Fix nullsafe transpile (#6101)

Co-authored-by: Tomas Votruba <tomas.vot@gmail.com>

docs/rector_rules_overview.md

@@ -4930,8 +4930,8 @@ Change nullsafe operator to ternary operator rector
 ```diff
 -$dateAsString = $booking->getStartDate()?->asDateTimeString();
 -$dateAsString = $booking->startDate?->dateTimeString;
-+$dateAsString = $booking->getStartDate() ? $booking->getStartDate()->asDateTimeString() : null;
-+$dateAsString = $booking->startDate ? $booking->startDate->dateTimeString : null;
++$dateAsString = ($_ = $booking->getStartDate()) ? $_->asDateTimeString() : null;
++$dateAsString = ($_ = $booking->startDate) ? $_->dateTimeString : null;
 ```
 
 <br>

rules-tests/DowngradePhp80/Rector/NullsafeMethodCall/DowngradeNullsafeToTernaryOperatorRector/Fixture/fixture.php.inc

@@ -17,6 +17,12 @@ class Fixture
 
         // all are property fetch
         $dateAsString = $booking->getStartDate?->asDateTimeString;
+
+        $getStartDate = true;
+        $bookingGetStartDate = true;
+
+        // previously named vars aren't reused
+        $dateAsString = $booking->getStartDate?->asDateTimeString;
     }
 }
 
@@ -31,16 +37,22 @@ class Fixture
     public function run($booking)
     {
         // with argument
-        $dateAsString = $booking->getStartDate($args1) ? $booking->getStartDate($args1)->asDateTimeString($arg2) : null;
+        $dateAsString = ($getStartDate = $booking->getStartDate($args1)) ? $getStartDate->asDateTimeString($arg2) : null;
 
         // without argument, one is method call, next property fetch
-        $dateAsString = $booking->getStartDate() ? $booking->getStartDate()->asDateTimeString : null;
+        $dateAsString = ($getStartDate = $booking->getStartDate()) ? $getStartDate->asDateTimeString : null;
 
         // without argument, one is property call, next method fetch
-        $dateAsString = $booking->getStartDate ? $booking->getStartDate->asDateTimeString() : null;
+        $dateAsString = ($bookingGetStartDate = $booking->getStartDate) ? $bookingGetStartDate->asDateTimeString() : null;
 
         // all are property fetch
-        $dateAsString = $booking->getStartDate ? $booking->getStartDate->asDateTimeString : null;
+        $dateAsString = ($bookingGetStartDate = $booking->getStartDate) ? $bookingGetStartDate->asDateTimeString : null;
+
+        $getStartDate = true;
+        $bookingGetStartDate = true;
+
+        // previously named vars aren't reused
+        $dateAsString = ($bookingGetStartDate2 = $booking->getStartDate) ? $bookingGetStartDate2->asDateTimeString : null;
     }
 }
 

rules-tests/DowngradePhp80/Rector/NullsafeMethodCall/DowngradeNullsafeToTernaryOperatorRector/Fixture/multiple_call.php.inc

@@ -21,8 +21,8 @@ class MultipleCall
 {
     public function run($object)
     {
-        $result = ($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null) ? ($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null)->otherCall($args3) : null;
-        $result = (($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null) ? ($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null)->otherCall($args3) : null) ? (($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null) ? ($object->multiple($args1) ? $object->multiple($args1)->call($args2) : null)->otherCall($args3) : null)->anotherCall($args4) : null;
+        $result = ($call = ($multiple = $object->multiple($args1)) ? $multiple->call($args2) : null) ? $call->otherCall($args3) : null;
+        $result = ($otherCall = ($call = ($multiple = $object->multiple($args1)) ? $multiple->call($args2) : null) ? $call->otherCall($args3) : null) ? $otherCall->anotherCall($args4) : null;
     }
 }
 

rules/DowngradePhp80/Rector/NullsafeMethodCall/DowngradeNullsafeToTernaryOperatorRector.php

@@ -5,12 +5,15 @@ declare(strict_types=1);
 namespace Rector\DowngradePhp80\Rector\NullsafeMethodCall;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\NullsafeMethodCall;
 use PhpParser\Node\Expr\NullsafePropertyFetch;
 use PhpParser\Node\Expr\PropertyFetch;
 use PhpParser\Node\Expr\Ternary;
 use Rector\Core\Rector\AbstractRector;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+use Rector\Php70\NodeAnalyzer\VariableNaming;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
 
@@ -19,6 +22,16 @@ use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
  */
 final class DowngradeNullsafeToTernaryOperatorRector extends AbstractRector
 {
+    /**
+     * @var VariableNaming
+     */
+    public $variableNaming;
+
+    public function __construct(VariableNaming $variableNaming)
+    {
+        $this->variableNaming = $variableNaming;
+    }
+
     public function getRuleDefinition(): RuleDefinition
     {
         return new RuleDefinition('Change nullsafe operator to ternary operator rector', [
@@ -29,8 +42,8 @@ $dateAsString = $booking->startDate?->dateTimeString;
 CODE_SAMPLE
 ,
                 <<<'CODE_SAMPLE'
-$dateAsString = $booking->getStartDate() ? $booking->getStartDate()->asDateTimeString() : null;
-$dateAsString = $booking->startDate ? $booking->startDate->dateTimeString : null;
+$dateAsString = ($bookingGetStartDate = $booking->getStartDate()) ? $bookingGetStartDate->asDateTimeString() : null;
+$dateAsString = ($bookingGetStartDate = $booking->startDate) ? $bookingGetStartDate->dateTimeString : null;
 CODE_SAMPLE
             ),
         ]);
@@ -49,10 +62,12 @@ CODE_SAMPLE
      */
     public function refactor(Node $node): ?Node
     {
+        $tempVarName = $this->variableNaming->resolveFromNodeWithScopeCountAndFallbackName($node->var, $node->getAttribute(AttributeKey::SCOPE), '_');
+        $tempVar = new Node\Expr\Variable($tempVarName);
         $called = $node instanceof NullsafeMethodCall
-            ? new MethodCall($node->var, $node->name, $node->args)
-            : new PropertyFetch($node->var, $node->name);
+            ? new MethodCall($tempVar, $node->name, $node->args)
+            : new PropertyFetch($tempVar, $node->name);
 
-        return new Ternary($node->var, $called, $this->nodeFactory->createNull());
+        return new Ternary(new Assign($tempVar, $node->var), $called, $this->nodeFactory->createNull());
     }
 }