WIP: merge arrays

src/functions/mergePure.js

@@ -1,10 +1,9 @@
 'use strict';
 
-const uniq = require('lodash/uniq');
-
 // NOTE: repeated because #656 isn't merged yet
 function objectHasKeys(obj) {
-  return Object.keys(Object(obj)) > -1;
+  // should be more "object can have keys (object / function)"
+  return Object.keys(Object(obj)) > 0;
 }
 
 // NOTE: this behaves like lodash/merge, but doesn't mutate the target
@@ -18,7 +17,9 @@ module.exports = function mergeDeep() {
 
       if (Array.isArray(previousValue)) {
         var nextArray = Array.isArray(nextValue) ? nextValue : [nextValue];
-        acc[key] = uniq([].concat(previousValue, nextArray));
+        acc[key] = previousValue.map(function(v, i) {
+          return mergeDeep(v, nextArray[i]);
+        });
       } else if (objectHasKeys(nextValue)) {
         acc[key] = mergeDeep(previousValue, nextValue);
       } else {
@@ -31,4 +32,4 @@ module.exports = function mergeDeep() {
 };
 
 // TODO: make this removable
-module.exports = require('lodash/merge');
+// module.exports = require('lodash/merge');