diff --git a/packages/auth/src/auth.js b/packages/auth/src/auth.js
index 2a2c18d6e05..fa498d6c038 100644
--- a/packages/auth/src/auth.js
+++ b/packages/auth/src/auth.js
@@ -294,30 +294,57 @@ fireauth.Auth.prototype.useDeviceLanguage = function() {
 
 /**
  * Sets the emulator configuration (go/firebase-emulator-connection-api).
-  /**
-   * Sets the emulator configuration (go/firebase-emulator-connection-api).
-   * @param {string} url The url for the Auth emulator.
-   */
+ * @param {string} url The url for the Auth emulator.
+ */
 fireauth.Auth.prototype.useEmulator = function(url) {
-  // Don't do anything if no change detected.
-  if (!this.emulatorConfig_ || url !== this.emulatorConfig_.url) {
-    console.warn("WARNING: You are using the Auth Emulator, which is" +
-      " intended for local testing only.  Do not use with" +
-      " production credentials.");
-    this.emulatorConfig_ = { url: url };
+  // Emulator config can only be set once.
+  if (!this.emulatorConfig_) {
+    // Emit a warning so dev knows we are now in test mode.
+    this.emitEmulatorWarning_();
+    // Persist the config.
+    this.emulatorConfig_ = { url };
     // Disable app verification.
-    this.settings_().setAppVerificationDisabledForTesting(true);
-    // Update custom Firebase locale field.
+    this.settings.setAppVerificationDisabledForTesting(true);
+    // Update RPC handler endpoints.
     this.rpcHandler_.updateEmulatorConfig(this.emulatorConfig_);
-    // Notify external language code change listeners.
+    // Notify external event listeners.
     this.notifyEmulatorConfigListeners_();
   }
 }
 
+
+/**
+ * Emits a console warning and a visual banner if emulator integration is
+ * enabled.
+ */
+fireauth.Auth.prototype.emitEmulatorWarning_ = function() {
+  fireauth.util.consoleWarn('WARNING: You are using the Auth Emulator,' +
+    ' which is intended for local testing only.  Do not use with' +
+    ' production credentials.');
+  if (goog.global.document) {
+    const ele = goog.global.document.createElement('p');
+    ele.innerText = 'Running in emulator mode. Do not use with production' +
+      ' credentials.';
+    ele.style.position = 'fixed';
+    ele.style.width = '100%';
+    ele.style.backgroundColor = '#ffffff';
+    ele.style.border = '.1em solid #000000';
+    ele.style.color = '#ff0000';
+    ele.style.bottom = '0px';
+    ele.style.left = '0px';
+    ele.style.margin = '0px';
+    ele.style.zIndex = 10000;
+    ele.style.textAlign = 'center';
+    ele.classList.add('firebase-emulator-warning');
+    goog.global.document.body.appendChild(ele);
+  }
+}
+
+
 /**
  * @return {?fireauth.constants.EmulatorSettings}
  */
-fireauth.Auth.prototype.getEmulatorConfig = function () {
+fireauth.Auth.prototype.getEmulatorConfig = function() {
   return this.emulatorConfig_;
 }
 
@@ -451,7 +478,7 @@ fireauth.Auth.prototype.notifyLanguageCodeListeners_ = function() {
  * @private
  */
 fireauth.Auth.prototype.notifyEmulatorConfigListeners_ = function() {
-  // Notify external listeners on the language code change.
+  // Notify external listeners on the emulator config change.
   this.dispatchEvent(
     new fireauth.Auth.EmulatorConfigChangeEvent(this.emulatorConfig_));
 }
@@ -877,7 +904,6 @@ fireauth.Auth.prototype.updateCurrentUser = function(user) {
   options['apiKey'] = this.app_().options['apiKey'];
   options['authDomain'] = this.app_().options['authDomain'];
   options['appName'] = this.app_().name;
-  options['emulatorConfig'] = this.emulatorConfig_;
   var newUser = fireauth.AuthUser.copyUser(user, options,
       self.redirectUserStorageManager_, self.getFramework());
   return this.registerPendingPromise_(
@@ -922,7 +948,9 @@ fireauth.Auth.prototype.signInWithIdTokenResponse =
   options['apiKey'] = self.app_().options['apiKey'];
   options['authDomain'] = self.app_().options['authDomain'];
   options['appName'] = self.app_().name;
-  options['emulatorConfig'] = self.emulatorConfig_;
+  if (self.emulatorConfig_) {
+      options['emulatorConfig'] = self.emulatorConfig_;
+  }
   // Wait for state to be ready.
   // This is used internally and is also used for redirect sign in so there is
   // no need for waiting for redirect result to resolve since redirect result
@@ -1071,7 +1099,7 @@ fireauth.Auth.prototype.initAuthState_ = function() {
   var p = this.initRedirectUser_().then(function() {
     // Override user's authDomain with app's authDomain if there is a mismatch.
     return /** @type {!fireauth.storage.UserManager} */ (
-        self.userStorageManager_).getCurrentUser(authDomain);
+      self.userStorageManager_).getCurrentUser(authDomain, self.emulatorConfig_);
   }).then(function(user) {
     // Logged in user.
     if (user) {
@@ -1765,17 +1793,6 @@ fireauth.Auth.prototype.app_ = function() {
 };
 
 
-
-/**
- * @return {!fireauth.AuthSettings} The AuthSettings object this auth object
- *   is connected to.
- * @private
- */
-fireauth.Auth.prototype.settings_ = function() {
-  return this['settings'];
-}
-
-
 /**
  * @return {!fireauth.RpcHandler} The RPC handler.
  */
diff --git a/packages/auth/src/autheventmanager.js b/packages/auth/src/autheventmanager.js
index 9e5ca22bf0b..a6bb62df6af 100644
--- a/packages/auth/src/autheventmanager.js
+++ b/packages/auth/src/autheventmanager.js
@@ -672,12 +672,18 @@ fireauth.AuthEventManager.KEY_SEPARATOR_ = ':';
 /**
  * @param {string} apiKey The API key for sending backend Auth requests.
  * @param {string} appName The Auth instance that initiated the Auth event.
- * @return {string} The key identifying the Auth event manager instance.
- * @private
- */
-fireauth.AuthEventManager.getKey_ = function(apiKey, appName) {
-  return apiKey + fireauth.AuthEventManager.KEY_SEPARATOR_ + appName;
-};
+   * @param {?fireauth.constants.EmulatorSettings=} emulatorConfig The emulator
+   *   configuration.
+   * @return {string} The key identifying the Auth event manager instance.
+   * @private
+   */
+fireauth.AuthEventManager.getKey_ = function(apiKey, appName, emulatorConfig) {
+  var key = apiKey + fireauth.AuthEventManager.KEY_SEPARATOR_ + appName;
+  if (emulatorConfig) {
+    key = key + fireauth.AuthEventManager.KEY_SEPARATOR_ + emulatorConfig.url;
+  }
+  return key;
+}
 
 
 /**
@@ -690,18 +696,26 @@ fireauth.AuthEventManager.getKey_ = function(apiKey, appName) {
  *     configuration.
  * @return {!fireauth.AuthEventManager} the requested manager instance.
  */
-fireauth.AuthEventManager.getManager = function(authDomain, apiKey, appName, emulatorConfig) {
+fireauth.AuthEventManager.getManager = function (authDomain, apiKey, appName, emulatorConfig) {
   // Construct storage key.
-  var key = fireauth.AuthEventManager.getKey_(apiKey, appName);
+  var key = fireauth.AuthEventManager.getKey_(
+    apiKey,
+    appName,
+    emulatorConfig
+  );
   if (!fireauth.AuthEventManager.manager_[key]) {
     fireauth.AuthEventManager.manager_[key] =
-        new fireauth.AuthEventManager(authDomain, apiKey, appName, emulatorConfig);
+      new fireauth.AuthEventManager(
+        authDomain,
+        apiKey,
+        appName,
+        emulatorConfig
+      );
   }
   return fireauth.AuthEventManager.manager_[key];
 };
 
