Fix transitive trait coverage for enums

Author: no-simpler

src/StaticAnalysis/Visitor/CodeUnitFindingVisitor.php

@@ -105,7 +105,7 @@ public function leaveNode(Node $node): null
             return null;
         }
 
-        if (!$node instanceof Class_ && !$node instanceof Trait_) {
+        if (!$node instanceof Class_ && !$node instanceof Enum_ && !$node instanceof Trait_) {
             return null;
         }
 
@@ -396,11 +396,11 @@ private function typeAsString(Identifier|Name $node): string
     /**
      * @param list<non-empty-string> $traits
      */
-    private function postProcessClassOrTrait(Class_|Trait_ $node, array $traits): void
+    private function postProcessClassOrTrait(Class_|Enum_|Trait_ $node, array $traits): void
     {
         $name = $node->namespacedName->toString();
 
-        if ($node instanceof Class_) {
+        if ($node instanceof Class_ || $node instanceof Enum_) {
             assert(isset($this->classes[$name]));
 
             $this->classes[$name] = new \SebastianBergmann\CodeCoverage\StaticAnalysis\Class_(

tests/_files/source_with_enum_using_trait.php

@@ -0,0 +1,17 @@
+<?php declare(strict_types=1);
+namespace SebastianBergmann\CodeCoverage\TestFixture;
+
+trait EnumTrait
+{
+    public function traitMethod(): string
+    {
+        return 'from trait';
+    }
+}
+
+enum EnumWithTrait: string
+{
+    use EnumTrait;
+
+    case Foo = 'foo';
+}

tests/tests/StaticAnalysis/Visitor/CodeUnitFindingVisitorTest.php

@@ -255,6 +255,22 @@ public function testDetailsAboutExtendedClassesImplementedInterfacesAndUsedTrait
         $this->assertArrayHasKey('six', $methods);
     }
 
+    public function testHandlesEnumUsingTrait(): void
+    {
+        $codeUnitFindingVisitor = $this->findCodeUnits(__DIR__ . '/../../../_files/source_with_enum_using_trait.php');
+
+        $classes = $codeUnitFindingVisitor->classes();
+
+        $this->assertCount(1, $classes);
+
+        $enum = $classes['SebastianBergmann\CodeCoverage\TestFixture\EnumWithTrait'];
+
+        $this->assertSame(
+            ['SebastianBergmann\CodeCoverage\TestFixture\EnumTrait'],
+            $enum->traits(),
+        );
+    }
+
     private function findCodeUnits(string $filename): CodeUnitFindingVisitor
     {
         $nodes = (new ParserFactory)->createForHostVersion()->parse(