Bump to v4.1.0.

_baseMerge.js

@@ -0,0 +1,44 @@
+var Stack = require('./_Stack'),
+    arrayEach = require('./_arrayEach'),
+    assignMergeValue = require('./_assignMergeValue'),
+    baseMergeDeep = require('./_baseMergeDeep'),
+    isArray = require('./isArray'),
+    isObject = require('./isObject'),
+    isTypedArray = require('./isTypedArray'),
+    keysIn = require('./keysIn');
+
+/**
+ * The base implementation of `_.merge` without support for multiple sources.
+ *
+ * @private
+ * @param {Object} object The destination object.
+ * @param {Object} source The source object.
+ * @param {number} srcIndex The index of `source`.
+ * @param {Function} [customizer] The function to customize merged values.
+ * @param {Object} [stack] Tracks traversed source values and their merged counterparts.
+ */
+function baseMerge(object, source, srcIndex, customizer, stack) {
+  if (object === source) {
+    return;
+  }
+  var props = (isArray(source) || isTypedArray(source)) ? undefined : keysIn(source);
+  arrayEach(props || source, function(srcValue, key) {
+    if (props) {
+      key = srcValue;
+      srcValue = source[key];
+    }
+    if (isObject(srcValue)) {
+      stack || (stack = new Stack);
+      baseMergeDeep(object, source, key, srcIndex, baseMerge, customizer, stack);
+    }
+    else {
+      var newValue = customizer ? customizer(object[key], srcValue, (key + ''), object, source, stack) : undefined;
+      if (newValue === undefined) {
+        newValue = srcValue;
+      }
+      assignMergeValue(object, key, newValue);
+    }
+  });
+}
+
+module.exports = baseMerge;