diff --git a/tests/URLDetectionTest.php b/tests/URLDetectionTest.php
new file mode 100644
index 0000000000..f35b03eaf2
--- /dev/null
+++ b/tests/URLDetectionTest.php
@@ -0,0 +1,189 @@
+<?php
+
+if (isset($_SERVER) && array_key_exists('REQUEST_METHOD', $_SERVER)) {
+    print "This script must be run from the command line\n";
+    exit();
+}
+
+define('INSTALLDIR', realpath(dirname(__FILE__) . '/..'));
+define('LACONICA', true);
+
+require_once INSTALLDIR . '/lib/common.php';
+
+class URLDetectionTest extends PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider provider
+     *
+     */
+    public function testProduction($content, $expected)
+    {
+        $rendered = common_render_text($content);
+        $this->assertEquals($expected, $rendered);
+    }
+
+    static public function provider()
+    {
+        return array(
+                     array('example',
+                           'example'),
+                     array('http://example',
+                           'http://example'),
+                     array('http://example/',
+                           'http://example/'),
+                     array('http://example/path',
+                           'http://example/path'),
+                     array('http://example.com',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>'),
+                     array('https://example.com',
+                           '<a href="https://example.com" class="extlink">https://example.com</a>'),
+                     array('ftp://example.com',
+                           '<a href="ftp://example.com" class="extlink">ftp://example.com</a>'),
+                     array('ftps://example.com',
+                           '<a href="ftps://example.com" class="extlink">ftps://example.com</a>'),
+                     array('http://user@example.com',
+                           '<a href="http://user@example.com" class="extlink">http://user@example.com</a>'),
+                     array('http://user:pass@example.com',
+                           '<a href="http://user:pass@example.com" class="extlink">http://user:pass@example.com</a>'),
+                     array('http://example.com:8080',
+                           '<a href="http://example.com:8080" class="extlink">http://example.com:8080</a>'),
+                     array('http://www.example.com',
+                           '<a href="http://www.example.com" class="extlink">http://www.example.com</a>'),
+                     array('http://example.com/',
+                           '<a href="http://example.com/" class="extlink">http://example.com/</a>'),
+                     array('http://example.com/path',
+                           '<a href="http://example.com/path" class="extlink">http://example.com/path</a>'),
+                     array('http://example.com/path.html',
+                           '<a href="http://example.com/path.html" class="extlink">http://example.com/path.html</a>'),
+                     array('http://example.com/path.html#fragment',
+                           '<a href="http://example.com/path.html#fragment" class="extlink">http://example.com/path.html#fragment</a>'),
+                     array('http://example.com/path.php?foo=bar&bar=foo',
+                           '<a href="http://example.com/path.php?foo=bar&bar=foo" class="extlink">http://example.com/path.php?foo=bar&bar=foo</a>'),
+                     array('http://müllärör.de',
+                           '<a href="http://müllärör.de" class="extlink">http://müllärör.de</a>'),
+                     array('http://ﺱﺲﺷ.com',
+                           '<a href="http://ﺱﺲﺷ.com" class="extlink">http://ﺱﺲﺷ.com</a>'),
+                     array('http://сделаткартинки.com',
+                           '<a href="http://сделаткартинки.com" class="extlink">http://сделаткартинки.com</a>'),
+                     array('http://tūdaliņ.lv',
+                           '<a href="http://tūdaliņ.lv" class="extlink">http://tūdaliņ.lv</a>'),
+                     array('http://brændendekærlighed.com',
+                           '<a href="http://brændendekærlighed.com" class="extlink">http://brændendekærlighed.com</a>'),
+                     array('http://あーるいん.com',
+                           '<a href="http://あーるいん.com" class="extlink">http://あーるいん.com</a>'),
+                     array('http://예비교사.com',
+                           '<a href="http://예비교사.com" class="extlink">http://예비교사.com</a>'),
+                     array('http://example.com.',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>.'),
+                     array('http://example.com?',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>?'),
+                     array('http://example.com!',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>!'),
+                     array('http://example.com,',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>,'),
+                     array('http://example.com;',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>;'),
+                     array('http://example.com:',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>:'),
+                     array('\'http://example.com\'',
+                           '\'<a href="http://example.com" class="extlink">http://example.com</a>\''),
+                     array('"http://example.com"',
+                           '"<a href="http://example.com" class="extlink">http://example.com</a>"'),
+                     array('http://example.com
',
+                           '<a href="http://example.com" class="extlink">http://example.com</a>'),
+                     array('(http://example.com)',
+                           '(<a href="http://example.com" class="extlink">http://example.com</a>)'),
+                     array('[http://example.com]',
+                           '[<a href="http://example.com" class="extlink">http://example.com</a>]'),
+                     array('<http://example.com>',
+                           '<<a href="http://example.com" class="extlink">http://example.com</a>>'),
+                     array('http://example.com/path/(foo)/bar',
+                           '<a href="http://example.com/path/(foo)/bar" class="extlink">http://example.com/path/(foo)/bar</a>'),
+                     array('http://example.com/path/[foo]/bar',
+                           '<a href="http://example.com/path/[foo]/bar" class="extlink">http://example.com/path/[foo]/bar</a>'),
+                     array('http://example.com/path/foo/(bar)',
+                           '<a href="http://example.com/path/foo/(bar)" class="extlink">http://example.com/path/foo/(bar)</a>'),
+                     array('http://example.com/path/foo/[bar]',
