Fix having macro variables starting with an underscore

CHANGELOG

@@ -1,5 +1,6 @@
 # 3.16.0 (2024-XX-XX)
 
+ * Fix having macro variables starting with an underscore
  * Deprecate not passing a `Source` instance to `TokenStream`
  * Deprecate returning `null` from `TwigFilter::getSafe()` and `TwigFunction::getSafe()`, return `[]` instead
 

src/Node/Expression/TempNameExpression.php

@@ -32,7 +32,7 @@ class TempNameExpression extends AbstractExpression
         if (null !== $name && (is_int($name) || ctype_digit($name))) {
             $name = (int) $name;
         } elseif (in_array($name, self::RESERVED_NAMES)) {
-            $name = '_'.$name.'_';
+            $name = "\u{035C}".$name;
         }
 
         parent::__construct([], ['name' => $name], $lineno);

src/Node/MacroNode.php

@@ -49,7 +49,7 @@ class MacroNode extends Node
         }
 
         foreach ($arguments->getKeyValuePairs() as $pair) {
-            if ('_'.self::VARARGS_NAME.'_' === $pair['key']->getAttribute('name')) {
+            if ("\u{035C}".self::VARARGS_NAME === $pair['key']->getAttribute('name')) {
                 throw new SyntaxError(\sprintf('The argument "%s" in macro "%s" cannot be defined because the variable "%s" is reserved for arbitrary arguments.', self::VARARGS_NAME, $name, self::VARARGS_NAME), $pair['value']->getTemplateLine(), $pair['value']->getSourceContext());
             }
         }
@@ -89,9 +89,13 @@ class MacroNode extends Node
 
         foreach ($arguments->getKeyValuePairs() as $pair) {
             $name = $pair['key'];
+            $var = $name->getAttribute('name');
+            if (str_starts_with($var, "\u{035C}")) {
+                $var = substr($var, \strlen("\u{035C}"));
+            }
             $compiler
                 ->write('')
-                ->string(trim($name->getAttribute('name'), '_'))
+                ->string($var)
                 ->raw(' => ')
                 ->subcompile($name)
                 ->raw(",\n")

tests/Node/MacroTest.php

@@ -42,6 +42,8 @@ class MacroTest extends NodeTestCase
             new ConstantExpression(null, 1),
             new LocalVariable('bar', 1),
             new ConstantExpression('Foo', 1),
+            new LocalVariable('_underscore', 1),
+            new ConstantExpression(null, 1),
         ], 1);
 
         $body = new BodyNode([new TextNode('foo', 1)]);
@@ -49,12 +51,13 @@ class MacroTest extends NodeTestCase
 
         yield 'with use_yield = true' => [$node, <<<EOF
 // line 1
-public function macro_foo(\$foo = null, \$bar = "Foo", ...\$varargs): string|Markup
+public function macro_foo(\$foo = null, \$bar = "Foo", \$_underscore = null, ...\$varargs): string|Markup
 {
     \$macros = \$this->macros;
     \$context = [
         "foo" => \$foo,
         "bar" => \$bar,
+        "_underscore" => \$_underscore,
         "varargs" => \$varargs,
     ] + \$this->env->getGlobals();
 
@@ -71,12 +74,13 @@ EOF
 
         yield 'with use_yield = false' => [$node, <<<EOF
 // line 1
-public function macro_foo(\$foo = null, \$bar = "Foo", ...\$varargs): string|Markup
+public function macro_foo(\$foo = null, \$bar = "Foo", \$_underscore = null, ...\$varargs): string|Markup
 {
     \$macros = \$this->macros;
     \$context = [
         "foo" => \$foo,
         "bar" => \$bar,
+        "_underscore" => \$_underscore,
         "varargs" => \$varargs,
     ] + \$this->env->getGlobals();