Remove namespace from closure names

src/DevTools/CallbackReflection.php

@@ -110,17 +110,32 @@ public function get_source( $callback ) {
 		if ( $reflection instanceof ReflectionMethod ) {
 			$source['function'] = $reflection->getDeclaringClass()->getName() . '::' . $reflection->getName();
 		} else {
+			$function_name = $reflection->getName();
+
 			/*
 			 * In PHP 8.4, a closure's string representation changes from {closure} to include the function that contained
 			 * the closure, like {closure:Test_AMP_Validation_Manager::test_decorate_shortcode_and_filter_source():1831}.
 			 * It can even indicate closure nesting like {closure:{closure:Test_AMP_Validation_Manager::get_locate_sources_data():883}:886}.
 			 * So these are normalized here.
 			 */
-			$source['function'] = preg_replace(
+			$function_name = preg_replace(
 				'/\{closure.*}/',
 				'{closure}',
-				$reflection->getName()
+				$function_name
+			);
+
+			/*
+			 * Additionally, in PHP 8.4 the namespace no longer prefixes the closure. So this is now removed
+			 * for consistency across all PHP versions, replacing AmpProject\AmpWP\Tests\DevTools\{closure}
+			 * with just {closure}.
+			 */
+			$function_name = preg_replace(
+				'/(\w+\\\\)+(?=\{)/',
+				'',
+				$function_name
 			);
+
+			$source['function'] = $function_name;
 		}
 
 		return $source;

tests/php/src/DevTools/CallbackReflectionTest.php

@@ -208,7 +208,7 @@ public function data_get_source() {
 			],
 			'plugin_closure'                      => [
 				function () {},
-				__NAMESPACE__ . '\{closure}',
+				'{closure}',
 				'amp',
 				'plugin',
 				'tests/php/src/DevTools/CallbackReflectionTest.php',
@@ -246,7 +246,6 @@ public function test_get_source( $function, $source_function, $name, $type, $fil
 		/** @var ReflectionFunction $reflection */
 		$reflection = $source['reflection'];
 		$this->assertInstanceOf( $reflection_class, $reflection );
-		$this->assertEquals( preg_replace( '/.*::/', '', $source['function'] ), $reflection->getName() );
 	}
 
 	/**