Fixed issue where multiple calls to connectDataConnectEmulator causes an exception

.changeset/funny-weeks-attack.md

@@ -0,0 +1,5 @@
+---
+"@firebase/data-connect": patch
+---
+
+Fixed issue where multiple calls to connectDataConnectEmulator caused an exception

packages/data-connect/src/api/DataConnect.ts

@@ -179,7 +179,10 @@ export class DataConnect {
 
   // @internal
   enableEmulator(transportOptions: TransportOptions): void {
-    if (this._initialized) {
+    if (
+      this._initialized &&
+      !areTransportOptionsEqual(this._transportOptions, transportOptions)
+    ) {
       logError('enableEmulator called after initialization');
       throw new DataConnectError(
         Code.ALREADY_INITIALIZED,
@@ -191,6 +194,23 @@ export class DataConnect {
   }
 }
 
+/**
+ * @internal
+ * @param transportOptions1
+ * @param transportOptions2
+ * @returns
+ */
+export function areTransportOptionsEqual(
+  transportOptions1: TransportOptions,
+  transportOptions2: TransportOptions
+): boolean {
+  return (
+    transportOptions1.host === transportOptions2.host &&
+    transportOptions1.port === transportOptions2.port &&
+    transportOptions1.sslEnabled === transportOptions2.sslEnabled
+  );
+}
+
 /**
  * Connect to the DataConnect Emulator
  * @param dc Data Connect instance

packages/data-connect/test/unit/transportoptions.test.ts

@@ -0,0 +1,80 @@
+/**
+ * @license
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { expect } from 'chai';
+import {
+  TransportOptions,
+  areTransportOptionsEqual,
+  connectDataConnectEmulator,
+  getDataConnect
+} from '../../src/api/DataConnect';
+import { app } from '../util';
+import { queryRef } from '../../src';
+describe('Transport Options', () => {
+  it('should return false if transport options are not equal', () => {
+    const transportOptions1: TransportOptions = {
+      host: 'h',
+      port: 1,
+      sslEnabled: false
+    };
+    const transportOptions2: TransportOptions = {
+      host: 'h2',
+      port: 2,
+      sslEnabled: false
+    };
+    expect(
+      areTransportOptionsEqual(transportOptions1, transportOptions2)
+    ).to.eq(false);
+  });
+  it('should return true if transport options are equal', () => {
+    const transportOptions1: TransportOptions = {
+      host: 'h',
+      port: 1,
+      sslEnabled: false
+    };
+    const transportOptions2: TransportOptions = {
+      port: 1,
+      host: 'h',
+      sslEnabled: false
+    };
+    expect(
+      areTransportOptionsEqual(transportOptions1, transportOptions2)
+    ).to.eq(true);
+  });
+  it('should throw if emulator is connected to with new transport options', () => {
+    const dc = getDataConnect(app, {
+      connector: 'c',
+      location: 'l',
+      service: 's'
+    });
+    expect(() => connectDataConnectEmulator(dc, 'h', 80, false)).to.not.throw();
+    queryRef(dc, 'query');
+    expect(() => connectDataConnectEmulator(dc, 'h2', 80, false)).to.throw(
+      'DataConnect instance already initialized!'
+    );
+  });
+  it('should not throw if emulator is connected to with the same transport options', () => {
+    const dc = getDataConnect(app, {
+      connector: 'c',
+      location: 'l',
+      service: 's'
+    });
+    expect(() => connectDataConnectEmulator(dc, 'h', 80, false)).to.not.throw();
+    queryRef(dc, 'query');
+    expect(() => connectDataConnectEmulator(dc, 'h', 80, false)).to.not.throw();
+  });
+});