InvalidDotOperation ignores non-constant attributes

The inspection threw an Exception if the `GetAttrExpression`'s attribute
was not a `ConstantExpression`, such as
```
{{ foo.('bar' ?: 'baz') }}
```

Fixes #4

Author: drjayvee

composer.json

@@ -8,7 +8,7 @@
             "name": "Jeroen Versteeg"
         }
     ],
-    "version": "2.0.0",
+    "version": "2.0.1",
     "autoload": {
         "psr-4": {
             "AlisQI\\TwigQI\\": "src/"

src/Inspection/InvalidDotOperation.php

@@ -10,7 +10,9 @@
 use ReflectionClass;
 use Twig\Environment;
 use Twig\Node\Expression\ArrowFunctionExpression;
+use Twig\Node\Expression\ConstantExpression;
 use Twig\Node\Expression\GetAttrExpression;
+use Twig\Node\Expression\NameExpression;
 use Twig\Node\Expression\Variable\ContextVariable;
 use Twig\Node\ForNode;
 use Twig\Node\MacroNode;
@@ -73,11 +75,12 @@ public function enterNode(Node $node, Environment $env): Node
         if (
             $node instanceof GetAttrExpression &&
             $node->getAttribute('type') !== Template::ARRAY_CALL &&
-            ($nameNode = $node->getNode('node')) instanceof ContextVariable
+            ($nameNode = $node->getNode('node')) instanceof ContextVariable &&
+            ($attributeNode = $node->getNode('attribute')) instanceof ConstantExpression
         ) {
             $location = new NodeLocation($node);
             $name = $nameNode->getAttribute('name');
-            $attribute = $node->getNode('attribute')->getAttribute('value');
+            $attribute = $attributeNode->getAttribute('value');
             $this->checkOperation($name, $attribute, $location);
         }
 
@@ -97,7 +100,7 @@ private function checkOperation(string $name, string $attribute, NodeLocation $l
         if (str_starts_with($type, '?')) {
             $type = substr($type, 1);
         }
-        
+
         if (in_array($type, self::UNSUPPORTED_TYPES)) {
             trigger_error(
                 sprintf('Invalid dot operation on unsupported type \'%s\' (at %s)', $type, $location),
@@ -187,7 +190,7 @@ private function extractScopedVariableTypes(ArrowFunctionExpression|ForNode|SetN
         }
 
         if ($node instanceof ForNode) {
-            $keyName   = $node->getNode('key_target')  ->getAttribute('name');
+            $keyName = $node->getNode('key_target')->getAttribute('name');
             $valueName = $node->getNode('value_target')->getAttribute('name');
 
             $keyType = $valueType = 'mixed';

tests/InvalidDotOperationTest.php

@@ -31,6 +31,30 @@ public function test_itIgnoresAttributesOnExpressions(): void
         );
     }
 
+    public function test_itIgnoresEnumCaseValues(): void
+    {
+        $this->env->createTemplate(<<<EOF
+            {{ enum('\\\\AlisQI\\\\TwigQI\\\\Tests\\\\Type\\\\Enom').This.value }}
+        EOF);
+
+        self::assertEmpty(
+            $this->errors,
+            implode(', ', $this->errors)
+        );
+    }
+    
+    public function test_itIgnoresAttributeExpressions(): void
+    {
+        $this->env->createTemplate(<<<EOF
+            {{ foo.('bar' ?: 'baz') }}
+        EOF);
+
+        self::assertEmpty(
+            $this->errors,
+            implode(', ', $this->errors)
+        );
+    }
+
     public function test_itIgnoresUndeclaredVariables(): void
     {
         $this->env->createTemplate(<<<EOF

tests/Type/Enom.php

@@ -4,7 +4,7 @@
 
 namespace AlisQI\TwigQI\Tests\Type;
 
-enum Enom {
-    case This;
-    case That;
+enum Enom: string {
+    case This = 'this';
+    case That = 'that';
 }