Supports localhost #6

src/Autolink.php

@@ -85,16 +85,18 @@ public function __construct(array $options = [], array $schemes = [])
     public function convert(string $text, array $attribs = []): string
     {
         $linkNoScheme = $this->getLinkNoScheme();
+        $staticDomains = '|localhost';
 
         if ($linkNoScheme) {
             $schemeRegex = "[(%s)\:\/\/@]*";
+            $staticDomains = '';
         } else {
             $schemeRegex = "(%s)\:\/\/";
         }
 
         $schemeRegex = sprintf($schemeRegex, $this->getSchemes(true));
 
-        $regex = '/(([a-zA-Z]*=")*' . $schemeRegex . "[\-\p{L}\p{N}\p{M}]+\.[\p{L}\p{M}]{2,}([\/\p{L}\p{N}\p{M}\-._~:?#\[\]@!$&'()*+,;=%\">]*)?)/u";
+        $regex = '/(([a-zA-Z]*=")*' . $schemeRegex . "([\-\p{L}\p{N}\p{M}]+\.[\p{L}\p{M}]{2,}$staticDomains)([\/\p{L}\p{N}\p{M}\-._~:?#\[\]@!$&'()*+,;=%\">]*)?)/u";
 
         return preg_replace_callback(
             $regex,

test/AutolinkTest.php

@@ -407,6 +407,38 @@ public function testIgnoreTrailingDot(): void
         );
     }
 
+    public function testLocalhost(): void
+    {
+        $txt = 'Link to http://localhost with some text.';
+
+        $html = $this->instance->convert($txt);
+
+        assertEquals(
+            'Link to <a href="http://localhost">http://localhost</a> with some text.',
+            $html,
+        );
+
+        $txt = 'Link to http://localhost.';
+
+        $html = $this->instance->convert($txt);
+
+        assertEquals(
+            'Link to <a href="http://localhost">http://localhost</a>.',
+            $html,
+        );
+
+        // Localhost without scheme should be ignored.
+        $txt = 'Link to localhost.';
+
+        $this->instance->linkNoScheme(true);
+        $html = $this->instance->convert($txt);
+
+        assertEquals(
+            'Link to localhost.',
+            $html,
+        );
+    }
+
     /**
      * urlProvider
      *