1 files changed, 33 insertions, 0 deletions
diff --git a/node_modules/csso/lib/compressor/compress/Url.js b/node_modules/csso/lib/compressor/compress/Url.js
new file mode 100644
index 00000000..040a3590
--- /dev/null
+++ b/node_modules/csso/lib/compressor/compress/Url.js
@@ -0,0 +1,33 @@
+var UNICODE = '\\\\[0-9a-f]{1,6}(\\r\\n|[ \\n\\r\\t\\f])?';
+var ESCAPE = '(' + UNICODE + '|\\\\[^\\n\\r\\f0-9a-fA-F])';
+var NONPRINTABLE = '\u0000\u0008\u000b\u000e-\u001f\u007f';
+var SAFE_URL = new RegExp('^(' + ESCAPE + '|[^\"\'\\(\\)\\\\\\s' + NONPRINTABLE + '])*$', 'i');
+
+module.exports = function(node) {
+    var value = node.value;
+
+    if (value.type !== 'String') {
+        return;
+    }
+
+    var quote = value.value[0];
+    var url = value.value.substr(1, value.value.length - 2);
+
+    // convert `\\` to `/`
+    url = url.replace(/\\\\/g, '/');
+
+    // remove quotes when safe
+    // https://www.w3.org/TR/css-syntax-3/#url-unquoted-diagram
+    if (SAFE_URL.test(url)) {
+        node.value = {
+            type: 'Raw',
+            info: node.value.info,
+            value: url
+        };
+    } else {
+        // use double quotes if string has no double quotes
+        // otherwise use original quotes
+        // TODO: make better quote type selection
+        node.value.value = url.indexOf('"') === -1 ? '"' + url + '"' : quote + url + quote;
+    }
+};