 
-
 /**
  * The interface that represents a specific type of Auth event processor.
  * @interface
diff --git a/packages/auth/src/authuser.js b/packages/auth/src/authuser.js
index ac57962941e..bedde8dc345 100644
--- a/packages/auth/src/authuser.js
+++ b/packages/auth/src/authuser.js
@@ -351,10 +351,10 @@ fireauth.AuthUser.prototype.setLanguageCodeChangeDispatcher =
 
 
 /**
-* Listens to emulator config changes triggered by the provided dispatcher.
-* @param {?goog.events.EventTarget} dispatcher The emulator config changed
-*     event dispatcher.
-*/
+  * Listens to emulator config changes triggered by the provided dispatcher.
+  * @param {?goog.events.EventTarget} dispatcher The emulator config changed
+  *     event dispatcher.
+  */
 fireauth.AuthUser.prototype.setEmulatorConfigChangeDispatcher = function(dispatcher) {
   // Remove any previous listener.
   if (this.emulatorConfigChangeEventDispatcher_) {
@@ -367,7 +367,7 @@ fireauth.AuthUser.prototype.setEmulatorConfigChangeDispatcher = function(dispatc
   this.emulatorConfigChangeEventDispatcher_ = dispatcher;
   // Using an event listener makes it easy for non-currentUsers to detect
   // emulator changes on the parent Auth instance. A developer could still
-  // call APIs that require localization on signed out user references.
+  // call APIs that require emulation on signed out user references.
   if (dispatcher) {
     goog.events.listen(
       dispatcher, fireauth.constants.AuthEventType.EMULATOR_CONFIG_CHANGED,
@@ -2423,7 +2423,8 @@ fireauth.AuthUser.fromPlainObject = function(user) {
   var options = {
     'apiKey': user['apiKey'],
     'authDomain': user['authDomain'],
-    'appName': user['appName']
+    'appName': user['appName'],
+    'emulatorConfig': user['emulatorConfig']
   };
   // Convert to server response format. Constructor does not take
   // stsTokenManager toPlainObject as that format is different than the return
diff --git a/packages/auth/src/cordovahandler.js b/packages/auth/src/cordovahandler.js
index d379829b003..6646d2da821 100644
--- a/packages/auth/src/cordovahandler.js
+++ b/packages/auth/src/cordovahandler.js
@@ -56,18 +56,17 @@ goog.require('goog.crypt.Sha256');
  * @param {string} authDomain The application authDomain.
  * @param {string} apiKey The API key.
  * @param {string} appName The App name.
- * @param {?string=} opt_clientVersion The optional client version string.
- * @param {number=} opt_initialTimeout Initial Auth event timeout.
- * @param {number=} opt_redirectTimeout Redirect result timeout.
- * @param {?string=} opt_endpointId The endpoint ID (staging, test Gaia, etc).
+ * @param {?string=} clientVersion The optional client version string.
+ * @param {number=} initialTimeout Initial Auth event timeout.
+ * @param {number=} redirectTimeout Redirect result timeout.
+ * @param {?string=} endpointId The endpoint ID (staging, test Gaia, etc).
  * @param {?fireauth.constants.EmulatorSettings=} emulatorConfig The emulator
  *     configuration
  * @constructor
  * @implements {fireauth.OAuthSignInHandler}
  */
 fireauth.CordovaHandler = function(authDomain, apiKey, appName,
-    opt_clientVersion, opt_initialTimeout, opt_redirectTimeout,
-    opt_endpointId, emulatorConfig) {
+    clientVersion, initialTimeout, redirectTimeout, endpointId, emulatorConfig) {
   /** @private {string} The application authDomain. */
   this.authDomain_ = authDomain;
   /** @private {string} The application API key. */
@@ -75,9 +74,9 @@ fireauth.CordovaHandler = function(authDomain, apiKey, appName,
   /** @private {string} The application name. */
   this.appName_ = appName;
   /** @private {?string} The client version */
-  this.clientVersion_ = opt_clientVersion || null;
+  this.clientVersion_ = clientVersion || null;
   /** @private {?string} The Auth endpoint ID. */
-  this.endpointId_ = opt_endpointId || null;
+  this.endpointId_ = endpointId || null;
   /**
    * @private @const {?fireauth.constants.EmulatorSettings|undefined}
    * The emulator configuration
@@ -109,10 +108,10 @@ fireauth.CordovaHandler = function(authDomain, apiKey, appName,
    */
   this.authEventListeners_ = [];
   /** @private {number} The initial Auth event timeout. */
-  this.initialTimeout_ = opt_initialTimeout ||
+  this.initialTimeout_ = initialTimeout ||
       fireauth.CordovaHandler.INITIAL_TIMEOUT_MS_;
   /** @private {number} The return to app after redirect timeout. */
-  this.redirectTimeout_ = opt_redirectTimeout ||
+  this.redirectTimeout_ = redirectTimeout ||
       fireauth.CordovaHandler.REDIRECT_TIMEOUT_MS_;
   /**
    * @private {?goog.Promise} The last pending redirect promise. This is null if
diff --git a/packages/auth/src/iframeclient/ifchandler.js b/packages/auth/src/iframeclient/ifchandler.js
index 39d32e143a1..9bf7a29a4e5 100644
--- a/packages/auth/src/iframeclient/ifchandler.js
+++ b/packages/auth/src/iframeclient/ifchandler.js
@@ -104,8 +104,8 @@ fireauth.iframeclient.IframeUrlBuilder = function(authDomain, apiKey, appName, e
       null);
   }
   /**
-  * @private @const {!goog.Uri} The URI object used to build the iframe URL.
-  */
+   * @private @const {!goog.Uri} The URI object used to build the iframe URL.
+   */
   this.uri_ = uri;
   this.uri_.setParameterValue('apiKey', this.apiKey_);
   this.uri_.setParameterValue('appName', this.appName_);
@@ -774,6 +774,9 @@ fireauth.iframeclient.IfcHandler.prototype.getRpcHandler_ = function() {
         // Get the client Auth endpoint used.
         fireauth.constants.getEndpointConfig(this.endpointId_),
         this.fullClientVersion_);
+    if (this.emulatorConfig_) {
+        this.rpcHandler_.updateEmulatorConfig(this.emulatorConfig_);
+    }
   }
   return this.rpcHandler_;
 };
diff --git a/packages/auth/src/rpchandler.js b/packages/auth/src/rpchandler.js
index 0b6147682ce..df1e287f9ce 100644
--- a/packages/auth/src/rpchandler.js
+++ b/packages/auth/src/rpchandler.js
@@ -437,10 +437,10 @@ fireauth.RpcHandler.prototype.updateCustomLocaleHeader =
 
 
 /**
-* Updates the emulator configuration.
-* @param {?fireauth.constants.EmulatorSettings} emulatorConfig The new
-*     emulator config.
-*/
+ * Updates the emulator configuration.
+ * @param {?fireauth.constants.EmulatorSettings} emulatorConfig The new
+ *     emulator config.
+ */
 fireauth.RpcHandler.prototype.updateEmulatorConfig = function(emulatorConfig) {
   if (!emulatorConfig) {
     return;
@@ -457,24 +457,21 @@ fireauth.RpcHandler.prototype.updateEmulatorConfig = function(emulatorConfig) {
       fireauth.RpcHandler.IDENTITY_PLATFORM_ENDPOINT_, emulatorConfig);
 }
 
