[DeadCode] Add SimplifyIfElseWithSameContentRector

config/set/dead-code/dead-code.yaml

@@ -29,3 +29,4 @@ services:
 
     Rector\DeadCode\Rector\Property\RemoveNullPropertyInitializationRector: ~
     Rector\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector: ~
+    Rector\DeadCode\Rector\If_\SimplifyIfElseWithSameContentRector: ~

packages/DeadCode/src/Rector/If_/SimplifyIfElseWithSameContentRector.php

@@ -0,0 +1,93 @@
+<?php declare(strict_types=1);
+
+namespace Rector\DeadCode\Rector\If_;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\If_;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see \Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\SimplifyIfElseWithSameContentRectorTest
+ */
+final class SimplifyIfElseWithSameContentRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Remove if/else if they have same content', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+        if (true) {
+            return 1;
+        } else {
+            return 1;
+        }
+    }
+}
+PHP
+                ,
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+        return 1;
+    }
+}
+PHP
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [If_::class];
+    }
+
+    /**
+     * @param If_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($node->else === null) {
+            return null;
+        }
+
+        if (! $this->isIfWithConstantReturns($node)) {
+            return null;
+        }
+
+        foreach ($node->stmts as $stmt) {
+            $this->addNodeBeforeNode($stmt, $node);
+        }
+
+        $this->removeNode($node);
+
+        return $node;
+    }
+
+    private function isIfWithConstantReturns(If_ $if): bool
+    {
+        $possibleContents = [];
+        $possibleContents[] = $this->print($if->stmts);
+
+        foreach ($if->elseifs as $elseif) {
+            $possibleContents[] = $this->print($elseif->stmts);
+        }
+
+        $possibleContents[] = $this->print($if->else->stmts);
+
+        $uniqueContents = array_unique($possibleContents);
+
+        // only one content for all
+        return count($uniqueContents) === 1;
+    }
+}

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/fixture.php.inc

@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+        if (true) {
+            return 1;
+        } else {
+            return 1;
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+        return 1;
+    }
+}
+
+?>

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/skip_different_content.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SkipDifferentContent
+{
+    public function run()
+    {
+        if (true) {
+            return 1;
+        } else {
+            return 2;
+        }
+    }
+}

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/skip_else_with_no_return.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SkipElseWithNoReturn
+{
+    public function go()
+    {
+        if (true) {
+            return 1;
+        } else {
+            $value = 10;
+        }
+    }
+}

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/skip_missing_else.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SkipMissingElse
+{
+    public function go()
+    {
+        if (true) {
+            return 1;
+        } elseif (false) {
+            return 1;
+        }
+    }
+}

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/skip_more_than_return.php.inc

@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class SkipMoreThanReturn
+{
+    public function go()
+    {
+        if (true) {
+            return 1;
+        } else {
+            $also = 5;
+            return 1;
+        }
+    }
+}

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/Fixture/with_else_ifs.php.inc

@@ -0,0 +1,51 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class WithElseIfs
+{
+    public function run()
+    {
+        if (true) {
+            return 1;
+        } elseif (false) {
+            return 1;
+        } else {
+            return 1;
+        }
+    }
+
+    public function go()
+    {
+        if (true) {
+            return 1;
+        } elseif (false) {
+            return 1;
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector\Fixture;
+
+class WithElseIfs
+{
+    public function run()
+    {
+        return 1;
+    }
+
+    public function go()
+    {
+        if (true) {
+            return 1;
+        } elseif (false) {
+            return 1;
+        }
+    }
+}
+
+?>

packages/DeadCode/tests/Rector/If_/SimplifyIfElseWithSameContentRector/SimplifyIfElseWithSameContentRectorTest.php

@@ -0,0 +1,33 @@
+<?php declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\If_\SimplifyIfElseWithSameContentRector;
+
+use Iterator;
+use Rector\DeadCode\Rector\If_\SimplifyIfElseWithSameContentRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class SimplifyIfElseWithSameContentRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideDataForTest()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideDataForTest(): Iterator
+    {
+        yield [__DIR__ . '/Fixture/fixture.php.inc'];
+        yield [__DIR__ . '/Fixture/with_else_ifs.php.inc'];
+        yield [__DIR__ . '/Fixture/skip_different_content.php.inc'];
+        yield [__DIR__ . '/Fixture/skip_missing_else.php.inc'];
+        yield [__DIR__ . '/Fixture/skip_else_with_no_return.php.inc'];
+        yield [__DIR__ . '/Fixture/skip_more_than_return.php.inc'];
+    }
+
+    protected function getRectorClass(): string
+    {
+        return SimplifyIfElseWithSameContentRector::class;
+    }
+}

src/PhpParser/Node/Commander/NodeAddingCommander.php

@@ -88,6 +88,12 @@ final class NodeAddingCommander implements CommanderInterface
             return spl_object_hash($node);
         }
 
+        // special case for "If_"
+        $parentNode = $node->getAttribute(AttributeKey::CURRENT_EXPRESSION);
+        if ($parentNode === null) {
+            return spl_object_hash($node);
+        }
+
         /** @var Expression|null $foundNode */
         $foundNode = $this->betterNodeFinder->findFirstAncestorInstanceOf($node, Expression::class);
         if ($foundNode === null) {