minor #48793 Leverage arrow function syntax for closure (tigitz)

This PR was merged into the 6.3 branch.

Discussion
----------

Leverage arrow function syntax for closure

| Q             | A
| ------------- | ---
| Branch?       | 6.3
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | Fix #47658 <!-- prefix each issue number with "Fix #", no need to create an issue if none exists, explain below instead -->
| License       | MIT
| Doc PR        | <!-- required for new features -->

Rationale in the RFC [here](https://wiki.php.net/rfc/arrow_functions_v2#introduction)

It's also notable that using arrow function syntax rather than the classic one has been enforced in the past by symfony core member: symfony/symfony#48069 (comment)

So this PR would be consistent.

Commits
-------

f5802d3a2a Leverage arrow function syntax for closure

Author: nicolas-grekas

Generator/UrlGenerator.php

@@ -269,9 +269,7 @@ protected function doGenerate(array $variables, array $defaults, array $requirem
         }
 
         // add a query string if needed
-        $extra = array_udiff_assoc(array_diff_key($parameters, $variables), $defaults, function ($a, $b) {
-            return $a == $b ? 0 : 1;
-        });
+        $extra = array_udiff_assoc(array_diff_key($parameters, $variables), $defaults, fn ($a, $b) => $a == $b ? 0 : 1);
 
         array_walk_recursive($extra, $caster = static function (&$v) use (&$caster) {
             if (\is_object($v)) {

Loader/AnnotationDirectoryLoader.php

@@ -36,15 +36,11 @@ public function load(mixed $path, string $type = null): ?RouteCollection
         $files = iterator_to_array(new \RecursiveIteratorIterator(
             new \RecursiveCallbackFilterIterator(
                 new \RecursiveDirectoryIterator($dir, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS),
-                function (\SplFileInfo $current) {
-                    return !str_starts_with($current->getBasename(), '.');
-                }
+                fn (\SplFileInfo $current) => !str_starts_with($current->getBasename(), '.')
             ),
             \RecursiveIteratorIterator::LEAVES_ONLY
         ));
-        usort($files, function (\SplFileInfo $a, \SplFileInfo $b) {
-            return (string) $a > (string) $b ? 1 : -1;
-        });
+        usort($files, fn (\SplFileInfo $a, \SplFileInfo $b) => (string) $a > (string) $b ? 1 : -1);
 
         foreach ($files as $file) {
             if (!$file->isFile() || !str_ends_with($file->getFilename(), '.php')) {

Loader/Psr4DirectoryLoader.php

@@ -66,15 +66,11 @@ private function loadFromDirectory(string $directory, string $psr4Prefix): Route
         $files = iterator_to_array(new \RecursiveIteratorIterator(
             new \RecursiveCallbackFilterIterator(
                 new \RecursiveDirectoryIterator($directory, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS),
-                function (\SplFileInfo $current) {
-                    return !str_starts_with($current->getBasename(), '.');
-                }
+                fn (\SplFileInfo $current) => !str_starts_with($current->getBasename(), '.')
             ),
             \RecursiveIteratorIterator::SELF_FIRST
         ));
-        usort($files, function (\SplFileInfo $a, \SplFileInfo $b) {
-            return (string) $a > (string) $b ? 1 : -1;
-        });
+        usort($files, fn (\SplFileInfo $a, \SplFileInfo $b) => (string) $a > (string) $b ? 1 : -1);
 
         /** @var \SplFileInfo $file */
         foreach ($files as $file) {

Matcher/ExpressionLanguageProvider.php

@@ -36,12 +36,8 @@ public function getFunctions(): array
         foreach ($this->functions->getProvidedServices() as $function => $type) {
             $functions[] = new ExpressionFunction(
                 $function,
-                static function (...$args) use ($function) {
-                    return sprintf('($context->getParameter(\'_functions\')->get(%s)(%s))', var_export($function, true), implode(', ', $args));
-                },
-                function ($values, ...$args) use ($function) {
-                    return $values['context']->getParameter('_functions')->get($function)(...$args);
-                }
+                static fn (...$args) => sprintf('($context->getParameter(\'_functions\')->get(%s)(%s))', var_export($function, true), implode(', ', $args)),
+                fn ($values, ...$args) => $values['context']->getParameter('_functions')->get($function)(...$args)
             );
         }
 

