[CodeQuality] Skip same boolean in both branches in SimplifyIfReturnBoolRector

Author: TomasVotruba

rules-tests/CodeQuality/Rector/If_/SimplifyIfReturnBoolRector/Fixture/skip_same_bool_return.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\If_\SimplifyIfReturnBoolRector\Fixture;
+
+function skipSameBoolReturnFalse(): false
+{
+    return false;
+}
+
+function skipSameBoolReturn(): bool
+{
+    if (! skipSameBoolReturnFalse()) {
+        return true;
+    }
+
+    return true;
+}

rules/CodeQuality/Rector/If_/SimplifyIfReturnBoolRector.php

@@ -141,6 +141,13 @@ private function shouldSkipIfAndReturn(If_ $if, Return_ $return): bool
             return true;
         }
 
+        // both branches return the same boolean → condition is pointless, transform would be unsound
+        if ($this->valueResolver->isTrueOrFalse($return->expr) && $this->valueResolver->isTrue(
+            $returnedExpr
+        ) === $this->valueResolver->isTrue($return->expr)) {
+            return true;
+        }
+
         // negate + negate → skip for now
         if (! $this->valueResolver->isFalse($returnedExpr)) {
             return ! $this->valueResolver->isTrueOrFalse($return->expr);