[TypeDeclaration] Add AddFunctionReturnTypeRector

composer.json

@@ -11,7 +11,7 @@
         "jetbrains/phpstorm-stubs": "^2019.1",
         "nette/robot-loader": "^3.1",
         "nette/utils": "^2.5|^3.0",
-        "nikic/php-parser": "^4.2.1",
+        "nikic/php-parser": "dev-master",
         "phpstan/phpdoc-parser": "0.3.3",
         "phpstan/phpstan": "0.11.6",
         "sebastian/diff": "^3.0",

config/level/php/php74.yaml

@@ -16,3 +16,4 @@ services:
     Rector\Php\Rector\Double\RealToFloatTypeCastRector: ~
     Rector\Php\Rector\Assign\NullCoalescingOperatorRector: ~
     Rector\Php\Rector\Function_\ReservedFnFunctionRector: ~
+    Rector\Php\Rector\Closure\ClosureToArrowFunctionRector: ~

packages/ContributorTools/src/Command/DumpNodesCommand.php

@@ -176,6 +176,11 @@ final class DumpNodesCommand extends AbstractCommand
 
             if ($contructorReflection->getNumberOfRequiredParameters() === 0) {
                 $node = $nodeClassReflection->newInstance();
+                // special case
+                if ($node instanceof Node\Expr\ArrowFunction) {
+                    $node->expr = new LNumber(1);
+                }
+
                 $category = $this->resolveCategoryByNodeClass($nodeClass);
                 $this->nodeInfoResult->addNodeInfo($category, new NodeInfo(
                     $nodeClass,

packages/Php/src/Rector/Closure/ClosureToArrowFunctionRector.php

@@ -0,0 +1,134 @@
+<?php declare(strict_types=1);
+
+namespace Rector\Php\Rector\Closure;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\ArrowFunction;
+use PhpParser\Node\Expr\Closure;
+use PhpParser\Node\Expr\ClosureUse;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt\Return_;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see https://wiki.php.net/rfc/arrow_functions_v2
+ */
+final class ClosureToArrowFunctionRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Change closure to arrow function', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run($meetups)
+    {
+        return array_filter($meetups, function (Meetup $meetup) {
+            return is_object($meetup);
+        });
+    }
+}
+CODE_SAMPLE
+                ,
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run($meetups)
+    {
+        return array_filter($meetups, fn(Meetup $meetup) => is_object($meetup));
+    }
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Closure::class];
+    }
+
+    /**
+     * @param Closure $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $this->isAtLeastPhpVersion('7.4')) {
+            return null;
+        }
+
+        if (count((array) $node->stmts) !== 1) {
+            return null;
+        }
+
+        if (! $node->stmts[0] instanceof Return_) {
+            return null;
+        }
+
+        /** @var Return_ $return */
+        $return = $node->stmts[0];
+        if ($return->expr === null) {
+            return null;
+        }
+
+        if ($this->shouldSkipForUsedReferencedValue($node, $return)) {
+            return null;
+        }
+
+        $arrowFunction = new ArrowFunction();
+        $arrowFunction->params = $node->params;
+        $arrowFunction->returnType = $node->returnType;
+        $arrowFunction->byRef = $node->byRef;
+
+        $arrowFunction->expr = $return->expr;
+
+        return $arrowFunction;
+    }
+
+    private function shouldSkipForUsedReferencedValue(Closure $closure, Return_ $return): bool
+    {
+        if ($return->expr === null) {
+            return false;
+        }
+
+        $referencedValues = $this->resolveReferencedUseVariablesFromClosure($closure);
+        if ($referencedValues === []) {
+            return false;
+        }
+
+        return (bool) $this->betterNodeFinder->findFirst([$return->expr], function (Node $node) use (
+            $referencedValues
+        ): bool {
+            foreach ($referencedValues as $referencedValue) {
+                if ($this->areNodesEqual($node, $referencedValue)) {
+                    return true;
+                }
+            }
+
+            return false;
+        });
+    }
+
+    /**
+     * @return Variable[]
+     */
+    private function resolveReferencedUseVariablesFromClosure(Closure $closure): array
+    {
+        $referencedValues = [];
+
+        /** @var ClosureUse $use */
+        foreach ((array) $closure->uses as $use) {
+            if ($use->byRef) {
+                $referencedValues[] = $use->var;
+            }
+        }
+
+        return $referencedValues;
+    }
+}

packages/Php/tests/Rector/Closure/ClosureToArrowFunctionRector/ClosureToArrowFunctionRectorTest.php

