Fix PHP tags in strings breaking Volt template rendering

src/Precompilers/ExtractTemplate.php

@@ -6,6 +6,7 @@
 use Livewire\Volt\Exceptions\ReturnNewClassExecutionEndingException;
 use Livewire\Volt\MountedDirectories;
 use Livewire\Volt\Volt;
+use PhpToken;
 
 class ExtractTemplate
 {
@@ -48,9 +49,21 @@ protected function shouldExtractTemplate(string $template): bool
      */
     protected function html(string $template): string
     {
-        $template = trim(preg_replace('/<\?php\s*(.*?)\s*\?>/s', '', $template));
+        $html = '';
+        $inPhp = false;
 
-        return str($template)->beforeLast('<?php')->trim()->value();
+        foreach (PhpToken::tokenize($template) as $token) {
+            if ($token->is(T_OPEN_TAG)) {
+                $inPhp = true;
+            } elseif ($inPhp && $token->is(T_CLOSE_TAG)) {
+                $inPhp = false;
+                $html .= substr($token->text, 2);
+            } elseif (! $inPhp) {
+                $html .= $token->text;
+            }
+        }
+
+        return trim($html);
     }
 
     /**

tests/Feature/FunctionalComponentTest.php

@@ -939,3 +939,11 @@ public function render()
         ->call('increment')
         ->assertSet('counter', 3);
 });
+
+it('renders PHP tags in state strings before and after an update', function () {
+    Volt::test('php-tags-in-strings')
+        ->assertSee('Example of ?> causing problems')
+        ->assertSee('PHP starts with <?php and ends with ?>')
+        ->call('update')
+        ->assertSee('Updated text containing ?>');
+});

tests/Feature/resources/views/functional-api/php-tags-in-strings.blade.php

@@ -0,0 +1,17 @@
+<?php
+
+use function Livewire\Volt\state;
+
+state([
+    'title' => 'Example of ?> causing problems',
+    'message' => 'PHP starts with <?php and ends with ?>',
+]);
+
+$update = fn () => $this->title = 'Updated text containing ?>';
+?>
+
+<div>
+    <h1>{{ $title }}</h1>
+    <p>{{ $message }}</p>
+    <button wire:click="update">Update text</button>
+</div>

tests/Unit/Precompilers/ExtractTemplateTest.php

@@ -418,3 +418,65 @@ function something() use () {
 
     expect(trim($result))->toBe($expected);
 })->with($conflictsDataset);
+
+it('ignores PHP tags inside strings when extracting the template', function () {
+    $template = <<<'HTML'
+        <?php
+
+        use function Livewire\Volt\state;
+
+        state([
+            'title' => 'Example of ?> causing problems',
+            'message' => 'PHP starts with <?php and ends with ?>',
+        ]);
+
+        ?>
+
+        <div>
+            <h1>{{ $title }}</h1>
+            <p>{{ $message }}</p>
+        </div>
+        HTML;
+
+    $expected = <<<'HTML'
+        <div>
+            <h1>{{ $title }}</h1>
+            <p>{{ $message }}</p>
+        </div>
+        HTML;
+
+    expect($this->precompiler->__invoke($template))->toBe($expected);
+});
+
+it('ignores PHP tags inside comments and multiline strings', function () {
+    $template = <<<'HTML'
+        <?php
+
+        /* A comment containing ?> and <?php */
+        $message = <<<'TEXT'
+        PHP starts with <?php and ends with ?>
+        TEXT;
+
+        ?>
+
+        <div>{{ $message }}</div>
+        HTML;
+
+    expect($this->precompiler->__invoke($template))->toBe('<div>{{ $message }}</div>');
+});
+
+it('preserves short echo tags in the template', function () {
+    $template = <<<'HTML'
+        <?php
+
+        use function Livewire\Volt\state;
+
+        state('name');
+
+        ?>
+
+        <div><?= $name ?></div>
+        HTML;
+
+    expect($this->precompiler->__invoke($template))->toBe('<div><?= $name ?></div>');
+});