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

Command/DebugCommand.php

@@ -162,9 +162,7 @@ private function displayPathsText(SymfonyStyle $io, string $name)
                 [$namespace, $shortname] = $this->parseTemplateName($name);
                 $alternatives = $this->findAlternatives($shortname, $shortnames);
                 if (FilesystemLoader::MAIN_NAMESPACE !== $namespace) {
-                    $alternatives = array_map(function ($shortname) use ($namespace) {
-                        return '@'.$namespace.'/'.$shortname;
-                    }, $alternatives);
+                    $alternatives = array_map(fn ($shortname) => '@'.$namespace.'/'.$shortname, $alternatives);
                 }
             }
 
@@ -543,7 +541,7 @@ private function findAlternatives(string $name, array $collection): array
         }
 
         $threshold = 1e3;
-        $alternatives = array_filter($alternatives, function ($lev) use ($threshold) { return $lev < 2 * $threshold; });
+        $alternatives = array_filter($alternatives, fn ($lev) => $lev < 2 * $threshold);
         ksort($alternatives, \SORT_NATURAL | \SORT_FLAG_CASE);
 
         return array_keys($alternatives);

Extension/CodeExtension.php

@@ -120,9 +120,7 @@ public function fileExcerpt(string $file, int $line, int $srcContext = 3): ?stri
             // remove main code/span tags
             $code = preg_replace('#^<code.*?>\s*<span.*?>(.*)</span>\s*</code>#s', '\\1', $code);
             // split multiline spans
-            $code = preg_replace_callback('#<span ([^>]++)>((?:[^<]*+<br \/>)++[^<]*+)</span>#', function ($m) {
-                return "<span $m[1]>".str_replace('<br />', "</span><br /><span $m[1]>", $m[2]).'</span>';
-            }, $code);
+            $code = preg_replace_callback('#<span ([^>]++)>((?:[^<]*+<br \/>)++[^<]*+)</span>#', fn ($m) => "<span $m[1]>".str_replace('<br />', "</span><br /><span $m[1]>", $m[2]).'</span>', $code);
             $content = explode('<br />', $code);
 
             $lines = [];
@@ -188,9 +186,7 @@ public function getFileRelative(string $file): ?string
 
     public function formatFileFromText(string $text): string
     {
-        return preg_replace_callback('/in ("|&quot;)?(.+?)\1(?: +(?:on|at))? +line (\d+)/s', function ($match) {
-            return 'in '.$this->formatFile($match[2], $match[3]);
-        }, $text);
+        return preg_replace_callback('/in ("|&quot;)?(.+?)\1(?: +(?:on|at))? +line (\d+)/s', fn ($match) => 'in '.$this->formatFile($match[2], $match[3]), $text);
     }
 
     /**

Tests/Command/LintCommandTest.php

@@ -159,9 +159,7 @@ private function createCommandTester(): CommandTester
     private function createCommand(): Command
     {
         $environment = new Environment(new FilesystemLoader(\dirname(__DIR__).'/Fixtures/templates/'));
-        $environment->addFilter(new TwigFilter('deprecated_filter', function ($v) {
-            return $v;
-        }, ['deprecated' => true]));
+        $environment->addFilter(new TwigFilter('deprecated_filter', fn ($v) => $v, ['deprecated' => true]));
 
         $command = new LintCommand($environment);
 

Tests/Extension/AbstractBootstrap3LayoutTest.php

@@ -1039,9 +1039,7 @@ public function testSingleChoiceExpandedWithLabelsSetFalseByCallable()
     {
         $form = $this->factory->createNamed('name', 'Symfony\Component\Form\Extension\Core\Type\ChoiceType', '&a', [
             'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
-            'choice_label' => function () {
-                return false;
-            },
+            'choice_label' => fn () => false,
             'multiple' => false,
             'expanded' => true,
         ]);
@@ -1404,9 +1402,7 @@ public function testMultipleChoiceExpandedWithLabelsSetFalseByCallable()
     {
         $form = $this->factory->createNamed('name', 'Symfony\Component\Form\Extension\Core\Type\ChoiceType', ['&a'], [
             'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
-            'choice_label' => function () {
-                return false;
-            },
+            'choice_label' => fn () => false,
             'multiple' => true,
             'expanded' => true,
         ]);

Tests/Extension/AbstractBootstrap4LayoutTest.php

@@ -580,9 +580,7 @@ public function testSingleChoiceExpandedWithLabelsSetFalseByCallable()
     {
         $form = $this->factory->createNamed('name', ChoiceType::class, '&a', [
             'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
-            'choice_label' => function () {
-                return false;
-            },
+            'choice_label' => fn () => false,
             'multiple' => false,
             'expanded' => true,
         ]);
@@ -901,9 +899,7 @@ public function testMultipleChoiceExpandedWithLabelsSetFalseByCallable()
     {
         $form = $this->factory->createNamed('name', ChoiceType::class, ['&a'], [
             'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
-            'choice_label' => function () {
-                return false;
-            },
+            'choice_label' => fn () => false,
             'multiple' => true,
             'expanded' => true,
         ]);

Tests/Mime/BodyRendererTest.php

@@ -124,9 +124,7 @@ public function testRenderedOnceUnserializableContext()
         ;
         $email->textTemplate('text');
         $email->context([
-            'foo' => static function () {
-                return 'bar';
-            },
+            'foo' => static fn () => 'bar',
         ]);
 
         $renderer->render($email);

UndefinedCallableHandler.php

@@ -87,7 +87,7 @@ public static function onUndefinedFunction(string $name): TwigFunction|false
         }
 
         if ('webpack-encore-bundle' === self::FUNCTION_COMPONENTS[$name]) {
-            return new TwigFunction($name, static function () { return ''; });
+            return new TwigFunction($name, static fn () => '');
         }
 
         throw new SyntaxError(self::onUndefined($name, 'function', self::FUNCTION_COMPONENTS[$name]));