fix: if locals not json

Author: Scrum

lib/index.js

@@ -25,8 +25,7 @@ module.exports = (options = {}) => {
       if (src) {
         src = path.resolve(options.root, src);
         source = fs.readFileSync(src, options.encoding);
-
-        if (locals) {
+        if (locals && locals.includes(':')) {
           locals = JSON.parse(locals);
           const result = posthtml()
             .use(expressions({locals}))