-
-/**
- * Creates an endpoint URL intended for use by the emulator.
- *
- * According to go/firebase-auth-emulator-dd
- * @param {string} endpoint the production endpoint URL.
- * @param {?fireauth.constants.EmulatorSettings} emulatorConfig The emulator
- *     config.
- * @return {string} The emulator endpoint URL.
- * @private
- */
+  /**
+   * Creates an endpoint URL intended for use by the emulator.
+   * @param {string} endpoint the production endpoint URL.
+   * @param {?fireauth.constants.EmulatorSettings} emulatorConfig The emulator
+   *     config.
+   * @return {string} The emulator endpoint URL.
+   * @private
+   */
 fireauth.RpcHandler.generateEmululatorEndpointUrl_ = function(endpoint, emulatorConfig) {
   const uri = goog.Uri.parse(endpoint);
-  const endpointUri = goog.Uri.parse(emulatorConfig.url);
+  const emulatorUri = goog.Uri.parse(emulatorConfig.url);
   uri.setPath(uri.getDomain() + uri.getPath());
-  uri.setScheme(endpointUri.getScheme());
-  uri.setDomain(endpointUri.getDomain());
-  uri.setPort(endpointUri.getPort());
+  uri.setScheme(emulatorUri.getScheme());
+  uri.setDomain(emulatorUri.getDomain());
+  uri.setPort(emulatorUri.getPort());
   return uri.toString();
 }
 
diff --git a/packages/auth/src/storageusermanager.js b/packages/auth/src/storageusermanager.js
index 816664f1f6d..c3d3b28d1eb 100644
--- a/packages/auth/src/storageusermanager.js
+++ b/packages/auth/src/storageusermanager.js
@@ -67,6 +67,7 @@ goog.provide('fireauth.storage.UserManager');
 
 goog.require('fireauth.AuthUser');
 goog.require('fireauth.authStorage');
+goog.require('fireauth.constants');
 goog.require('goog.Promise');
 
 
@@ -399,13 +400,14 @@ fireauth.storage.UserManager.prototype.removeCurrentUser = function() {
 
 
 /**
- * @param {?string=} opt_authDomain The optional Auth domain to override if
+ * @param {?string=} authDomain The optional Auth domain to override if
  *     provided.
+ * @param {?fireauth.constants.EmulatorSettings=} emulatorConfig The current
+ *     emulator config to use in user requests.
  * @return {!goog.Promise<?fireauth.AuthUser>} A promise that resolves with
  *     the stored current user for the provided app ID.
  */
-fireauth.storage.UserManager.prototype.getCurrentUser =
-    function(opt_authDomain) {
+fireauth.storage.UserManager.prototype.getCurrentUser = function(authDomain, emulatorConfig) {
   var self = this;
   // Wait for any pending persistence change to be resolved.
   return this.waitForReady_(function() {
@@ -420,8 +422,11 @@ fireauth.storage.UserManager.prototype.getCurrentUser =
           // authDomain for the purpose of linking with a popup. The loaded user
           // (stored without the authDomain) must have this field updated with
           // the current authDomain.
-          if (response && opt_authDomain) {
-            response['authDomain'] = opt_authDomain;
+          if (response && authDomain) {
+            response['authDomain'] = authDomain;
+          }
+          if (response && emulatorConfig) {
+            response['emulatorConfig'] = emulatorConfig;
           }
           return fireauth.AuthUser.fromPlainObject(response || {});
         });
diff --git a/packages/auth/test/auth_test.js b/packages/auth/test/auth_test.js
index e0264f34df5..c1876a95e37 100644
--- a/packages/auth/test/auth_test.js
+++ b/packages/auth/test/auth_test.js
@@ -449,6 +449,12 @@ function tearDown() {
   fireauth.authStorage.Manager.clear();
   currentUserStorageManager = null;
   redirectUserStorageManager = null;
+  if (goog.global.document) {
+    var el = goog.global.document.querySelector('.firebase-emulator-warning');
+    if (el) {
+      el.parentNode.removeChild(el);
+    }
+  }
 }
 
 
@@ -904,8 +910,16 @@ function testUseEmulator() {
     fireauth.RpcHandler.prototype,
     'updateEmulatorConfig',
     goog.testing.recordFunction());
+  stubs.replace(
+    fireauth.util,
+    'consoleWarn',
+    goog.testing.recordFunction());
   var handler = goog.testing.recordFunction();
-
+  stubs.replace(
+    fireauth.AuthSettings.prototype,
+    'setAppVerificationDisabledForTesting',
+    goog.testing.recordFunction());
+  
   app1 = firebase.initializeApp(config1, appId1);
   auth1 = app1.auth();
 
@@ -919,46 +933,57 @@ function testUseEmulator() {
   assertEquals(0, handler.getCallCount());
   assertEquals(
     0, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
+  assertEquals(0, fireauth.util.consoleWarn.getCallCount());
+  assertEquals(
+    0,
+    fireauth.AuthSettings.prototype.setAppVerificationDisabledForTesting.
+      getCallCount());
 
   // Update the emulator config.
   auth1.useEmulator('http://emulator.test.domain:1234');
   assertObjectEquals(
-    auth1.getEmulatorConfig(), {
-    url: 'http://emulator.test.domain:1234',
-  });
+    {
+      url: 'http://emulator.test.domain:1234',
+    },
+    auth1.getEmulatorConfig());
   // Should notify the RPC handler.
   assertEquals(
     1, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
-  assertObjectEquals({
-    url: 'http://emulator.test.domain:1234',
-  },
+  assertObjectEquals(
+    {
+      url: 'http://emulator.test.domain:1234',
+    },
     fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
       .getArgument(0)
   );
+  // Should emit a console warning.
+  assertEquals(1, fireauth.util.consoleWarn.getCallCount());
+  // Should disable App verification.
+  assertEquals(
+    true,
+    fireauth.AuthSettings.prototype.setAppVerificationDisabledForTesting.
+      getLastCall().getArgument(0));
 
   // Update to the same config should not trigger event again.
   auth1.useEmulator('http://emulator.test.domain:1234');
   assertObjectEquals(
-    auth1.getEmulatorConfig(), {
-    url: 'http://emulator.test.domain:1234',
-  });
+    {
+      url: 'http://emulator.test.domain:1234',
+    },
+    auth1.getEmulatorConfig());
   assertEquals(
     1, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
+  assertEquals(1, fireauth.util.consoleWarn.getCallCount());
 
-  // Updating to different config should trigger event.
+  // Updating to different config should still not trigger event.
   auth1.useEmulator('http://emulator.other.domain:9876');
   assertObjectEquals(
-    auth1.getEmulatorConfig(), {
-    url: 'http://emulator.other.domain:9876'
-  });
+    {
+      url: 'http://emulator.test.domain:1234',
+    },
+    auth1.getEmulatorConfig());
   assertEquals(
-    2, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
-  assertObjectEquals({
-    url: 'http://emulator.other.domain:9876',
-  },
-    fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
-      .getArgument(0)
-  );
+    1, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
 }
 
