fix: added file property to the generated sourcemap (#1190)

Author: Ross-Esmond

lib/parser.js

@@ -38,7 +38,10 @@ module.exports = (content, filename, needMap, sourceRoot, needCSSMap) => {
 }
 
 function generateSourceMap (filename, source, generated, sourceRoot) {
-  const map = new SourceMapGenerator({ sourceRoot })
+  const map = new SourceMapGenerator({
+    file: filename,
+    sourceRoot
+  })
   map.setSourceContent(filename, source)
   generated.split(splitRE).forEach((line, index) => {
     if (!emptyRE.test(line)) {