@@ -0,0 +1,25 @@
+<?php declare(strict_types=1);
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector;
+
+use Rector\Php\Rector\Closure\ClosureToArrowFunctionRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class ClosureToArrowFunctionRectorTest extends AbstractRectorTestCase
+{
+    public function test(): void
+    {
+        $this->doTestFiles([
+            __DIR__ . '/Fixture/fixture.php.inc',
+            __DIR__ . '/Fixture/referenced_but_not_used.php.inc',
+            // skip
+            __DIR__ . '/Fixture/skip_no_return.php.inc',
+            __DIR__ . '/Fixture/skip_referenced_value.php.inc',
+        ]);
+    }
+
+    protected function getRectorClass(): string
+    {
+        return ClosureToArrowFunctionRector::class;
+    }
+}

packages/Php/tests/Rector/Closure/ClosureToArrowFunctionRector/Fixture/fixture.php.inc

@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class SomeClass
+{
+    public function run($meetups)
+    {
+        return array_filter($meetups, function (Meetup $meetup) {
+            return is_object($meetup);
+        });
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class SomeClass
+{
+    public function run($meetups)
+    {
+        return array_filter($meetups, fn(Meetup $meetup) => is_object($meetup));
+    }
+}
+
+?>

packages/Php/tests/Rector/Closure/ClosureToArrowFunctionRector/Fixture/referenced_but_not_used.php.inc

@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class ReferencedButNotUsed
+{
+    public function run()
+    {
+        $callback = function($b) use(&$i) {
+            return ++$b;
+        };
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class ReferencedButNotUsed
+{
+    public function run()
+    {
+        $callback = fn($b) => ++$b;
+    }
+}
+
+?>

packages/Php/tests/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_no_return.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class SkipNoReturn
+{
+    public function run($meetups)
+    {
+        return array_filter($meetups, function (Meetup $meetup) {
+            is_object($meetup);
+        });
+
+        return array_filter($meetups, function (Meetup $meetup) {
+            return;
+        });
+    }
+}

packages/Php/tests/Rector/Closure/ClosureToArrowFunctionRector/Fixture/skip_referenced_value.php.inc

@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Php\Tests\Rector\Closure\ClosureToArrowFunctionRector\Fixture;
+
+class SkipReferencedValue
+{
+    public function run()
+    {
+        $callback = function() use(&$i) {
+            return ++$i;
+        };
+    }
+}

packages/Php/tests/Rector/Function_/ReservedFnFunctionRector/ReservedFnFunctionRectorTest.php

@@ -2,6 +2,7 @@
 
 namespace Rector\Php\Tests\Rector\Function_\ReservedFnFunctionRector;
 
+use PhpParser\Parser\Tokens;
 use Rector\Php\Rector\Function_\ReservedFnFunctionRector;
 use Rector\Testing\PHPUnit\AbstractRectorTestCase;
 
@@ -9,6 +10,10 @@ final class ReservedFnFunctionRectorTest extends AbstractRectorTestCase
 {
     public function test(): void
     {
+        if (defined(Tokens::class . '::T_FN')) {
+            $this->markTestSkipped('fn is reserved name in PHP 7.4');
+        }
+
         $this->doTestFiles([__DIR__ . '/Fixture/fixture.php.inc']);
     }
 

packages/TypeDeclaration/src/Rector/Closure/AddClosureReturnTypeRector.php

@@ -3,6 +3,7 @@
 namespace Rector\TypeDeclaration\Rector\Closure;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr\Closure;
 use PHPStan\Analyser\Scope;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Rector\PhpParser\Node\Manipulator\FunctionLikeManipulator;
@@ -58,11 +59,11 @@ CODE_SAMPLE
      */
     public function getNodeTypes(): array
     {
-        return [Node\Expr\Closure::class];
+        return [Closure::class];
     }
 
     /**
-     * @param Node\Expr\Closure $node
+     * @param Closure $node
      */
     public function refactor(Node $node): ?Node
     {

rector.yaml

@@ -15,5 +15,5 @@ parameters:
     php_version_features: '7.1'
 
 services:
-#    Rector\CodingStyle\Rector\Namespace_\ImportFullyQualifiedNamesRector: ~
-    Rector\TypeDeclaration\Rector\Closure\AddClosureReturnTypeRector: ~
+    Rector\CodingStyle\Rector\Namespace_\ImportFullyQualifiedNamesRector: ~
+#    Rector\TypeDeclaration\Rector\Closure\AddClosureReturnTypeRector: ~