 
@@ -2275,6 +2300,60 @@ function testAuth_authEventManager_withEmulator() {
 }
 
 
+/** Asserts that AuthEventManager can pass through emulator settings. */
+function testAuth_authEventManager_withEmulator() {
+  // Test Auth event manager.
+  fireauth.AuthEventManager.ENABLED = true;
+  stubs.reset();
+  initializeMockStorage();
+  var expectedManager = {
+    'subscribe': goog.testing.recordFunction(),
+    'unsubscribe': goog.testing.recordFunction(),
+    'clearRedirectResult': goog.testing.recordFunction()
+  };
+  // Return stub manager.
+  stubs.replace(
+    fireauth.AuthEventManager,
+    'getManager',
+    function (authDomain, apiKey, appName, emulatorConfig) {
+      assertEquals('subdomain.firebaseapp.com', authDomain);
+      assertEquals('API_KEY', apiKey);
+      assertEquals(appId1, appName);
+      assertObjectEquals(emulatorConfig, {
+        url: 'http://emulator.host:1234'
+      });
+      return expectedManager;
+    });
+  asyncTestCase.waitForSignals(1);
+  app1 = firebase.initializeApp(config3, appId1);
+  auth1 = app1.auth();
+  auth1.useEmulator('http://emulator.host:1234');
+  // Test manager initialized and Auth subscribed.
+  auth1.onIdTokenChanged(function (user) {
+    var manager = fireauth.AuthEventManager.getManager(
+      config3['authDomain'], config3['apiKey'], app1.name, {
+      url: 'http://emulator.host:1234'
+    });
+    assertEquals(expectedManager, manager);
+    assertEquals(0, expectedManager.unsubscribe.getCallCount());
+    assertEquals(1, expectedManager.subscribe.getCallCount());
+    assertEquals(
+      auth1, expectedManager.subscribe.getLastCall().getArgument(0));
+    assertEquals(0, expectedManager.clearRedirectResult.getCallCount());
+    // Delete should trigger unsubscribe and redirect result clearing.
+    auth1.delete();
+    // After destroy, Auth should be unsubscribed.
+    assertEquals(1, expectedManager.subscribe.getCallCount());
+    assertEquals(1, expectedManager.unsubscribe.getCallCount());
+    // Redirect result should also be cleared.
+    assertEquals(1, expectedManager.clearRedirectResult.getCallCount());
+    assertEquals(
+      auth1, expectedManager.unsubscribe.getLastCall().getArgument(0));
+    asyncTestCase.signal();
+  });
+}
+
+
 function testAuth_signout() {
   // Test successful sign out.
   fireauth.AuthEventManager.ENABLED = true;
@@ -2463,6 +2542,71 @@ function testAuth_initState_signedInStatus() {
 }
 
 
+function testAuth_initState_signedInStatus_withEmulator() {
+  // Test init state with previously signed in user.
+  fireauth.AuthEventManager.ENABLED = true;
+  stubs.reset();
+  // Simulate current origin is whitelisted.
+  simulateWhitelistedOrigin();
+  stubs.replace(
+    goog,
+    'now',
+    function () {
+      return now;
+    });
+  initializeMockStorage();
+  // Stub OAuth sign in handler.
+  fakeOAuthSignInHandler();
+  // New loaded user should be reloaded before being set as current user.
+  stubs.replace(
+    fireauth.AuthUser.prototype,
+    'reload',
+    function () {
+      // Access token unchanged, should trigger notifyAuthListeners_.
+      return goog.Promise.resolve();
+    });
+  // Listen to calls on RPC Handler.
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'updateEmulatorConfig',
+    goog.testing.recordFunction(
+      fireauth.RpcHandler.prototype.updateEmulatorConfig));
+  asyncTestCase.waitForSignals(1);
+  // Logged in user to be detected in initState.
+  var user1 = new fireauth.AuthUser(
+    config3, expectedTokenResponse, accountInfo);
+  // Save signed in user to storage.
+  currentUserStorageManager = new fireauth.storage.UserManager(
+    config3['apiKey'] + ':' + appId1);
+  currentUserStorageManager.setCurrentUser(user1).then(function () {
+    app1 = firebase.initializeApp(config3, appId1);
+    auth1 = app1.auth();
+    // Set emulator.
+    auth1.useEmulator('http://emulator.test.domain:1234');
+    // Before init state current user is null.
+    assertNull(auth1['currentUser']);
+    // User state change triggered with user.
+    auth1.onAuthStateChanged(function (user) {
+      // Signed in user should be detected.
+      assertUserEquals(user1, auth1['currentUser']);
+      // Emulator config should propagate to currentUser.
+      assertEquals(
+        3, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
+      assertEquals(auth1['currentUser'].getRpcHandler(),
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+          .getThis());
+      assertObjectEquals(
+        {
+          url: 'http://emulator.test.domain:1234'
+        },
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+          .getArgument(0));
+      asyncTestCase.signal();
+    });
+  });
+}
+
+
 /**
  * Test that external changes on a saved user will apply after loading from
  * storage and reload on user is called. Confirm the updated user is saved.
@@ -4280,6 +4424,57 @@ function testAuth_signInWithIdTokenResponse_newUserDifferentFromCurrent() {
 }
 
 
+/**
+ * Asserts that a new signed in user gets emulator configuration set correctly.
+ */
+function testAuth_signInWithIdTokenResponse_withEmulator() {
+  // Test signInWithIdTokenResponse returning a new user.
+  fireauth.AuthEventManager.ENABLED = true;
+  stubs.reset();
+  // Simulate current origin is whitelisted.
+  simulateWhitelistedOrigin();
+  stubs.replace(
+    goog,
+    'now',
+    function () {
+      return now;
+    });
+  initializeMockStorage();
+  // Stub OAuth sign in handler.
+  fakeOAuthSignInHandler();
+  // Initialize from ID token response should be called and resolved with the
+  // new signed in user.
+  stubs.replace(
+    fireauth.AuthUser,
+    'initializeFromIdTokenResponse',
+    function (options, idTokenResponse) {
+      // Confirm emulatorConfig set on user's app options.
+      assertObjectEquals(expectedOptions, options);
+      return goog.Promise.resolve(user1);
+    });
+  asyncTestCase.waitForSignals(1);
+  var expectedOptions = Object.assign({}, config3);
+  expectedOptions['emulatorConfig'] = {
+    url: 'http://emulator.test.domain:1234',
+  };
+  // The newly signed in user.
+  var user1 = new fireauth.AuthUser(
+    config3, expectedTokenResponse, accountInfo);
+
+  app1 = firebase.initializeApp(config3, appId1);
+  auth1 = app1.auth();
+  // Set emulator.
+  auth1.useEmulator('http://emulator.test.domain:1234');
+  // User not logged in yet. Run sign in with ID token response.
+  // The user should be initialized with the emulator config.
+  auth1.signInWithIdTokenResponse(expectedTokenResponse).then(function () {
+    // Current user should be set to user1.
+    assertEquals(user1, auth1['currentUser']);
+    asyncTestCase.signal();
+  });
+}
+
+
 function testAuth_getIdToken_signedInUser() {
   // Tests getIdToken with a signed in user.
   fireauth.AuthEventManager.ENABLED = true;
diff --git a/packages/auth/test/autheventmanager_test.js b/packages/auth/test/autheventmanager_test.js
index e36d39dd56b..3613aa3a2cd 100644
--- a/packages/auth/test/autheventmanager_test.js
+++ b/packages/auth/test/autheventmanager_test.js
@@ -272,6 +272,19 @@ function testGetManager() {
   assertEquals(
       fireauth.AuthEventManager.getManager(authDomain2, apiKey2, appName2),
       manager2);
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  var managerWithEmulator = fireauth.AuthEventManager.getManager(
+      authDomain1, apiKey1, appName1, emulatorConfig);
+  assertEquals(
+      fireauth.AuthEventManager.manager_[
+      fireauth.AuthEventManager.getKey_(apiKey1, appName1)],
+      manager1);
+  assertEquals(
+      fireauth.AuthEventManager.manager_[
+      fireauth.AuthEventManager.getKey_(apiKey1, appName1, emulatorConfig)],
+      managerWithEmulator);
 }
 
