Fix bugs with toPx() function

Author: ericf

index.js

@@ -19,7 +19,7 @@ function match(mediaQuery, values) {
 var RE_MEDIA_QUERY   = /(?:(only|not)?\s*([^\s\(\)]+)\s*and\s*)?(.+)?/i,
     RE_MQ_EXPRESSION = /\(\s*([^\s\:\)]+)\s*(?:\:\s*([^\s\)]+))?\s*\)/,
     RE_MQ_FEATURE    = /^(?:(min|max)-)?(.+)/,
-    RE_LENGTH_VALUE  = /(\d+)(em|rem|px|cm|mm|in|pt|pc)?/;
+    RE_LENGTH_UNIT   = /(em|rem|px|cm|mm|in|pt|pc)?$/;
 
 function parseQuery(mediaQuery) {
     return mediaQuery.split(',').map(function (query) {
@@ -53,25 +53,17 @@ function parseQuery(mediaQuery) {
 }
 
 function toPx(length) {
-    var captures = String(length).match(RE_LENGTH_VALUE),
-        value    = Number(captures[1]),
-        units    = captures[2];
+    var value = parseFloat(length),
+        units = String(length).match(RE_LENGTH_UNIT)[1];
 
     switch (units) {
-        case 'em':
-        case 'rem':
-            return value * 16;
-        case 'cm':
-            return value * 96 / 2.54;
-        case 'mm':
-            return value * 96 / 2.54 / 10;
-        case 'in':
-            return value * 96;
-        case 'pt':
-            return value * 72;
-        case 'pc':
-            return value * 72 / 12;
-        default:
-            return value;
+        case 'em' : return value * 16;
+        case 'rem': return value * 16;
+        case 'cm' : return value * 96 / 2.54;
+        case 'mm' : return value * 96 / 2.54 / 10;
+        case 'in' : return value * 96;
+        case 'pt' : return value * 72;
+        case 'pc' : return value * 72 / 12;
+        default   : return value;
     }
 }