[TwigComponent] Fix TwigPreLexer edge case

Author: smnandre

src/TwigComponent/src/Twig/TwigPreLexer.php

@@ -263,10 +263,6 @@ private function consumeAttributes(string $componentName): string
      */
     private function consume(string $string): bool
     {
-        if ($string[0] !== $this->input[$this->position]) {
-            return false;
-        }
-
         $stringLength = \strlen($string);
         if (substr($this->input, $this->position, $stringLength) === $string) {
             $this->position += $stringLength;
@@ -405,16 +401,24 @@ private function consumeUntilEndBlock(): string
         $start = $this->position;
 
         $depth = 1;
+        $inComment = false;
         while ($this->position < $this->length) {
-            if ('</twig:block' === substr($this->input, $this->position, 12)) {
+            if ($inComment && '#}' === substr($this->input, $this->position, 2)) {
+                $inComment = false;
+            }
+            if (!$inComment && '{#' === substr($this->input, $this->position, 2)) {
+                $inComment = true;
+            }
+
+            if (!$inComment && '</twig:block>' === substr($this->input, $this->position, 13)) {
                 if (1 === $depth) {
                     break;
                 } else {
                     --$depth;
                 }
             }
 
-            if ('{% endblock %}' === substr($this->input, $this->position, 14)) {
+            if (!$inComment && '{% endblock %}' === substr($this->input, $this->position, 14)) {
                 if (1 === $depth) {
                     // in this case, we want to advanced ALL the way beyond the endblock
                     $this->position += 14;
@@ -424,11 +428,11 @@ private function consumeUntilEndBlock(): string
                 }
             }
 
-            if ('<twig:block' === substr($this->input, $this->position, 11)) {
+            if (!$inComment && '<twig:block' === substr($this->input, $this->position, 11)) {
                 ++$depth;
             }
 
-            if ('{% block' === substr($this->input, $this->position, 8)) {
+            if (!$inComment && '{% block' === substr($this->input, $this->position, 8)) {
                 ++$depth;
             }
 

src/TwigComponent/tests/Unit/TwigPreLexerTest.php

@@ -13,6 +13,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\UX\TwigComponent\Twig\TwigPreLexer;
+use Twig\Error\SyntaxError;
 
 final class TwigPreLexerTest extends TestCase
 {
@@ -25,6 +26,26 @@ public function testPreLex(string $input, string $expectedOutput): void
         $this->assertSame($expectedOutput, $lexer->preLexComponents($input));
     }
 
+    /**
+     * @dataProvider getInvalidSyntaxTests
+     */
+    public function testPreLexThrowsExceptionOnInvalidSyntax(string $input, string $expectedMessage): void
+    {
+        $this->expectException(SyntaxError::class);
+        $this->expectExceptionMessage($expectedMessage);
+
+        $lexer = new TwigPreLexer();
+        $lexer->preLexComponents($input);
+    }
+
+    public static function getInvalidSyntaxTests(): iterable
+    {
+        yield 'component_with_unclosed_block' => [
+            '<twig:foo name="bar">{% block a %}</twig:foo>',
+            'Expected closing tag "</twig:foo>" not found at line 1.',
+        ];
+    }
+
     public static function getLexTests(): iterable
     {
         yield 'simple_component' => [
@@ -62,6 +83,11 @@ public static function getLexTests(): iterable
             'Hello {% block foo_block %}Foo{% endblock %}{{ component(\'foo\') }}{% block bar_block %}Bar{% endblock %}',
         ];
 
+        yield 'component_with_commented_block' => [
+            '<twig:foo name="bar">{#  {% block baz %}#}</twig:foo>',
+            '{% component \'foo\' with { name: \'bar\' } %}{#  {% block baz %}#}{% endcomponent %}',
+        ];
+
         yield 'component_with_component_inside_block' => [
             '<twig:foo><twig:block name="foo_block"><twig:bar /></twig:block></twig:foo>',
             '{% component \'foo\' %}{% block foo_block %}{{ component(\'bar\') }}{% endblock %}{% endcomponent %}',