[CodingStyle] Add StaticClosureRector (#2658)

* [CodingStyle] Add StaticClosureRector

* regenerate docs

build/target-repository/docs/rector_rules_overview.md

@@ -1,4 +1,4 @@
-# 412 Rules Overview
+# 414 Rules Overview
 
 <br>
 
@@ -8,7 +8,7 @@
 
 - [CodeQuality](#codequality) (73)
 
-- [CodingStyle](#codingstyle) (35)
+- [CodingStyle](#codingstyle) (37)
 
 - [Compatibility](#compatibility) (1)
 
@@ -2339,6 +2339,38 @@ Separate constant and properties to own lines
 
 <br>
 
+### StaticArrowFunctionRector
+
+Changes ArrowFunction to be static when possible
+
+- class: [`Rector\CodingStyle\Rector\ArrowFunction\StaticArrowFunctionRector`](../rules/CodingStyle/Rector/ArrowFunction/StaticArrowFunctionRector.php)
+
+```diff
+-fn (): string => 'test';
++static fn (): string => 'test';
+```
+
+<br>
+
+### StaticClosureRector
+
+Changes Closure to be static when possible
+
+- class: [`Rector\CodingStyle\Rector\Closure\StaticClosureRector`](../rules/CodingStyle/Rector/Closure/StaticClosureRector.php)
+
+```diff
+-function () {
++static function () {
+     if (rand(0, 1)) {
+         return 1;
+     }
+
+     return 2;
+ }
+```
+
+<br>
+
 ### StrictArraySearchRector
 
 Makes array_search search for identical elements

config/set/coding-style.php

@@ -14,6 +14,7 @@
 use Rector\CodingStyle\Rector\ClassMethod\NewlineBeforeNewAssignSetRector;
 use Rector\CodingStyle\Rector\ClassMethod\RemoveDoubleUnderscoreInMethodNameRector;
 use Rector\CodingStyle\Rector\ClassMethod\UnSpreadOperatorRector;
+use Rector\CodingStyle\Rector\Closure\StaticClosureRector;
 use Rector\CodingStyle\Rector\Encapsed\EncapsedStringsToSprintfRector;
 use Rector\CodingStyle\Rector\Encapsed\WrapEncapsedVariableInCurlyBracesRector;
 use Rector\CodingStyle\Rector\FuncCall\CallUserFuncArrayToVariadicRector;
@@ -69,5 +70,6 @@
         CallUserFuncArrayToVariadicRector::class,
         VersionCompareFuncCallToConstantRector::class,
         StaticArrowFunctionRector::class,
+        StaticClosureRector::class,
     ]);
 };

rules-tests/CodingStyle/Rector/Closure/StaticClosureRector/Fixture/fixture.php.inc

@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector\Fixture;
+
+function () {
+    if (rand(0, 1)) {
+        return 1;
+    }
+    return 2;
+};
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector\Fixture;
+
+static function () {
+    if (rand(0, 1)) {
+        return 1;
+    }
+    return 2;
+};
+
+?>

rules-tests/CodingStyle/Rector/Closure/StaticClosureRector/Fixture/skip_already_static.php.inc

@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector\Fixture;
+
+static function () {
+    if (rand(0, 1)) {
+        return 1;
+    }
+
+    return 2;
+};

rules-tests/CodingStyle/Rector/Closure/StaticClosureRector/Fixture/skip_with_this.php.inc

@@ -0,0 +1,19 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector\Fixture;
+
+class SkipWithThis
+{
+    private $data = 'data';
+
+    public function run()
+    {
+        function () {
+            if (rand(0, 1)) {
+                return $this->data;
+            }
+
+            return strtoupper($this->data);
+        };
+    }
+}

rules-tests/CodingStyle/Rector/Closure/StaticClosureRector/StaticClosureRectorTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+final class StaticClosureRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    /**
+     * @return Iterator<SmartFileInfo>
+     */
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

rules-tests/CodingStyle/Rector/Closure/StaticClosureRector/config/configured_rule.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\CodingStyle\Rector\Closure\StaticClosureRector;
+use Rector\Config\RectorConfig;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(StaticClosureRector::class);
+};

rules/CodingStyle/Rector/Closure/StaticClosureRector.php

@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodingStyle\Rector\Closure;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Closure;
+use PhpParser\Node\Expr\Variable;
+use Rector\Core\Rector\AbstractRector;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @see \Rector\Tests\CodingStyle\Rector\Closure\StaticClosureRector\StaticClosureRectorTest
+ */
+final class StaticClosureRector extends AbstractRector
+{
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition(
+            'Changes Closure to be static when possible',
+            [
+                new CodeSample(
+                    <<<'CODE_SAMPLE'
+function () {
+    if (rand(0, 1)) {
+        return 1;
+    }
+
+    return 2;
+}
+CODE_SAMPLE
+                    ,
+                    <<<'CODE_SAMPLE'
+static function () {
+    if (rand(0, 1)) {
+        return 1;
+    }
+
+    return 2;
+}
+CODE_SAMPLE
+                ),
+            ]
+        );
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [Closure::class];
+    }
+
+    /**
+     * @param Closure $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($this->shouldSkip($node)) {
+            return null;
+        }
+
+        $node->static = true;
+        return $node;
+    }
+
+    private function shouldSkip(Closure $closure): bool
+    {
+        if ($closure->static) {
+            return true;
+        }
+
+        return (bool) $this->betterNodeFinder->findFirst(
+            $closure->stmts,
+            static fn (Node $subNode): bool => $subNode instanceof Variable && $subNode->name === 'this'
+        );
+    }
+}