 
@@ -286,7 +299,7 @@ function testInstantiateOAuthSignInHandler_ifcHandler() {
   // Confirm expected endpoint used.
   ifcHandlerConstructor(
       authDomain1, apiKey1, appName1, firebase.SDK_VERSION,
-      fireauth.constants.Endpoint.STAGING.id).$returns(ifcHandler);
+      fireauth.constants.Endpoint.STAGING.id, ignoreArgument).$returns(ifcHandler);
   mockControl.$replayAll();
 
   fireauth.AuthEventManager.instantiateOAuthSignInHandler(
@@ -295,6 +308,31 @@ function testInstantiateOAuthSignInHandler_ifcHandler() {
 }
 
 
+/** Asserts that emulator config is propagated to ifcHandler. */
+function testInstantiateOAuthSignInHandler_ifcHandler_withEmulator() {
+  // Simulate browser environment.
+  setOAuthSignInHandlerEnvironment(false);
+  // IfcHandler should be instantiated.
+  var ifcHandler = mockControl.createStrictMock(
+    fireauth.iframeclient.IfcHandler);
+  var ifcHandlerConstructor = mockControl.createConstructorMock(
+    fireauth.iframeclient, 'IfcHandler');
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  // Confirm expected endpoint used.
+  ifcHandlerConstructor(
+    authDomain1, apiKey1, appName1, firebase.SDK_VERSION,
+    fireauth.constants.Endpoint.STAGING.id,
+    emulatorConfig).$returns(ifcHandler);
+  mockControl.$replayAll();
+
+  fireauth.AuthEventManager.instantiateOAuthSignInHandler(
+    authDomain1, apiKey1, appName1, firebase.SDK_VERSION,
+    fireauth.constants.Endpoint.STAGING.id, emulatorConfig);
+}
+
+
 function testInstantiateOAuthSignInHandler_cordovaHandler() {
   // Simulate Cordova environment
   setOAuthSignInHandlerEnvironment(true);
@@ -306,7 +344,7 @@ function testInstantiateOAuthSignInHandler_cordovaHandler() {
   // Confirm expected endpoint used.
   cordovaHandlerConstructor(
       authDomain1, apiKey1, appName1, firebase.SDK_VERSION, undefined,
-      undefined, fireauth.constants.Endpoint.STAGING.id)
+      undefined, fireauth.constants.Endpoint.STAGING.id, ignoreArgument)
       .$returns(cordovaHandler);
   mockControl.$replayAll();
 
@@ -316,6 +354,30 @@ function testInstantiateOAuthSignInHandler_cordovaHandler() {
 }
 
 
+/** Asserts that emulator config is propagated to cordovaHandler. */
+function testInstantiateOAuthSignInHandler_cordovaHandler_withEmulator() {
+  // Simulate Cordova environment
+  setOAuthSignInHandlerEnvironment(true);
+  // CordovaHandler should be instantiated.
+  var cordovaHandler = mockControl.createStrictMock(
+    fireauth.CordovaHandler);
+  var cordovaHandlerConstructor = mockControl.createConstructorMock(
+    fireauth, 'CordovaHandler');
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  // Confirm expected endpoint used.
+  cordovaHandlerConstructor(
+    authDomain1, apiKey1, appName1, firebase.SDK_VERSION, undefined,
+    undefined, fireauth.constants.Endpoint.STAGING.id, emulatorConfig)
+    .$returns(cordovaHandler);
+  mockControl.$replayAll();
+
+  fireauth.AuthEventManager.instantiateOAuthSignInHandler(
+    authDomain1, apiKey1, appName1, firebase.SDK_VERSION,
+    fireauth.constants.Endpoint.STAGING.id, emulatorConfig);
+}
+
 
 function testAuthEventManager_initialize_manually_withSubscriber() {
   var expectedAuthEvent = new fireauth.AuthEvent(
@@ -396,6 +458,48 @@ function testAuthEventManager_initialize_manually_withNoSubscriber() {
 }
 
 
+function testAuthEventManager_initialize_manually_withEmulator() {
+  var expectedEmulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  var expectedAuthEvent = new fireauth.AuthEvent(
+    'linkViaPopup', '1234', 'http://www.example.com/#response', 'SESSION_ID');
+  var isReady = false;
+  // This test is not environment specific.
+  stubs.replace(
+    fireauth.AuthEventManager,
+    'instantiateOAuthSignInHandler',
+    function (authDomain, apiKey, appName, version, endpoint, emulatorConfig) {
+      assertEquals('subdomain1.firebaseapp.com', authDomain);
+      assertEquals('API_KEY1', apiKey);
+      assertEquals('APP1', appName);
+      assertEquals(firebase.SDK_VERSION, version);
+      assertUndefined(endpoint);
+      assertObjectEquals(emulatorConfig, expectedEmulatorConfig);
+      isReady = true;
+      return {
+        'addAuthEventListener': function (handler) {
+          handler(expectedAuthEvent);
+        },
+        'initializeAndWait': function () { return goog.Promise.resolve(); },
+        'shouldBeInitializedEarly': function () {
+          return false;
+        },
+        'hasVolatileStorage': function () {
+          return false;
+        }
+      };
+    });
+  asyncTestCase.waitForSignals(1);
+  var manager = fireauth.AuthEventManager.getManager(
+    authDomain1, apiKey1, appName1, expectedEmulatorConfig);
+  manager.initialize().then(function () {
+    assertTrue(isReady);
+    asyncTestCase.signal();
+  });
+}
+
+
 function testAuthEventManager_initialize_automatically_pendingRedirect() {
   // Test automatic initialization when pending redirect available on
   // subscription.
diff --git a/packages/auth/test/authuser_test.js b/packages/auth/test/authuser_test.js
index f72e9a01f43..33c4dbc0064 100644
--- a/packages/auth/test/authuser_test.js
+++ b/packages/auth/test/authuser_test.js
@@ -718,6 +718,41 @@ function testUser() {
 }
 
