Merge pull request #90 from pirxpilot/fix-sourcemap-filename

fix `input.js` file entries in source maps

Author: goto-bus-stop

index.js

@@ -34,7 +34,8 @@ module.exports = function (file, opts) {
             vars: vars,
             varModules: { path: path },
             parserOpts: opts && opts.parserOpts,
-            sourceMap: opts && (opts.sourceMap || opts._flags && opts._flags.debug)
+            sourceMap: opts && (opts.sourceMap || opts._flags && opts._flags.debug),
+            inputFilename: file
         }
     );
     return sm;