fix(index): 'Cannot create property prev on boolean false' (options.sourceMap)

Author: michael-ciniawsky

lib/index.js

@@ -69,14 +69,14 @@ module.exports = function loader (css, map) {
       : rc.ctx.options = {}
   }
 
-  delete options.config
-
   const sourceMap = options.sourceMap
 
-  delete options.sourceMap
-
   Promise.resolve().then(() => {
-    if (Object.keys(options).length !== 0) {
+    if (
+      Object.keys(options).length !== 0 ||
+      ((rc || sourceMap) && Object.keys(options).length > 1) ||
+      ((rc && sourceMap) && Object.keys(options).length > 2)
+    ) {
       return parseOptions.call(this, options)
     }