Inspect constant() tests (not just function calls)

I was unaware the AST represents `is constant()` differently from
`== constant()`.

Therefore, `{{ 'foo' is constant('FOO') }}` did not trigger an error,
even though `{{ 'foo' == constant('FOO') }}` did.

Author: drjayvee

composer.json

@@ -8,7 +8,7 @@
             "name": "Jeroen Versteeg"
         }
     ],
-    "version": "1.0.5",
+    "version": "1.0.6",
     "autoload": {
         "psr-4": {
             "AlisQI\\TwigQI\\": "src/"

src/Inspection/InvalidConstant.php

@@ -8,6 +8,7 @@
 use Twig\Environment;
 use Twig\Node\Expression\ConstantExpression;
 use Twig\Node\Expression\FunctionExpression;
+use Twig\Node\Expression\Test\ConstantTest;
 use Twig\Node\Expression\Variable\ContextVariable;
 use Twig\Node\Node;
 use Twig\NodeVisitor\NodeVisitorInterface;
@@ -17,20 +18,24 @@ class InvalidConstant implements NodeVisitorInterface
     public function enterNode(Node $node, Environment $env): Node
     {
         if (
-            $node instanceof FunctionExpression &&
-            $node->getAttribute('name') === 'constant'
+            ($node instanceof FunctionExpression && $node->getAttribute('name') === 'constant') ||
+            $node instanceof ConstantTest
         ) {
             $this->checkArguments($node);
         }
 
         return $node;
     }
 
-    private function checkArguments(FunctionExpression $node): void
+    private function checkArguments(FunctionExpression|ConstantTest $node): void
     {
         $arguments = $node->getNode('arguments');
 
-        if ($node->getAttribute('is_defined_test')) {
+        // ignore `constant('foo') is defined`
+        if (
+            $node instanceof FunctionExpression &&
+            $node->getAttribute('is_defined_test')
+        ) {
             return;
         }
 

tests/InvalidConstantTest.php

@@ -29,6 +29,18 @@ public function test_itValidatesConstants(string $constant, bool $isValid): void
             implode(', ', $this->errors)
         );
     }
+    
+    /** @dataProvider getConstants */
+    public function test_itValidatesConstantTest(string $constant, bool $isValid): void
+    {
+        $this->env->createTemplate("{{ 'this' is constant('$constant') }}");
+
+        self::assertEquals(
+            $isValid,
+            empty($this->errors),
+            implode(', ', $this->errors)
+        );
+    }
 
     public static function getInvalidConstants(): array
     {