[Html] add strip_tags function

src/Psl/Html/encode.php

@@ -20,6 +20,8 @@ use const ENT_QUOTES;
  *
  * @throws Exception\InvariantViolationException If $encoding is invalid.
  *
+ * @psalm-taint-escape html
+ *
  * @psalm-pure
  */
 function encode(string $html, bool $double_encoding = true, ?string $encoding = null): string

src/Psl/Html/encode_special_characters.php

@@ -22,6 +22,8 @@ use const ENT_SUBSTITUTE;
  *
  * @throws Exception\InvariantViolationException If $encoding is invalid.
  *
+ * @psalm-taint-escape html
+ *
  * @psalm-pure
  */
 function encode_special_characters(string $html, bool $double_encoding = true, ?string $encoding = null): string

src/Psl/Html/strip_tags.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psl\Html;
+
+use function strip_tags as php_strip_tags;
+
+/**
+ * Strip HTML and PHP tags from a string.
+ *
+ * @param list<string> $allowed_tags tags which should not be stripped.
+ *
+ * @psalm-pure
+ */
+function strip_tags(string $html, array $allowed_tags = []): string
+{
+    /**
+     * @psalm-suppress InvalidArgument
+     *
+     * @link https://github.com/vimeo/psalm/issues/5330
+     */
+    return php_strip_tags($html, $allowed_tags);
+}

src/Psl/Internal/Loader.php

@@ -464,6 +464,7 @@ final class Loader
         'Psl\Html\encode_special_characters',
         'Psl\Html\decode',
         'Psl\Html\decode_special_characters',
+        'Psl\Html\strip_tags',
     ];
 
     public const INTERFACES = [

tests/Psl/Html/StripTagsTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psl\Tests\Html;
+
+use PHPUnit\Framework\TestCase;
+use Psl\Html;
+
+final class StripTagsTest extends TestCase
+{
+    /**
+     * @dataProvider provideData
+     */
+    public function testEncode(string $expected, string $html, array $allowed_tags): void
+    {
+        static::assertSame($expected, Html\strip_tags($html, $allowed_tags));
+    }
+
+    public function provideData(): iterable
+    {
+        yield ['hello', 'hello', []];
+        yield ['hello', '<p>hello</p>', []];
+        yield ['<p>hello</p>', '<p>hello</p>', ['p']];
+        yield ['<p>hello</p>', '<p>hello</p>', ['p', 'span']];
+        yield ['hello, <span>world!</span>', '<p>hello, <span>world!</span></p>', ['span']];
+        yield ['<p>hello, world!</p>', '<p>hello, <span>world!</span></p>', ['p']];
+        yield ['hello, world!', '<p>hello, <span>world!</span></p>', []];
+    }
+}