+ preserveComments option to Minify_Javascript (default true), test case, and doc comments

lib/Minify/Javascript.php

@@ -13,8 +13,62 @@ require dirname(__FILE__) . '/3rd_party/jsmin.php';
  * @author Stephen Clay <steve@mrclay.org>
  */
 class Minify_Javascript {
+
+    /**
+     * Minify a Javascript string
+     * 
+     * @param string $js input javascript
+     * 
+     * @param array $options available options:
+     * 
+     * 'preserveComments': (default true) multi-line comments that begin
+     * with "/*!" will be preserved with newlines before and after to
+     * preserve readability.
+     * 
+     * @return string 
+     */
     public static function minify($js, $options = array()) {
-        return trim(JSMin::minify($js));
+        if (isset($options['preserveComments']) 
+            && !$options['preserveComments']) {
+            return trim(JSMin::minify($js));    
+        }
+        $ret = '';
+        while (1) {
+            list($beforeComment, $comment, $afterComment)
+                = self::_nextYuiComment($js);
+            $ret .= trim(JSMin::minify($beforeComment));
+            if (false === $comment) {
+                break;
+            }
+            $ret .= $comment;
+            $js = $afterComment;
+        }
+        return $ret;
+    }
+    
+    /**
+     * Extract comments that YUI Compressor preserves.
+     * 
+     * @param string $js input
+     * 
+     * @return array 3 elements are returned. If a YUI comment is found, the
+     * 2nd element is the comment and the 1st and 2nd are the surrounding
+     * strings. If no comment is found, the entire string is returned as the 1st
+     * element and the other two are false.
+     */
+    private static function _nextYuiComment($js)
+    {
+        return (
+            (false !== ($start = strpos($js, '/*!')))
+            && (false !== ($end = strpos($js, '*/')))
+            && ($start < $end)
+        )
+            ? array(
+                substr($js, 0, $start)
+                ,"\n/*" . substr($js, $start + 3, $end - $start - 1) . "\n"
+                ,substr($js, -(strlen($js) - $end - 2))
+            )
+            : array($js, false, false);
     }
 }