3.0.0: Fix original nested objects being modified

Author: cloudrac3r

index.js

@@ -25,6 +25,10 @@ function mixin(target, val, key) {
   let obj = target[key];
   if (isObject(val) && isObject(obj)) {
     mixinDeep(obj, val);
+  } else if (!(key in target) && isObject(val)) {
+    // `target` can be mutated by later mixins. Therefore, if we are currently adding an object to `target`,
+    // it could be mutated later. We need to make sure that mutation will not change the original data.
+    target[key] = {...val};
   } else {
     target[key] = val;
   }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "mixin-deep",
   "description": "Deeply mix the properties of objects into the first object. Like merge-deep, but doesn't clone. No dependencies.",
-  "version": "2.0.1",
+  "version": "3.0.0",
   "homepage": "https://github.com/jonschlinkert/mixin-deep",
   "author": "Jon Schlinkert (https://github.com/jonschlinkert)",
   "repository": "jonschlinkert/mixin-deep",