Used warning instead of throwing error

Author: maneesht

packages/database/src/api/Database.ts

@@ -41,6 +41,7 @@ import { RepoInfo } from '../core/RepoInfo';
 import { parseRepoInfo } from '../core/util/libs/parser';
 import { newEmptyPath, pathIsEmpty } from '../core/util/Path';
 import {
+  warn,
   fatal,
   log,
   enableLogging as enableLoggingImpl
@@ -276,7 +277,7 @@ export class Database implements _FirebaseService {
 
 function checkTransportInit() {
   if (TransportManager.IS_TRANSPORT_INITIALIZED) {
-    fatal(
+    warn(
       'Transport has already been initialized. Please call this function before calling ref or setting up a listener'
     );
   }

packages/database/test/transport.test.ts

@@ -15,20 +15,30 @@
  * limitations under the License.
  */
 
+
+
 import { CONSTANTS } from '@firebase/util';
-import { expect } from 'chai';
+import { expect, use } from 'chai';
+import { createSandbox, SinonSandbox, SinonSpy } from 'sinon';
+import sinonChai from 'sinon-chai';
 
 import { forceLongPolling, forceWebSockets } from '../src';
+import * as Util from '../src/core/util/util';
 import { BrowserPollConnection } from '../src/realtime/BrowserPollConnection';
 import { TransportManager } from '../src/realtime/TransportManager';
 import { WebSocketConnection } from '../src/realtime/WebSocketConnection';
 
+use(sinonChai);
 const transportInitError =
   'Transport has already been initialized. Please call this function before calling ref or setting up a listener';
 describe('Force Transport', () => {
   const oldNodeValue = CONSTANTS.NODE_CLIENT;
+  let mySandbox: SinonSandbox;
+  let spyWarn: SinonSpy;
   beforeEach(() => {
     CONSTANTS.NODE_CLIENT = false;
+    mySandbox = createSandbox();
+    spyWarn = mySandbox.spy(Util, 'warn');
   });
   afterEach(() => {
     // Resetting to old values
@@ -37,27 +47,32 @@ describe('Force Transport', () => {
     BrowserPollConnection.forceAllow_ = false;
     BrowserPollConnection.forceDisallow_ = true;
     WebSocketConnection.forceDisallow_ = false;
+    mySandbox.restore();
   });
   it('should enable websockets and disable longPolling', () => {
-    expect(forceWebSockets).to.not.throw();
+    forceWebSockets();
+    expect(spyWarn.called).to.equal(false);
     expect(WebSocketConnection.isAvailable()).to.equal(true);
     expect(BrowserPollConnection.isAvailable()).to.equal(false);
   });
   it('should throw an error when calling forceWebsockets() if TransportManager has already been initialized', () => {
     TransportManager.globalTransportInitialized_ = true;
-    expect(forceWebSockets).to.throw(transportInitError);
+    forceWebSockets();
+    expect(spyWarn).to.have.been.calledWith(transportInitError);
     expect(WebSocketConnection.isAvailable()).to.equal(true);
     expect(BrowserPollConnection.isAvailable()).to.equal(false);
   });
   it('should enable longPolling and disable websockets', () => {
-    expect(forceLongPolling).to.not.throw();
+    forceLongPolling();
+    expect(spyWarn.called).to.equal(false);
     expect(WebSocketConnection.isAvailable()).to.equal(false);
     expect(BrowserPollConnection.isAvailable()).to.equal(true);
   });
   it('should throw an error when calling forceLongPolling() if TransportManager has already been initialized', () => {
     TransportManager.globalTransportInitialized_ = true;
-    expect(forceLongPolling).to.throw(transportInitError);
-    expect(WebSocketConnection.isAvailable()).to.equal(true);
-    expect(BrowserPollConnection.isAvailable()).to.equal(false);
+    forceLongPolling();
+    expect(spyWarn).to.have.been.calledWith(transportInitError);
+    expect(WebSocketConnection.isAvailable()).to.equal(false);
+    expect(BrowserPollConnection.isAvailable()).to.equal(true);
   });
 });