forbidUnusedMatchResult: fix false positive for usage in arrow function (#305)

Author: maryo

src/Visitor/UnusedMatchVisitor.php

@@ -5,6 +5,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Arg;
 use PhpParser\Node\ArrayItem;
+use PhpParser\Node\Expr\ArrowFunction;
 use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\BinaryOp\Coalesce;
@@ -86,7 +87,8 @@ private function isUsed(Node $parent): bool
             || $parent instanceof Ternary
             || $parent instanceof MatchArm
             || $parent instanceof Yield_
-            || $parent instanceof YieldFrom;
+            || $parent instanceof YieldFrom
+            || $parent instanceof ArrowFunction;
     }
 
 }

tests/Rule/data/ForbidUnusedMatchResultRule/code.php

@@ -70,6 +70,18 @@ public function testUsed(bool $bool): mixed
             1 => 'y',
         } : null;
 
+        function ($int) {
+            return match ($int) {
+                0 => 'x',
+                1 => 'y',
+            };
+        };
+
+        fn () => match ($int) {
+            0 => 'x',
+            1 => 'y',
+        };
+
         return match ($bool) {
             false => 1,
             true => 2,