Update error message for ERROR_INVALID_HOSTING_LINK_DOMAIN to include that default hosting domains cannot be used.

Author: NhienLam

docs-devsite/auth.actioncodesettings.md

@@ -26,7 +26,7 @@ export interface ActionCodeSettings
 |  [dynamicLinkDomain](./auth.actioncodesettings.md#actioncodesettingsdynamiclinkdomain) | string | When multiple custom dynamic link domains are defined for a project, specify which one to use when the link is to be opened via a specified mobile app (for example, <code>example.page.link</code>). |
 |  [handleCodeInApp](./auth.actioncodesettings.md#actioncodesettingshandlecodeinapp) | boolean | When set to true, the action code link will be be sent as a Universal Link or Android App Link and will be opened by the app if installed. |
 |  [iOS](./auth.actioncodesettings.md#actioncodesettingsios) | { bundleId: string; } | Sets the iOS bundle ID. |
-|  [linkDomain](./auth.actioncodesettings.md#actioncodesettingslinkdomain) | string | The optional custom Firebase Hosting domain to use when the link is to be opened via a specified mobile app. The domain must be configured in Firebase Hosting and owned by the project. This is a replacement of the Dynamic Link. |
+|  [linkDomain](./auth.actioncodesettings.md#actioncodesettingslinkdomain) | string | The optional custom Firebase Hosting domain to use when the link is to be opened via a specified mobile app. The domain must be configured in Firebase Hosting and owned by the project. This cannot be a default hosting domain (web.app or firebaseapp.com). |
 |  [url](./auth.actioncodesettings.md#actioncodesettingsurl) | string | Sets the link continue/state URL. |
 
 ## ActionCodeSettings.android
@@ -85,7 +85,7 @@ iOS?: {
 
 ## ActionCodeSettings.linkDomain
 
-The optional custom Firebase Hosting domain to use when the link is to be opened via a specified mobile app. The domain must be configured in Firebase Hosting and owned by the project. This is a replacement of the Dynamic Link.
+The optional custom Firebase Hosting domain to use when the link is to be opened via a specified mobile app. The domain must be configured in Firebase Hosting and owned by the project. This cannot be a default hosting domain (web.app or firebaseapp.com).
 
 <b>Signature:</b>
 

packages/auth/src/core/errors.ts

@@ -390,7 +390,8 @@ function _debugErrorMap(): ErrorMap<AuthErrorCode> {
     [AuthErrorCode.PASSWORD_DOES_NOT_MEET_REQUIREMENTS]:
       'The password does not meet the requirements.',
     [AuthErrorCode.INVALID_HOSTING_LINK_DOMAIN]:
-      'The provided hosting link domain is not configured in Firebase Hosting or is not owned by the current project.'
+      'The provided hosting link domain is not configured in Firebase Hosting or is not owned by ' +
+      'the current project. This cannot be a default hosting domain (web.app or firebaseapp.com).'
   };
 }
 

packages/auth/src/model/public_types.ts

@@ -518,8 +518,7 @@ export interface ActionCodeSettings {
   /**
    * The optional custom Firebase Hosting domain to use when the link is to be opened via
    * a specified mobile app. The domain must be configured in Firebase Hosting and owned
-   * by the project.
-   * This is a replacement of the Dynamic Link.
+   * by the project. This cannot be a default hosting domain (web.app or firebaseapp.com).
    * @defaultValue The default hosting domain will be used (for example, `example.firebaseapp.com`)
    */
   linkDomain?: string;