--- /dev/null
+var assignValue = require('./_assignValue'),
+ baseToPath = require('./_baseToPath'),
+ isIndex = require('./_isIndex'),
+ isKey = require('./_isKey'),
+ isObject = require('./isObject');
+
+/**
+ * The base implementation of `_.set`.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @param {Array|string} path The path of the property to set.
+ * @param {*} value The value to set.
+ * @param {Function} [customizer] The function to customize path creation.
+ * @returns {Object} Returns `object`.
+ */
+function baseSet(object, path, value, customizer) {
+ path = isKey(path, object) ? [path + ''] : baseToPath(path);
+
+ var index = -1,
+ length = path.length,
+ lastIndex = length - 1,
+ nested = object;
+
+ while (nested != null && ++index < length) {
+ var key = path[index];
+ if (isObject(nested)) {
+ var newValue = value;
+ if (index != lastIndex) {
+ var objValue = nested[key];
+ newValue = customizer ? customizer(objValue, key, nested) : undefined;
+ if (newValue === undefined) {
+ newValue = objValue == null ? (isIndex(path[index + 1]) ? [] : {}) : objValue;
+ }
+ }
+ assignValue(nested, key, newValue);
+ }
+ nested = nested[key];
+ }
+ return object;
+}
+
+module.exports = baseSet;