[EarlyReturn] Add ReturnEarlyIfVariableRector

config/set/early-return.php

@@ -14,6 +14,7 @@
 use Rector\EarlyReturn\Rector\Return_\PreparedValueToEarlyReturnRector;
 use Rector\EarlyReturn\Rector\Return_\ReturnBinaryAndToEarlyReturnRector;
 use Rector\EarlyReturn\Rector\Return_\ReturnBinaryOrToEarlyReturnRector;
+use Rector\EarlyReturn\Rector\StmtsAwareInterface\ReturnEarlyIfVariableRector;
 
 return static function (RectorConfig $rectorConfig): void {
     $rectorConfig->rule(ChangeNestedForeachIfsToEarlyContinueRector::class);
@@ -27,4 +28,5 @@
     $rectorConfig->rule(ReturnAfterToEarlyOnBreakRector::class);
     $rectorConfig->rule(PreparedValueToEarlyReturnRector::class);
     $rectorConfig->rule(ReturnBinaryOrToEarlyReturnRector::class);
+    $rectorConfig->rule(ReturnEarlyIfVariableRector::class);
 };

rules-tests/EarlyReturn/Rector/StmtsAwareInterface/ReturnEarlyIfVariableRector/Fixture/some_class.php.inc

@@ -0,0 +1,35 @@
+<?php
+
+namespace Rector\Tests\EarlyReturn\Rector\StmtsAwareInterface\ReturnEarlyIfVariableRector\Fixture;
+
+final class SomeClass
+{
+    public function run($value)
+    {
+        if ($value === 50) {
+            $value = 100;
+        }
+
+        return $value;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\EarlyReturn\Rector\StmtsAwareInterface\ReturnEarlyIfVariableRector\Fixture;
+
+final class SomeClass
+{
+    public function run($value)
+    {
+        if ($value === 50) {
+            return 100;
+        }
+
+        return $value;
+    }
+}
+
+?>

rules-tests/EarlyReturn/Rector/StmtsAwareInterface/ReturnEarlyIfVariableRector/ReturnEarlyIfVariableRectorTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\EarlyReturn\Rector\StmtsAwareInterface\ReturnEarlyIfVariableRector;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+final class ReturnEarlyIfVariableRectorTest 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/EarlyReturn/Rector/StmtsAwareInterface/ReturnEarlyIfVariableRector/config/configured_rule.php

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

rules/EarlyReturn/Rector/StmtsAwareInterface/ReturnEarlyIfVariableRector.php

@@ -0,0 +1,148 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\EarlyReturn\Rector\StmtsAwareInterface;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\Return_;
+use Rector\Core\Contract\PhpParser\Node\StmtsAwareInterface;
+use Rector\Core\Rector\AbstractRector;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @see \Rector\Tests\EarlyReturn\Rector\StmtsAwareInterface\ReturnEarlyIfVariableRector\ReturnEarlyIfVariableRectorTest
+ */
+final class ReturnEarlyIfVariableRector extends AbstractRector
+{
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition('Replace if conditioned variable override with direct return', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+final class SomeClass
+{
+    public function run($value)
+    {
+        if ($value === 50) {
+            $value = 100;
+        }
+
+        return $value;
+    }
+}
+CODE_SAMPLE
+
+                ,
+                <<<'CODE_SAMPLE'
+final class SomeClass
+{
+    public function run($value)
+    {
+        if ($value === 50) {
+            return 100;
+        }
+
+        return $value;
+    }
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [StmtsAwareInterface::class];
+    }
+
+    /**
+     * @param StmtsAwareInterface $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        $stmts = (array) $node->stmts;
+
+        foreach ($stmts as $key => $stmt) {
+            $returnVariable = $this->matchNextStmtReturnVariable($node, $key);
+            if (! $returnVariable instanceof Variable) {
+                continue;
+            }
+
+            if ($stmt instanceof If_ && $stmt->else === null && $stmt->elseifs === []) {
+                // is single condition if
+                $if = $stmt;
+                if (count($if->stmts) !== 1) {
+                    continue;
+                }
+
+                $onlyIfStmt = $if->stmts[0];
+                $assignedExpr = $this->matchOnlyIfStmtReturnExpr($onlyIfStmt, $returnVariable);
+                if (! $assignedExpr instanceof Expr) {
+                    continue;
+                }
+
+                $if->stmts[0] = new Return_($assignedExpr);
+                return $node;
+            }
+        }
+
+        return null;
+    }
+
+    private function matchOnlyIfStmtReturnExpr(Stmt $onlyIfStmt, Variable $returnVariable): Expr|null
+    {
+        if (! $onlyIfStmt instanceof Expression) {
+            return null;
+        }
+
+        if (! $onlyIfStmt->expr instanceof Assign) {
+            return null;
+        }
+
+        $assign = $onlyIfStmt->expr;
+
+        // assign to same variable that is returned
+        if (! $assign->var instanceof Variable) {
+            return null;
+        }
+
+        if (! $this->nodeComparator->areNodesEqual($assign->var, $returnVariable)) {
+            return null;
+        }
+
+        // return directly
+        return $assign->expr;
+    }
+
+    private function matchNextStmtReturnVariable(StmtsAwareInterface $stmtsAware, int $key): Variable|null
+    {
+        $nextStmt = $stmtsAware->stmts[$key + 1] ?? null;
+
+        // last item → stop
+        if ($nextStmt === null) {
+            return null;
+        }
+
+        if (! $nextStmt instanceof Return_) {
+            return null;
+        }
+
+        // next return must be variable
+        if (! $nextStmt->expr instanceof Variable) {
+            return null;
+        }
+
+        return $nextStmt->expr;
+    }
+}