+                           '<a href="http://example.com/path/foo/[bar]" class="extlink">http://example.com/path/foo/[bar]</a>'),
+                     array('Hey, check out my cool site http://example.com okay?',
+                           'Hey, check out my cool site <a href="http://example.com" class="extlink">http://example.com</a> okay?'),
+                     array('What about parens (e.g. http://example.com/path/foo/(bar))?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">http://example.com/path/foo/(bar)</a>)?'),
+                     array('What about parens (e.g. http://example.com/path/foo/(bar)?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">http://example.com/path/foo/(bar)</a>?'),
+                     array('What about parens (e.g. http://example.com/path/foo/(bar).)?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">http://example.com/path/foo/(bar)</a>.)?'),
+                     array('What about parens (e.g. http://example.com/path/(foo,bar)?',
+                           'What about parens (e.g. <a href="http://example.com/path/(foo,bar)" class="extlink">http://example.com/path/(foo,bar)</a>?'),
+                     array('Unbalanced too (e.g. http://example.com/path/((((foo)/bar)?',
+                           'Unbalanced too (e.g. <a href="http://example.com/path/((((foo)/bar)" class="extlink">http://example.com/path/((((foo)/bar)</a>?'),
+                     array('Unbalanced too (e.g. http://example.com/path/(foo))))/bar)?',
+                           'Unbalanced too (e.g. <a href="http://example.com/path/(foo))))/bar" class="extlink">http://example.com/path/(foo))))/bar</a>)?'),
+                     array('Unbalanced too (e.g. http://example.com/path/foo/((((bar)?',
+                           'Unbalanced too (e.g. <a href="http://example.com/path/foo/((((bar)" class="extlink">http://example.com/path/foo/((((bar)</a>?'),
+                     array('Unbalanced too (e.g. http://example.com/path/foo/(bar))))?',
+                           'Unbalanced too (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">http://example.com/path/foo/(bar)</a>)))?'),
+                     array('example.com',
+                           '<a href="http://example.com" class="extlink">example.com</a>'),
+                     array('example.org',
+                           '<a href="http://example.org" class="extlink">example.org</a>'),
+                     array('example.co.uk',
+                           '<a href="http://example.co.uk" class="extlink">example.co.uk</a>'),
+                     array('www.example.co.uk',
+                           '<a href="http://www.example.co.uk" class="extlink">www.example.co.uk</a>'),
+                     array('farm1.images.example.co.uk',
+                           '<a href="http://farm1.images.example.co.uk" class="extlink">farm1.images.example.co.uk</a>'),
+                     array('example.museum',
+                           '<a href="http://example.museum" class="extlink">example.museum</a>'),
+                     array('example.travel',
+                           '<a href="http://example.travel" class="extlink">example.travel</a>'),
+                     array('example.com.',
+                           '<a href="http://example.com" class="extlink">example.com</a>.'),
+                     array('example.com?',
+                           '<a href="http://example.com" class="extlink">example.com</a>?'),
+                     array('example.com!',
+                           '<a href="http://example.com" class="extlink">example.com</a>!'),
+                     array('example.com,',
+                           '<a href="http://example.com" class="extlink">example.com</a>,'),
+                     array('example.com;',
+                           '<a href="http://example.com" class="extlink">example.com</a>;'),
+                     array('example.com:',
+                           '<a href="http://example.com" class="extlink">example.com</a>:'),
+                     array('\'example.com\'',
+                           '\'<a href="http://example.com" class="extlink">example.com</a>\''),
+                     array('"example.com"',
+                           '"<a href="http://example.com" class="extlink">example.com</a>"'),
+                     array('example.com
',
+                           '<a href="http://example.com" class="extlink">example.com</a>'),
+                     array('(example.com)',
+                           '(<a href="http://example.com" class="extlink">example.com</a>)'),
+                     array('[example.com]',
+                           '[<a href="http://example.com" class="extlink">example.com</a>]'),
+                     array('<example.com>',
+                           '<<a href="http://example.com" class="extlink">example.com</a>>'),
+                     array('Hey, check out my cool site example.com okay?',
+                           'Hey, check out my cool site <a href="http://example.com" class="extlink">example.com</a> okay?'),
+                     array('Hey, check out my cool site example.com.I made it.',
+                           'Hey, check out my cool site <a href="http://example.com" class="extlink">example.com</a>.I made it.'),
+                     array('Hey, check out my cool site example.com.Funny thing...',
+                           'Hey, check out my cool site <a href="http://example.com" class="extlink">example.com</a>.Funny thing...'),
+                     array('Hey, check out my cool site example.com.You will love it.',
+                           'Hey, check out my cool site <a href="http://example.com" class="extlink">example.com</a>.You will love it.'),
+                     array('What about parens (e.g. example.com/path/foo/(bar))?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">example.com/path/foo/(bar)</a>)?'),
+                     array('What about parens (e.g. example.com/path/foo/(bar)?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">example.com/path/foo/(bar)</a>?'),
+                     array('What about parens (e.g. example.com/path/foo/(bar).)?',
+                           'What about parens (e.g. <a href="http://example.com/path/foo/(bar)" class="extlink">example.com/path/foo/(bar)</a>.)?'),
+                     array('What about parens (e.g. example.com/path/(foo,bar)?',
+                           'What about parens (e.g. <a href="http://example.com/path/(foo,bar)" class="extlink">example.com/path/(foo,bar)</a>?'),
+                     array('file.ext',
+                           'file.ext'),
+                     array('file.html',
+                           'file.html'),
+                     array('file.php',
+                           'file.php')
+                     );
+    }
+}
+