RouteCollection.php

@@ -103,9 +103,7 @@ public function all(): array
         if ($this->priorities) {
             $priorities = $this->priorities;
             $keysOrder = array_flip(array_keys($this->routes));
-            uksort($this->routes, static function ($n1, $n2) use ($priorities, $keysOrder) {
-                return (($priorities[$n2] ?? 0) <=> ($priorities[$n1] ?? 0)) ?: ($keysOrder[$n1] <=> $keysOrder[$n2]);
-            });
+            uksort($this->routes, static fn ($n1, $n2) => (($priorities[$n2] ?? 0) <=> ($priorities[$n1] ?? 0)) ?: ($keysOrder[$n1] <=> $keysOrder[$n2]));
         }
 
         return $this->routes;

Tests/Fixtures/CustomXmlFileLoader.php

@@ -21,6 +21,6 @@ class CustomXmlFileLoader extends XmlFileLoader
 {
     protected function loadFile(string $file): \DOMDocument
     {
-        return XmlUtils::loadFile($file, function () { return true; });
+        return XmlUtils::loadFile($file, fn () => true);
     }
 }

Tests/Fixtures/glob/php_dsl.php

@@ -2,6 +2,4 @@
 
 namespace Symfony\Component\Routing\Loader\Configurator;
 
-return function (RoutingConfigurator $routes) {
-    return $routes->import('php_dsl_ba?.php');
-};
+return fn (RoutingConfigurator $routes) => $routes->import('php_dsl_ba?.php');

Tests/Loader/AnnotationDirectoryLoaderTest.php

@@ -112,8 +112,6 @@ private function expectAnnotationsToBeReadFrom(array $classes)
     {
         $this->reader->expects($this->exactly(\count($classes)))
             ->method('getClassAnnotation')
-            ->with($this->callback(function (\ReflectionClass $class) use ($classes) {
-                return \in_array($class->getName(), $classes);
-            }));
+            ->with($this->callback(fn (\ReflectionClass $class) => \in_array($class->getName(), $classes)));
     }
 }

Tests/Matcher/ExpressionLanguageProviderTest.php

@@ -25,23 +25,12 @@ class ExpressionLanguageProviderTest extends TestCase
     protected function setUp(): void
     {
         $functionProvider = new ServiceLocator([
-            'env' => function () {
-                // function with one arg
-                return function (string $arg) {
-                    return [
-                        'APP_ENV' => 'test',
-                        'PHP_VERSION' => '7.2',
-                    ][$arg] ?? null;
-                };
-            },
-            'sum' => function () {
-                // function with multiple args
-                return function ($a, $b) { return $a + $b; };
-            },
-            'foo' => function () {
-                // function with no arg
-                return function () { return 'bar'; };
-            },
+            'env' => fn () => fn (string $arg) => [
+                'APP_ENV' => 'test',
+                'PHP_VERSION' => '7.2',
+            ][$arg] ?? null,
+            'sum' => fn () => fn ($a, $b) => $a + $b,
+            'foo' => fn () => fn () => 'bar',
         ]);
 
         $this->context = new RequestContext();

Tests/RouteTest.php

@@ -98,7 +98,7 @@ public function testDefaults()
         $this->assertEquals('bar2', $route->getDefault('foo2'), '->getDefault() return the default value');
         $this->assertNull($route->getDefault('not_defined'), '->getDefault() return null if default value is not set');
 
-        $route->setDefault('_controller', $closure = function () { return 'Hello'; });
+        $route->setDefault('_controller', $closure = fn () => 'Hello');
         $this->assertEquals($closure, $route->getDefault('_controller'), '->setDefault() sets a default value');
 
         $route->setDefaults(['foo' => 'foo']);