Address PR comments

Author: hsubox76

packages/app-check/src/api.test.ts

@@ -121,24 +121,29 @@ describe('api', () => {
       ).to.equal(appCheckInstance);
     });
     it('starts debug mode on first call', async () => {
-      const fakeWrite = (): Promise<void> => Promise.resolve();
-      const writeToIndexedDBStub = stub(
+      let token: string = '';
+      const fakeWrite = (tokenToWrite: string): Promise<void> => {
+        token = tokenToWrite;
+        return Promise.resolve();
+      };
+      stub(
         indexeddb,
         'writeDebugTokenToIndexedDB'
       ).callsFake(fakeWrite);
-      stub(indexeddb, 'readDebugTokenFromIndexedDB').callsFake(() =>
-        Promise.resolve(undefined)
-      );
+      stub(indexeddb, 'readDebugTokenFromIndexedDB').resolves(token);
       const logStub = stub(logger.logger, 'warn');
       const consoleStub = stub(console, 'log');
       self.FIREBASE_APPCHECK_DEBUG_TOKEN = true;
       initializeAppCheck(app, {
         provider: new ReCaptchaV3Provider(FAKE_SITE_KEY)
       });
-      await fakeWrite();
-      const token = writeToIndexedDBStub.args[0];
-      expect(logStub).to.not.be.called;
+      // Ensure getDebugToken() call inside `initializeAppCheck()`
+      // has time to resolve, and double check its value matches that
+      // written to indexedDB.
+      expect(await getDebugToken()).to.equal(token);
       expect(consoleStub.args[0][0]).to.include(token);
+      expect(logStub).to.be.calledWith(match('is in debug mode'));
+      expect(logStub).to.be.calledWith(match(token));
       self.FIREBASE_APPCHECK_DEBUG_TOKEN = undefined;
     });
     it('warns about debug mode on second call', async () => {

packages/app-check/src/api.ts

@@ -23,7 +23,7 @@ import {
   PartialObserver
 } from './public-types';
 import { ERROR_FACTORY, AppCheckError } from './errors';
-import { getState, setState, AppCheckState } from './state';
+import { getState, setState, AppCheckState, getDebugState } from './state';
 import { FirebaseApp, getApp, _getProvider } from '@firebase/app';
 import { getModularInstance, ErrorFn, NextFn } from '@firebase/util';
 import { AppCheckService } from './factory';
@@ -59,6 +59,26 @@ export function initializeAppCheck(
   app = getModularInstance(app);
   const provider = _getProvider(app, 'app-check');
 
+  // Ensure initializeDebugMode() is only called once.
+  if (!getDebugState().initialized) {
+    initializeDebugMode();
+  }
+
+  // Log a warning when `initializeAppCheck()` is called in debug mode,
+  // and show the token.
+  if (isDebugMode()) {
+    logger.warn(
+      `App Check is in debug mode. To turn off debug mode, unset ` +
+        `the global variable FIREBASE_APPCHECK_DEBUG_TOKEN and ` +
+        `restart the app.`
+    );
+    // Make this a separate console statement so user will at least have the
+    // first message if the token promise doesn't resolve in time.
+    void getDebugToken().then(token =>
+      logger.warn(`Debug token is ${token}.`)
+    );
+  }
+
   if (provider.isInitialized()) {
     const existingInstance = provider.getImmediate();
     const initialOptions = provider.getOptions() as unknown as AppCheckOptions;
@@ -67,21 +87,6 @@ export function initializeAppCheck(
         options.isTokenAutoRefreshEnabled &&
       initialOptions.provider.isEqual(options.provider)
     ) {
-      // Log a warning if `initializeAppCheck()` is called after the first time
-      // if this app is still in debug mode, and show the token.
-      // If it's the first time, `initializeDebugMode()` already logs a message.
-      if (isDebugMode()) {
-        logger.warn(
-          `App Check is in debug mode. To turn off debug mode, unset ` +
-            `the global variable FIREBASE_APPCHECK_DEBUG_TOKEN and ` +
-            `restart the app.`
-        );
-        // Make this a separate console statement so user will at least have the
-        // first message if the token promise doesn't resolve in time.
-        void getDebugToken().then(token =>
-          logger.warn(`Debug token is ${token}.`)
-        );
-      }
       return existingInstance;
     } else {
       throw ERROR_FACTORY.create(AppCheckError.ALREADY_INITIALIZED, {
@@ -90,9 +95,6 @@ export function initializeAppCheck(
     }
   }
 
-  // Only read global variable on first call to `initializeAppCheck()`.
-  initializeDebugMode();
-
   const appCheck = provider.initialize({ options });
   _activate(app, options.provider, options.isTokenAutoRefreshEnabled);
 

packages/app-check/src/state.ts

@@ -41,6 +41,7 @@ export interface ReCAPTCHAState {
 }
 
 export interface DebugState {
+  initialized: boolean;
   enabled: boolean;
   token?: Deferred<string>;
 }
@@ -52,6 +53,7 @@ export const DEFAULT_STATE: AppCheckState = {
 };
 
 const DEBUG_STATE: DebugState = {
+  initialized: false,
   enabled: false
 };