Fix child theme activation failure on subsequent runs with different slug and name

features/scaffold.feature

@@ -58,6 +58,44 @@ Feature: WordPress code scaffolding
       Success: Network enabled the 'Zombieland' theme.
       """
 
+  Scenario: Scaffold a child theme and activate it with different slug and name
+    Given a WP install
+
+    When I run `wp theme install twentytwentyone --force`
+    Then STDOUT should not be empty
+
+    And I run `wp theme path`
+    And save STDOUT as {THEME_DIR}
+
+    When I run `wp scaffold child-theme first-run --parent_theme=twentytwentyone --theme_name="First Run Name" --activate`
+    Then STDOUT should contain:
+      """
+      Success: Created '{THEME_DIR}/first-run'.
+      """
+    And STDOUT should contain:
+      """
+      Success: Switched to 'First Run Name' theme.
+      """
+
+    When I run `wp theme list --fields=name,status --format=csv`
+    Then STDOUT should contain:
+      """
+      first-run,active
+      """
+
+    # Now delete the theme and create it again to test the fix for the caching issue
+    When I run `rm -rf {THEME_DIR}/first-run`
+    And I run `wp theme activate twentytwentyone`
+    And I run `wp scaffold child-theme first-run --parent_theme=twentytwentyone --theme_name="First Run Name" --activate`
+    Then STDOUT should contain:
+      """
+      Success: Created '{THEME_DIR}/first-run'.
+      """
+    And STDOUT should contain:
+      """
+      Success: Switched to 'First Run Name' theme.
+      """
+
   Scenario: Scaffold a child theme with invalid slug
     Given a WP install
     When I try `wp scaffold child-theme . --parent_theme=simple-life`

src/Scaffold_Command.php

@@ -539,12 +539,28 @@ public function child_theme( $args, $assoc_args ) {
 		$this->log_whether_files_written( $files_written, $skip_message, $success_message );
 
 		if ( Utils\get_flag_value( $assoc_args, 'activate' ) ) {
+			$this->refresh_theme_cache();
 			WP_CLI::run_command( [ 'theme', 'activate', $theme_slug ] );
 		} elseif ( Utils\get_flag_value( $assoc_args, 'enable-network' ) ) {
+			$this->refresh_theme_cache();
 			WP_CLI::run_command( [ 'theme', 'enable', $theme_slug ], [ 'network' => true ] );
 		}
 	}
 
+	/**
+	 * Refreshes WordPress theme cache.
+	 *
+	 * Clears PHP's filesystem cache, WordPress theme_roots transient, object cache,
+	 * and rebuilds the theme directory cache. This ensures newly created themes are
+	 * recognized by WordPress before attempting to activate or enable them.
+	 */
+	private function refresh_theme_cache() {
+		clearstatcache();
+		delete_site_transient( 'theme_roots' );
+		wp_cache_delete( 'themes', 'themes' );
+		search_theme_directories( true );
+	}
+
 	private function get_output_path( $assoc_args, $subdir ) {
 		if ( $assoc_args['theme'] ) {
 			$theme = $assoc_args['theme'];