 
+/**
+ * Asserts that a user initiated with an emulator config will propagate
+ * the config to the RPC handler.
+ */
+function tesUser_initWithEmulator() {
+  // Listen to emulator config calls on RpcHandler.
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'updateEmulatorConfig',
+    goog.testing.recordFunction());
+
+  // Initialize a user.
+  user = new fireauth.AuthUser(
+    {
+      appName: config1.appName,
+      apiKey: config1.apiKey,
+      emulatorConfig: {
+        url: 'http://emulator.test.domain:1234'
+      }
+    }
+  );
+
+  // Should notify the RPC handler.
+  assertEquals(
+    1, fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
+  assertObjectEquals(
+    {
+      url: 'http://emulator.test.domain:1234',
+    },
+    fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+      .getArgument(0)
+  );
+}
+
+
 function testUser_multiFactor() {
   user = new fireauth.AuthUser(
       config1, tokenResponse, accountInfoWithEnrolledFactors);
@@ -768,7 +803,7 @@ function testUser_copyUser() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -2156,7 +2191,7 @@ function testUser_getIdToken_expiredToken_reauthWithPopupAfterInvalidation() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -2469,7 +2504,7 @@ function testUser_getIdToken_expiredToken_reauthWithPopupBeforeInvalidation() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -4404,7 +4439,7 @@ function testDestroy() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   mockControl.$replayAll();
   // Confirm a user is subscribed to Auth event manager.
   stubs.replace(
@@ -5793,7 +5828,7 @@ function testUser_linkWithRedirect_success_unloadsOnRedirect() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -5881,7 +5916,7 @@ function testUser_reauthenticateWithRedirect_success_unloadsOnRedirect() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -5963,7 +5998,7 @@ function testUser_linkWithRedirect_success_unloadsOnRedirect_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6061,7 +6096,7 @@ function testUser_reauthWithRedirect_success_unloadsOnRedirect_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6146,7 +6181,7 @@ function testUser_linkWithRedirect_success_doesNotUnloadOnRedirect() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6230,7 +6265,7 @@ function testUser_reauthenticateWithRedirect_success_doesNotUnloadOnRedirect() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6307,7 +6342,7 @@ function testUser_linkWithRedirect_success_doesNotUnloadOnRedirect_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6400,7 +6435,7 @@ function testUser_reauthWithRedirect_success_doesNotUnload_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6479,7 +6514,7 @@ function testUser_linkWithRedirect_success_noStorageManager() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6561,7 +6596,7 @@ function testUser_reauthenticateWithRedirect_success_noStorageManager() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6704,7 +6739,7 @@ function testUser_linkWithRedirect_invalidProvider() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processRedirect(
@@ -6828,7 +6863,7 @@ function testUser_linkWithPopup_success_slowIframeEmbed() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -6983,7 +7018,7 @@ function testUser_reauthenticateWithPopup_success_slowIframeEmbed() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -7136,7 +7171,7 @@ function testUser_linkWithPopup_error_popupClosed() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -7269,7 +7304,7 @@ function testUser_reauthenticateWithPopup_error_popupClosed() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -7390,7 +7425,7 @@ function testUser_linkWithPopup_error_iframeWebStorageNotSupported() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -7516,7 +7551,7 @@ function testUser_reauthWithPopup_error_iframeWebStorageNotSupported() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -7635,7 +7670,7 @@ function testUser_linkWithPopup_success_withoutPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -7784,7 +7819,7 @@ function testUser_linkWithPopup_success_withPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -7939,7 +7974,7 @@ function testUser_linkWithPopup_success_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -8098,7 +8133,7 @@ function testUser_reauthenticateWithPopup_success_withoutPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -8251,7 +8286,7 @@ function testUser_reauthenticateWithPopup_success_withPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -8407,7 +8442,7 @@ function testUser_linkWithPopup_emailCredentialError() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -8549,7 +8584,7 @@ function testUser_reauthenticateWithPopup_userMismatchError() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -8776,7 +8811,7 @@ function testUser_linkWithPopup_success_cannotRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -8957,7 +8992,7 @@ function testUser_linkWithPopup_success_cannotRunInBackground_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -9151,7 +9186,7 @@ function testUser_reauthenticateWithPopup_success_cannotRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -9322,7 +9357,7 @@ function testUser_reauthenticateWithPopup_success_cannotRunInBkg_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -9506,7 +9541,7 @@ function testUser_linkWithPopup_success_iframeCanRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -9699,7 +9734,7 @@ function testUser_reauthenticateWithPopup_success_iframeCanRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -9880,7 +9915,7 @@ function testUser_linkWithPopup_webStorageUnsupported_cannotRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -10037,7 +10072,7 @@ function testUser_reauthWithPopup_webStorageUnsupported_cantRunInBackground() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -10188,7 +10223,7 @@ function testUser_linkWithPopup_multipleUsers_success() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
@@ -10406,7 +10441,7 @@ function testUser_reauthenticateWithPopup_multipleUsers_success() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -10615,7 +10650,7 @@ function testUser_linkWithPopup_timeout() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -10802,7 +10837,7 @@ function testUser_reauthenticateWithPopup_timeout() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -10979,7 +11014,7 @@ function testUser_linkWithPopup_error() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.shouldBeInitializedEarly().$returns(false);
   oAuthSignInHandlerInstance.hasVolatileStorage().$returns(false);
   oAuthSignInHandlerInstance.processPopup(
@@ -11112,7 +11147,7 @@ function testUser_reauthenticateWithPopup_error() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -11261,7 +11296,7 @@ function testUser_returnFromLinkWithRedirect_success_withoutPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11336,7 +11371,7 @@ function testUser_returnFromLinkWithRedirect_success_withPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11414,7 +11449,7 @@ function testUser_returnFromLinkWithRedirect_success_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11493,7 +11528,7 @@ function testUser_returnFromReauthenticateWithRedirect_success_noPostBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11568,7 +11603,7 @@ function testUser_returnFromReauthenticateWithRedirect_success_postBody() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11646,7 +11681,7 @@ function testUser_returnFromReauthenticateWithRedirect_success_tenantId() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11725,7 +11760,7 @@ function testUser_returnFromLinkWithRedirect_success_multipleUsers() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Both users should be subscribed.
@@ -11818,7 +11853,7 @@ function testUser_returnFromReauthenticateWithRedirect_success_multipleUsers() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Both users should be subscribed.
@@ -11907,7 +11942,7 @@ function testUser_returnFromLinkWithRedirect_invalidUser() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -11969,7 +12004,7 @@ function testUser_returnFromReauthenticateWithRedirect_invalidUser() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -12032,7 +12067,7 @@ function testUser_returnFromLinkWithRedirect_error() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -12096,7 +12131,7 @@ function testUser_returnFromReauthenticateWithRedirect_error() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -13173,7 +13208,7 @@ function testUser_customLocaleChanges() {
 
 
 function testUser_emulatorConfigChanges() {
-  // Listen to all custom locale header calls on RpcHandler.
+  // Listen to all custom emulator config change calls on RpcHandler.
   stubs.replace(
     fireauth.RpcHandler.prototype,
     'updateEmulatorConfig',
@@ -13203,7 +13238,7 @@ function testUser_emulatorConfigChanges() {
       .getArgument(0)
   );
 
-  // Set dispatcher1 as language code dispatcher.
+  // Set dispatcher1 as emulator config change dispatcher.
   user.setEmulatorConfigChangeDispatcher(dispatcher1);
   dispatcher1.dispatchEvent(
     new fireauth.Auth.EmulatorConfigChangeEvent(emulatorConfig));
@@ -13941,7 +13976,7 @@ function testReauthenticateWithPopup_multiFactor_success() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -14170,7 +14205,7 @@ function testReauthenticateWithPopup_multiFactor_mismatchError() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.processPopup(
       ignoreArgument,
       ignoreArgument,
@@ -14322,7 +14357,7 @@ function testReturnFromReauthenticateWithRedirect_multiFactor_success() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
@@ -14479,7 +14514,7 @@ function testReturnFromReauthenticateWithRedirect_multiFactor_mismatchError() {
       fireauth.AuthEventManager, 'instantiateOAuthSignInHandler');
   instantiateOAuthSignInHandler(
       ignoreArgument, ignoreArgument, ignoreArgument, ignoreArgument,
-      ignoreArgument).$returns(oAuthSignInHandlerInstance);
+      ignoreArgument, ignoreArgument).$returns(oAuthSignInHandlerInstance);
   oAuthSignInHandlerInstance.addAuthEventListener(ignoreArgument)
       .$does(function(handler) {
         // Dispatch expected Auth event immediately to simulate return from
diff --git a/packages/auth/test/cordovahandler_test.js b/packages/auth/test/cordovahandler_test.js
index c21d35293c7..e002d434c4c 100644
--- a/packages/auth/test/cordovahandler_test.js
+++ b/packages/auth/test/cordovahandler_test.js
@@ -1248,6 +1248,103 @@ function testCordovaHandler_processRedirect_success_parallelCalls_tenantId() {
 }
 
