Address review feedback: bump version constant, use instanceof WP_User checks

- Update TWO_FACTOR_VERSION fallback define to 0.16.0 to match the plugin header
- Replace truthiness checks with `instanceof WP_User` in Two_Factor_Email
  authentication_page(), pre_process_authentication() and validate_authentication()

Author: aslamdoctor

providers/class-two-factor-email.php

@@ -340,7 +340,7 @@ public function generate_and_email_token( $user ) {
 	 * @param WP_User|false $user WP_User object of the logged-in user.
 	 */
 	public function authentication_page( $user ) {
-		if ( ! $user ) {
+		if ( ! ( $user instanceof WP_User ) ) {
 			return;
 		}
 
@@ -388,7 +388,7 @@ public function authentication_page( $user ) {
 	 * @return boolean
 	 */
 	public function pre_process_authentication( $user ) {
-		if ( ! $user ) {
+		if ( ! ( $user instanceof WP_User ) ) {
 			return false;
 		}
 
@@ -409,7 +409,7 @@ public function pre_process_authentication( $user ) {
 	 * @return boolean
 	 */
 	public function validate_authentication( $user ) {
-		if ( ! $user ) {
+		if ( ! ( $user instanceof WP_User ) ) {
 			return false;
 		}
 

two-factor.php

@@ -27,7 +27,7 @@
 }
 
 if ( ! defined( 'TWO_FACTOR_VERSION' ) ) {
-	define( 'TWO_FACTOR_VERSION', '0.15.0' );
+	define( 'TWO_FACTOR_VERSION', '0.16.0' );
 }
 
 if ( ! defined( 'ABSPATH' ) ) {