Firebase Auth add link domain to actionCodeSetting

src/main/java/com/google/firebase/auth/ActionCodeSettings.java

@@ -51,6 +51,9 @@ private ActionCodeSettings(Builder builder) {
     if (!Strings.isNullOrEmpty(builder.dynamicLinkDomain)) {
       properties.put("dynamicLinkDomain", builder.dynamicLinkDomain);
     }
+    if (!Strings.isNullOrEmpty(builder.linkDomain)) {
+      properties.put("linkDomain", builder.linkDomain);
+    }
     if (!Strings.isNullOrEmpty(builder.iosBundleId)) {
       properties.put("iOSBundleId", builder.iosBundleId);
     }
@@ -83,7 +86,9 @@ public static final class Builder {
 
     private String url;
     private boolean handleCodeInApp;
+    // Deprecated, use linkDomain instead.
     private String dynamicLinkDomain;
+    private String linkDomain;
     private String iosBundleId;
     private String androidPackageName;
     private String androidMinimumVersion;
@@ -135,12 +140,27 @@ public Builder setHandleCodeInApp(boolean handleCodeInApp) {
      *
      * @param dynamicLinkDomain Firebase Dynamic Link domain string.
      * @return This builder.
+     * @deprecated Use {@link #setLinkDomain(String)} instead.
      */
     public Builder setDynamicLinkDomain(String dynamicLinkDomain) {
       this.dynamicLinkDomain = dynamicLinkDomain;
       return this;
     }
 
+    /**
+     * Sets the link domain to use for the current link if it is to be opened using
+     * HandleCodeInApp, as multiple link domains can be configured per project. This
+     * setting provides the ability to explicitly choose one. If none is provided, the default
+     * Firebase Hosting domain will be used.
+     *
+     * @param linkDomain Link domain string.
+     * @return This builder.
+     */
+    public Builder setLinkDomain(String linkDomain) {
+      this.linkDomain = linkDomain;
+      return this;
+    }
+
     /**
      * Sets the bundle ID of the iOS app where the link should be handled if the
      * application is already installed on the device.

src/main/java/com/google/firebase/auth/AuthErrorCode.java

@@ -58,6 +58,11 @@ public enum AuthErrorCode {
    */
   INVALID_DYNAMIC_LINK_DOMAIN,
 
+  /**
+   * The provided hosting link domain is not configured or authorized for the current project.
+   */
+  INVALID_HOSTING_LINK_DOMAIN,
+
   /**
    * The specified ID token is invalid.
    */

src/main/java/com/google/firebase/auth/internal/AuthErrorHandler.java

@@ -73,6 +73,13 @@ final class AuthErrorHandler extends AbstractHttpErrorHandler<FirebaseAuthExcept
                   "The provided dynamic link domain is not "
                       + "configured or authorized for the current project",
                   AuthErrorCode.INVALID_DYNAMIC_LINK_DOMAIN))
+          .put(
+              "INVALID_HOSTING_LINK_DOMAIN",
+              new AuthError(
+                  ErrorCode.INVALID_ARGUMENT,
+                  "The provided hosting link domain is not "
+                      + "configured or authorized for the current project",
+                  AuthErrorCode.INVALID_HOSTING_LINK_DOMAIN))
           .put(
               "PHONE_NUMBER_EXISTS",
               new AuthError(

src/test/java/com/google/firebase/auth/ActionCodeSettingsTest.java

@@ -67,7 +67,7 @@ public void testAllSettings() {
     ActionCodeSettings settings = ActionCodeSettings.builder()
         .setUrl("https://example.com")
         .setHandleCodeInApp(true)
-        .setDynamicLinkDomain("myapp.page.link")
+        .setLinkDomain("myapp.custom.link")
         .setIosBundleId("com.example.ios")
         .setAndroidPackageName("com.example.android")
         .setAndroidMinimumVersion("6.0")
@@ -76,7 +76,7 @@ public void testAllSettings() {
     Map<String, Object> expected = ImmutableMap.<String, Object>builder()
         .put("continueUrl", "https://example.com")
         .put("canHandleCodeInApp", true)
-        .put("dynamicLinkDomain", "myapp.page.link")
+        .put("linkDomain", "myapp.custom.link")
         .put("iOSBundleId", "com.example.ios")
         .put("androidPackageName", "com.example.android")
         .put("androidMinimumVersion", "6.0")