Refactor and introduce deepMerge

lib/utils.js

@@ -260,6 +260,32 @@ function merge(/* obj1, obj2, obj3, ... */) {
   return result;
 }
 
+/**
+ * Function equal to merge with the difference being that no reference
+ * to original objects is kept.
+ *
+ * @see merge
+ * @param {Object} obj1 Object to merge
+ * @returns {Object} Result of all merge properties
+ */
+function deepMerge(/* obj1, obj2, obj3, ... */) {
+  var result = {};
+  function assignValue(val, key) {
+    if (typeof result[key] === 'object' && typeof val === 'object') {
+      result[key] = merge(result[key], val);
+    } else if (typeof val === 'object') {
+      result[key] = merge({}, val);
+    } else {
+      result[key] = val;
+    }
+  }
+
+  for (var i = 0, l = arguments.length; i < l; i++) {
+    forEach(arguments[i], assignValue);
+  }
+  return result;
+}
+
 /**
  * Extends object a by mutably adding to it the properties of object b.
  *
@@ -279,43 +305,6 @@ function extend(a, b, thisArg) {
   return a;
 }
 
-
-/**
- * Config-specific merge-function which creates a new config-object
- * based on given defaults and instance config.
- *
- * @param {Object} defaults Defaults
- * @param {Object} instanceConfig Instance-specific config
- * @returns {Object} New object resulting from merging instanceConfig to defaults
- */
-function mergeConfig(defaults, instanceConfig) {
-  instanceConfig = instanceConfig || {};
-  var config = {};
-  forEach(['url', 'method', 'params', 'data'], function valueFromInstanceConfig(prop) {
-    config[prop] = instanceConfig[prop];
-  });
-  forEach(['headers', 'auth', 'proxy'], function mergeInstanceConfigWithDefaults(prop) {
-    if (!isUndefined(instanceConfig[prop])) {
-      if (isObject(instanceConfig[prop])) {
-        config[prop] = merge(defaults[prop], instanceConfig[prop]);
-      } else {
-        config[prop] = instanceConfig[prop];
-      }
-    } else if (!isUndefined(defaults[prop])) {
-      config[prop] = JSON.parse(JSON.stringify(defaults[prop]));
-    }
-  });
-  forEach([
-    'baseURL', 'transformRequest', 'transformResponse', 'paramsSerializer',
-    'timeout', 'withCredentials', 'adapter', 'responseType', 'xsrfCookieName',
-    'xsrfHeaderName', 'onUploadProgress', 'onDownloadProgress', 'maxContentLength',
-    'validateStatus', 'maxRedirects', 'httpAgent', 'httpsAgent', 'cancelToken'
-  ], function defaultToInstanceConfig(prop) {
-    config[prop] = isUndefined(instanceConfig[prop]) ? defaults[prop] : instanceConfig[prop];
-  });
-  return config;
-}
-
 module.exports = {
   isArray: isArray,
   isArrayBuffer: isArrayBuffer,
@@ -335,7 +324,7 @@ module.exports = {
   isStandardBrowserEnv: isStandardBrowserEnv,
   forEach: forEach,
   merge: merge,
+  deepMerge: deepMerge,
   extend: extend,
-  trim: trim,
-  mergeConfig: mergeConfig
+  trim: trim
 };