred mode (off)', () => {
+      const defaultBaseUrl_ = 'defaulturl';
+      const testingUrl = 'localhost:8085';
+
+      setHost(defaultBaseUrl_);
+      pubsub!.options!.apiEndpoint = testingUrl;
+      pubsub!.options!.useFakeCredentials = false;
+      pubsub.determineBaseUrl_?.();
+
+      assert.strictEqual(pubsub.options?.servicePath, 'localhost');
+      assert.strictEqual(pubsub.options.port, 8085);
+      assert.ok(pubsub.options.sslCreds === undefined);
+      assert.strictEqual(pubsub.isEmulator, false);
+    });
+
     it('should remove slashes from the baseUrl', () => {
       setHost('localhost:8080/');
       pubsub.determineBaseUrl_?.();