Use jsesc to escape special characters.

Similar to webpack-contrib/raw-loader#36 we can
use jsesc here to deal with special characters in general.

Author: bmeurer

index.js

@@ -1,11 +1,12 @@
+const jsesc = require('jsesc');
+
 module.exports = function (source) {
   if (this.cacheable) this.cacheable();
 
   var value = typeof source === "string" ? JSON.parse(source) : source;
 
-  value = JSON.stringify(value)
-    .replace(/\u2028/g, '\\u2028')
-    .replace(/\u2029/g, '\\u2029');
+  value = JSON.stringify(value);
+  value = jsesc(value);
 
   return `module.exports = ${value}`;
 }

package-lock.json

@@ -13,5 +13,8 @@
   "repository": {
     "type": "git",
     "url": "https://github.com/webpack/json-loader.git"
+  },
+  "dependencies": {
+    "jsesc": "^2.5.1"
   }
 }