Add support for registered undefined element callbacks in tests

CHANGELOG

@@ -2,6 +2,7 @@
 
  * Fix wrong array index
  * Bump minimum PHP version to 8.1
+ * Add support for registering callbacks for undefined functions, filters or token parsers in the IntegrationTestCase
 
 # 3.19.0 (2025-01-28)
 
@@ -44,7 +45,7 @@
  * Deprecate returning `null` from `TwigFilter::getSafe()` and `TwigFunction::getSafe()`, return `[]` instead
 
 # 3.15.0 (2024-11-17)
- 
+
  * [BC BREAK] Add support for accessing class constants with the dot operator;
    this can be a BC break if you don't use UPPERCASE constant names
  * Add Spanish inflector support for the `plural` and `singular` filters in the String extension

src/Environment.php

@@ -736,6 +736,9 @@ class Environment
         return $this->extensionSet->getTokenParser($name);
     }
 
+    /**
+     * @param callable(string): (TokenParserInterface|false) $callable
+     */
     public function registerUndefinedTokenParserCallback(callable $callable): void
     {
         $this->extensionSet->registerUndefinedTokenParserCallback($callable);
@@ -775,6 +778,9 @@ class Environment
         return $this->extensionSet->getFilter($name);
     }
 
+    /**
+     * @param callable(string): (TwigFilter|false) $callable
+     */
     public function registerUndefinedFilterCallback(callable $callable): void
     {
         $this->extensionSet->registerUndefinedFilterCallback($callable);
@@ -838,6 +844,9 @@ class Environment
         return $this->extensionSet->getFunction($name);
     }
 
+    /**
+     * @param callable(string): (TwigFunction|false) $callable
+     */
     public function registerUndefinedFunctionCallback(callable $callable): void
     {
         $this->extensionSet->registerUndefinedFunctionCallback($callable);

src/ExtensionSet.php

@@ -52,8 +52,11 @@ final class ExtensionSet
     private $binaryOperators;
     /** @var array<string, mixed>|null */
     private $globals;
+    /** @var array<callable(string): (TwigFunction|false)> */
     private $functionCallbacks = [];
+    /** @var array<callable(string): (TwigFilter|false)> */
     private $filterCallbacks = [];
+    /** @var array<callable(string): (TokenParserInterface|false)> */
     private $parserCallbacks = [];
     private $lastModified = 0;
 
@@ -198,6 +201,9 @@ final class ExtensionSet
         return null;
     }
 
+    /**
+     * @param callable(string): (TwigFunction|false) $callable
+     */
     public function registerUndefinedFunctionCallback(callable $callable): void
     {
         $this->functionCallbacks[] = $callable;
@@ -251,6 +257,9 @@ final class ExtensionSet
         return null;
     }
 
+    /**
+     * @param callable(string): (TwigFilter|false) $callable
+     */
     public function registerUndefinedFilterCallback(callable $callable): void
     {
         $this->filterCallbacks[] = $callable;
@@ -317,6 +326,9 @@ final class ExtensionSet
         return null;
     }
 
+    /**
+     * @param callable(string): (TokenParserInterface|false) $callable
+     */
     public function registerUndefinedTokenParserCallback(callable $callable): void
     {
         $this->parserCallbacks[] = $callable;

src/Test/IntegrationTestCase.php

@@ -17,6 +17,7 @@ use Twig\Error\Error;
 use Twig\Extension\ExtensionInterface;
 use Twig\Loader\ArrayLoader;
 use Twig\RuntimeLoader\RuntimeLoaderInterface;
+use Twig\TokenParser\TokenParserInterface;
 use Twig\TwigFilter;
 use Twig\TwigFunction;
 use Twig\TwigTest;
@@ -84,6 +85,30 @@ abstract class IntegrationTestCase extends TestCase
         return [];
     }
 
+    /**
+     * @return array<callable(string): (TwigFilter|false)>
+     */
+    protected function getUndefinedFilterCallbacks(): array
+    {
+        return [];
+    }
+
+    /**
+     * @return array<callable(string): (TwigFunction|false)>
+     */
+    protected function getUndefinedFunctionCallbacks(): array
+    {
+        return [];
+    }
+
+    /**
+     * @return array<callable(string): (TokenParserInterface|false)>
+     */
+    protected function getUndefinedTokenParserCallbacks(): array
+    {
+        return [];
+    }
+
     /**
      * @dataProvider getTests
      *
@@ -222,6 +247,18 @@ abstract class IntegrationTestCase extends TestCase
                 $twig->addFunction($function);
             }
 
+            foreach ($this->getUndefinedFilterCallbacks() as $callback) {
+                $twig->registerUndefinedFilterCallback($callback);
+            }
+
+            foreach ($this->getUndefinedFunctionCallbacks() as $callback) {
+                $twig->registerUndefinedFunctionCallback($callback);
+            }
+
+            foreach ($this->getUndefinedTokenParserCallbacks() as $callback) {
+                $twig->registerUndefinedTokenParserCallback($callback);
+            }
+
             $deprecations = [];
             try {
                 $prevHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) use (&$deprecations, &$prevHandler) {