Implement the rewriteCssUrls function.

Author: tamaspap

index.js

@@ -0,0 +1,51 @@
+'use strict';
+
+module.exports = rewriteCssUrls;
+
+//////////////////////////////
+
+/**
+ * Rewrite the urls in a css using the provided function.
+ *
+ * @param css
+ * @param fn
+ * @returns {*}
+ */
+function rewriteCssUrls(css, fn) {
+  var replacePairs = replacePairsForResources(css, fn).concat(replacePairsForImports(css, fn));
+  replacePairs.forEach(function(replacePair) {
+    css = css.replace(replacePair[0], replacePair[1]);
+  });
+
+  return css;
+}
+
+/**
+ * Find the replace pairs for @import tags without the `url()` tag.
+ *
+ * @param css
+ * @param fn
+ * @returns {Array}
+ */
+function replacePairsForImports(css, fn) {
+  var matches = css.match(/@import(\s+)('|")(.+?)('|")/ig) || [];
+  return matches.map(function(match) {
+    var url = match.replace(/@import|'|"/gi, '').trim();
+    return [match, '@import url("' + fn(url) + '")'];
+  });
+}
+
+/**
+ * Find the replace pairs for resources using the `url()` tag.
+ *
+ * @param css
+ * @param fn
+ * @returns {Array}
+ */
+function replacePairsForResources(css, fn) {
+  var matches = css.match(/url\(.+?\)/ig) || [];
+  return matches.map(function(match) {
+    var url = match.replace(/url\(|\)|'|"/gi, '').trim();
+    return [match, 'url("' + fn(url) + '")'];
+  });
+}