Merge pull request #129 from thephpleague/fix-autolinks

Only autolink if href meets CommonMark spec

CHANGELOG.md

@@ -4,6 +4,11 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 
 ## [Unreleased][unreleased]
 
+## [4.4.1]
+
+### Fixed
+ - Fixed autolinking of invalid URLs (#129)
+
 ## [4.4.0]
 
 ### Added
@@ -183,7 +188,8 @@ not ideally set, so this releases fixes that. Moving forwards this should reduce
 ### Added
  - Initial release
 
-[unreleased]: https://github.com/thephpleague/html-to-markdown/compare/4.4.0...master
+[unreleased]: https://github.com/thephpleague/html-to-markdown/compare/4.4.1...master
+[4.4.1]: https://github.com/thephpleague/html-to-markdown/compare/4.4.0...4.4.1
 [4.4.0]: https://github.com/thephpleague/html-to-markdown/compare/4.3.1...4.4.0
 [4.3.1]: https://github.com/thephpleague/html-to-markdown/compare/4.3.0...4.3.1
 [4.3.0]: https://github.com/thephpleague/html-to-markdown/compare/4.2.2...4.3.0

src/Converter/LinkConverter.php

@@ -19,7 +19,7 @@ public function convert(ElementInterface $element)
 
         if ($title !== '') {
             $markdown = '[' . $text . '](' . $href . ' "' . $title . '")';
-        } elseif ($href === $text) {
+        } elseif ($href === $text && $this->isValidAutolink($href)) {
             $markdown = '<' . $href . '>';
         } else {
             $markdown = '[' . $text . '](' . $href . ')';
@@ -39,4 +39,14 @@ public function getSupportedTags()
     {
         return array('a');
     }
+
+    /**
+     * @param string $href
+     *
+     * @return bool
+     */
+    private function isValidAutolink($href)
+    {
+        return preg_match('/^[A-Za-z][A-Za-z0-9.+-]{1,31}:[^<>\x00-\x20]*/i', $href) === 1;
+    }
 }

tests/HtmlConverterTest.php

@@ -107,6 +107,12 @@ public function test_anchor()
         $this->html_gives_markdown('<a href="">Test</a>', '<a href="">Test</a>');
         $this->html_gives_markdown('<a href="#nerd" title="Title">Test</a>', '[Test](#nerd "Title")');
         $this->html_gives_markdown('<a href="#nerd">Test</a>', '[Test](#nerd)');
+
+        // Autolinking
+        $this->html_gives_markdown('<a href="test">test</a>', '[test](test)');
+        $this->html_gives_markdown('<a href="google.com">google.com</a>', '[google.com](google.com)');
+        $this->html_gives_markdown('<a href="https://www.google.com">https://www.google.com</a>', '<https://www.google.com>');
+        $this->html_gives_markdown('<a href="ftp://files.example.com">ftp://files.example.com</a>', '<ftp://files.example.com>');
     }
 
     public function test_horizontal_rule()