 
+function testCordovaHandler_processRedirect_success_withEmulator() {
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  return installAndRunTest(
+    'testCordovaHandler_processRedirect_success_withEmulator',
+    function () {
+      var provider = new fireauth.GoogleAuthProvider();
+      // Construct OAuth handler URL.
+      var expectedUrl =
+        fireauth.iframeclient.IfcHandler.getOAuthHelperWidgetUrl(
+          authDomain,
+          apiKey,
+          appName,
+          'linkViaRedirect',
+          provider,
+          null,
+          '1234',
+          version,
+          {
+            apn: 'com.example.app',
+            appDisplayName: 'Test App',
+            sessionId: sha256('11111111111111111111')
+          },
+          // Confirm expected endpoint ID passed.
+          fireauth.constants.Endpoint.STAGING.id,
+          null,
+          emulatorConfig);
+      // Stub this so the session ID generated can be predictable.
+      stubs.replace(
+        Math,
+        'random',
+        function () {
+          return 0;
+        });
+      // Simulate Android environment.
+      stubs.replace(
+        fireauth.util,
+        'getUserAgentString',
+        function () {
+          return androidUA;
+        });
+      var incomingUrl =
+        'http://emulator.test.domain:1234/__/auth/callback#oauthResponse';
+      // Completed event.
+      var completeEvent = new fireauth.AuthEvent(
+        'linkViaRedirect',
+        '1234',
+        incomingUrl,
+        '11111111111111111111');
+      // Initial unknown event.
+      var noEvent = new fireauth.AuthEvent(
+        fireauth.AuthEvent.Type.UNKNOWN,
+        null,
+        null,
+        null,
+        new fireauth.AuthError(fireauth.authenum.Error.NO_AUTH_EVENT));
+      var savedCb = null;
+      // Save the universal link callback on subscription.
+      universalLinks.subscribe = function (eventType, cb) {
+        savedCb = cb;
+      };
+      cordova.plugins.browsertab.openUrl = function (url) {
+        // Confirm expected URL.
+        assertEquals(expectedUrl, url);
+        // On openUrl, simulate completion by triggering the universal link
+        // callback with the OAuth response.
+        savedCb({ url: incomingUrl });
+      };
+      var handler = goog.testing.recordFunction();
+      cordovaHandler = new fireauth.CordovaHandler(
+        authDomain, apiKey, appName, version, 10, undefined,
+        fireauth.constants.Endpoint.STAGING.id, emulatorConfig);
+      cordovaHandler.addAuthEventListener(handler);
+      return cordovaHandler.processRedirect('linkViaRedirect', provider, '1234')
+        .then(function () {
+          // Confirm browsertab close called.
+          assertEquals(1, cordova.plugins.browsertab.close.getCallCount());
+          // Handler triggered twice.
+          assertEquals(2, handler.getCallCount());
+          // First with no event.
+          assertAuthEventEquals(
+            noEvent,
+            handler.getCalls()[0].getArgument(0));
+          // Then with resolved event.
+          assertAuthEventEquals(
+            completeEvent,
+            handler.getLastCall().getArgument(0));
+          // Confirm event deleted from storage.
+          return getAndDeletePartialEventManager.getAuthEvent();
+        }).then(function (event) {
+          assertNull(event);
+        });
+    });
+}
+
+
 function testCordovaHandler_processRedirect_success_ios() {
   return installAndRunTest('processRedirect_success_ios', function() {
     var provider = new fireauth.GoogleAuthProvider();
diff --git a/packages/auth/test/iframeclient/ifchandler_test.js b/packages/auth/test/iframeclient/ifchandler_test.js
index 5b669d4b3bc..1e8ff964368 100644
--- a/packages/auth/test/iframeclient/ifchandler_test.js
+++ b/packages/auth/test/iframeclient/ifchandler_test.js
@@ -205,6 +205,21 @@ function testIframeUrlBuilder() {
 }
 
 
+/**
+ * Asserts IframeUrlBuilder.prototype.toString handles emulator URLs.
+ */
+function testIframeUrlBuilder_withEmulator() {
+  var builder = new fireauth.iframeclient.IframeUrlBuilder(
+    'example.firebaseapp.com', 'API_KEY', 'MY_APP', {
+    url: 'http://emulator.test.domain:1234'
+  });
+  assertEquals(
+    'http://emulator.test.domain:1234/emulator/auth/iframe?' +
+    'apiKey=API_KEY&appName=MY_APP',
+    builder.setVersion(null).toString());
+}
+
+
 function testOAuthUrlBuilder() {
   var redirectUrl = 'http://www.example.com/redirect?a=b#c';
   var redirectUrl2 = 'http://www.example.com/redirect2?d=e#f';
@@ -605,6 +620,25 @@ function testIfcHandler() {
 }
 
 
+/**
+ * Asserts getIframeUrl handles emulator URLs.
+ */
+function testIfcHandler_withEmulator() {
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  // The expected iframe URL.
+  var expectedUrl = fireauth.iframeclient.IfcHandler.getAuthIframeUrl(
+    authDomain, apiKey, appName, version, undefined, undefined,
+    emulatorConfig);
+  // Initialize the ifcHandler.
+  ifcHandler = new fireauth.iframeclient.IfcHandler(
+    authDomain, apiKey, appName, version, undefined, emulatorConfig);
+  // Confirm expected iframe URL.
+  assertEquals(ifcHandler.getIframeUrl(), expectedUrl);
+}
+
+
 function testIfcHandler_shouldNotBeInitializedEarly() {
   ifcHandler = new fireauth.iframeclient.IfcHandler(
       authDomain, apiKey, appName, version);
@@ -708,7 +742,7 @@ function testIfcHandler_initializeAndWait_success() {
       fireauth.iframeclient, 'IframeWrapper');
   // Iframe initialized with expected endpoint ID.
   getAuthIframeUrl(authDomain, apiKey, appName, ignoreArgument,
-      fireauth.constants.Endpoint.STAGING.id, expectedFrameworks)
+      fireauth.constants.Endpoint.STAGING.id, expectedFrameworks, ignoreArgument)
       .$returns('https://url');
   // Confirm iframe URL returned by getAuthIframeUrl used to initialize the
   // IframeWrapper.
@@ -935,7 +969,7 @@ function testIfcHandler_processPopup_notAlreadyRedirected_success() {
 }
 
 
-function testIfcHandler_processPopup_notAlreadyRedirected_tenentId_success() {
+function testIfcHandler_processPopup_notAlreadyRedirected_tenantId_success() {
   asyncTestCase.waitForSignals(1);
   var popupWin = {
     close: goog.testing.recordFunction()
@@ -993,6 +1027,77 @@ function testIfcHandler_processPopup_notAlreadyRedirected_tenentId_success() {
 }
 
 
+/** Asserts processRedirect can handle emulator URLs. */
+function testIfcHandler_processPopup_success_withEmulator() {
+  var emulatorConfig = {
+    url: 'http:/emulator.test.domain:1234'
+  };
+  asyncTestCase.waitForSignals(1);
+  var popupWin = {
+    close: goog.testing.recordFunction()
+  };
+  var onInit = goog.testing.recordFunction();
+  var onError = goog.testing.recordFunction();
+  stubs.replace(
+    fireauth.util,
+    'goTo',
+    goog.testing.recordFunction());
+  // Assume origin is a valid one.
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'getAuthorizedDomains',
+    function () {
+      var uri = goog.Uri.parse(fireauth.util.getCurrentUrl());
+      var domain = uri.getDomain();
+      return goog.Promise.resolve([domain]);
+    });
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'updateEmulatorConfig',
+    goog.testing.recordFunction());
+  var provider = new fireauth.GoogleAuthProvider();
+  var expectedUrl = fireauth.iframeclient.IfcHandler.getOAuthHelperWidgetUrl(
+    authDomain,
+    apiKey,
+    appName,
+    'linkViaPopup',
+    provider,
+    null,
+    '1234',
+    version,
+    undefined,
+    // Check expected endpoint ID appended.
+    fireauth.constants.Endpoint.STAGING.id,
+    undefined,
+    emulatorConfig);
+  ifcHandler = new fireauth.iframeclient.IfcHandler(
+    authDomain, apiKey, appName, version,
+    fireauth.constants.Endpoint.STAGING.id, emulatorConfig);
+  // Should succeed.
+  ifcHandler.processPopup(
+    popupWin, 'linkViaPopup', provider, onInit, onError, '1234', false)
+    .then(function () {
+      // On init should be called as the iframe is initialized.
+      assertEquals(1, onInit.getCallCount());
+      // No error.
+      assertEquals(0, onError.getCallCount());
+      // Popup redirected.
+      assertEquals(
+        expectedUrl,
+        fireauth.util.goTo.getLastCall().getArgument(0));
+      // Emulator config set on RpcHandler.
+      assertObjectEquals(
+        emulatorConfig,
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+          .getArgument(0));
+      assertEquals(
+        popupWin,
+        fireauth.util.goTo.getLastCall().getArgument(1));
+      asyncTestCase.signal();
+    });
+}
+
+
 function testIfcHandler_processPopup_redirected_iframeCanRunInBG_success() {
   asyncTestCase.waitForSignals(1);
   // Simulate that the app can run in the background but is running in an
@@ -1485,6 +1590,64 @@ function testIfcHandler_processRedirect_networkError_then_success() {
 }
 
 
+/** Asserts that processRedirects works with emulator URLs. */
+function testIfcHandler_processRedirect_success_withEmulator() {
+  var emulatorConfig = {
+    url: 'http:/emulator.test.domain:1234'
+  };
+  var provider = new fireauth.GoogleAuthProvider();
+  var expectedUrl = fireauth.iframeclient.IfcHandler.getOAuthHelperWidgetUrl(
+    authDomain,
+    apiKey,
+    appName,
+    'linkViaRedirect',
+    provider,
+    fireauth.util.getCurrentUrl(),
+    '1234',
+    version,
+    undefined,
+    // Check expected endpoint ID appended.
+    fireauth.constants.Endpoint.STAGING.id,
+    null,
+    emulatorConfig);
+  asyncTestCase.waitForSignals(1);
+  // Assume origin is a valid one.
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'getAuthorizedDomains',
+    function () {
+      var uri = goog.Uri.parse(fireauth.util.getCurrentUrl());
+      var domain = uri.getDomain();
+      return goog.Promise.resolve([domain]);
+    });
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'updateEmulatorConfig',
+    goog.testing.recordFunction());
+  stubs.replace(
+    fireauth.util,
+    'goTo',
+    goog.testing.recordFunction());
+  ifcHandler = new fireauth.iframeclient.IfcHandler(
+    authDomain, apiKey, appName, version,
+    fireauth.constants.Endpoint.STAGING.id, emulatorConfig);
+  // Should succeed and redirect.
+  ifcHandler.processRedirect('linkViaRedirect', provider, '1234')
+    .then(function () {
+      /** @suppress {missingRequire} */
+      assertEquals(
+        expectedUrl,
+        fireauth.util.goTo.getLastCall().getArgument(0));
+      // Emulator config set on RpcHandler.
+      assertObjectEquals(
+        emulatorConfig,
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+          .getArgument(0));
+      asyncTestCase.signal();
+    });
+}
+
+
 /**
  * Tests getAuthIframeUrl.
  */
@@ -1503,7 +1666,7 @@ function testGetAuthIframeUrl() {
 
 
 /**
- * Tests getAuthIframeUrl with emulator.
+ * Asserts getAuthIframeUrl handles emulator URLs.
  */
 function testGetAuthIframeUrl_withEmulator() {
   var authDomain = 'subdomain.firebaseapp.com';
@@ -1841,3 +2004,39 @@ function testGetOAuthHelperWidgetUrl_frameworksAndLanguageCode() {
           authDomain, apiKey, appName, authType, provider));
 }
 
+
+/**
+ * Asserts getOAuthHelperWidgetUrl handles emulator URLs.
+ */
+function testGetOAuthHelperWidgetUrl_withEmulator() {
+  var authDomain = 'subdomain.firebaseapp.com';
+  var apiKey = 'apiKey1';
+  var appName = 'appName1';
+  var authType = 'signInWithPopup';
+  var providerId = 'facebook.com';
+  var provider = new fireauth.FacebookAuthProvider();
+  var emulatorConfig = {
+    url: 'http://emulator.test.domain:1234'
+  };
+  var expectedWidgetUrl = 'http://emulator.test.domain:1234/' +
+    'emulator/auth/handler' +
+    '?apiKey=' + encodeURIComponent(apiKey) +
+    '&appName=' + encodeURIComponent(appName) +
+    '&authType=' + encodeURIComponent(authType) +
+    '&providerId=' + encodeURIComponent(providerId);
+  assertEquals(
+    expectedWidgetUrl,
+    fireauth.iframeclient.IfcHandler.getOAuthHelperWidgetUrl(
+      authDomain,
+      apiKey,
+      appName,
+      authType,
+      provider,
+      null,
+      null,
+      null,
+      null,
+      null,
+      null,
+      emulatorConfig));
+}
\ No newline at end of file
diff --git a/packages/auth/test/rpchandler_test.js b/packages/auth/test/rpchandler_test.js
index a23a4a59ff2..916ded8a37f 100644
--- a/packages/auth/test/rpchandler_test.js
+++ b/packages/auth/test/rpchandler_test.js
@@ -1194,7 +1194,7 @@ function testRequestStsToken_emulator() {
   // Set an emulator config.
   rpcHandler.updateEmulatorConfig(
     { url: 'http://emulator.test.domain:1234' });
-  // Send STS token request, default config will be used.
+  // Send STS token request, emulator config will be used.
   rpcHandler
     .requestStsToken({ 'grant_type': 'authorization_code', 'code': 'idToken' })
     .then(function (response) {
diff --git a/packages/auth/test/storageusermanager_test.js b/packages/auth/test/storageusermanager_test.js
index 7acc451a509..991755b8d83 100644
--- a/packages/auth/test/storageusermanager_test.js
+++ b/packages/auth/test/storageusermanager_test.js
@@ -190,7 +190,13 @@ function testGetSetRemoveCurrentUser() {
   expectedUser = new fireauth.AuthUser(config, tokenResponse, accountInfo);
   // Expected user with authDomain.
   expectedUserWithAuthDomain =
-      new fireauth.AuthUser(configWithAuthDomain, tokenResponse, accountInfo);
+    new fireauth.AuthUser(configWithAuthDomain, tokenResponse, accountInfo);
+  // Listen to calls on RPC Handler.
+  stubs.replace(
+    fireauth.RpcHandler.prototype,
+    'updateEmulatorConfig',
+    goog.testing.recordFunction(
+      fireauth.RpcHandler.prototype.updateEmulatorConfig));
   var storageKey = 'firebase:authUser:appId1';
   return goog.Promise.resolve()
       .then(function() {
@@ -210,7 +216,23 @@ function testGetSetRemoveCurrentUser() {
       })
       .then(function(user) {
         fireauth.common.testHelper.assertUserEquals(
-            expectedUserWithAuthDomain, user);
+          expectedUserWithAuthDomain, user);
+        // Get user with authDomain & emulator config.
+        return userManager.getCurrentUser('project.firebaseapp.com',
+          {
+            url: 'http://emulator.test.domain:1234'
+          });
+      })
+    .then(function () {
+      // Verify RpcHandler was notified of config change.
+      assertEquals(1,
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getCallCount());
+      assertObjectEquals(
+        {
+          url: 'http://emulator.test.domain:1234'
+        },
+        fireauth.RpcHandler.prototype.updateEmulatorConfig.getLastCall()
+          .getArgument(0));
         return userManager.removeCurrentUser();
       })
       .then(function() {