Bump to v3.0.0.

object/invert.js

@@ -0,0 +1,62 @@
+import isIterateeCall from '../internal/isIterateeCall';
+import keys from './keys';
+
+/** Used for native method references. */
+var objectProto = Object.prototype;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
+/**
+ * Creates an object composed of the inverted keys and values of `object`.
+ * If `object` contains duplicate values, subsequent values overwrite property
+ * assignments of previous values unless `multiValue` is `true`.
+ *
+ * @static
+ * @memberOf _
+ * @category Object
+ * @param {Object} object The object to invert.
+ * @param {boolean} [multiValue] Allow multiple values per key.
+ * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
+ * @returns {Object} Returns the new inverted object.
+ * @example
+ *
+ * _.invert({ 'first': 'fred', 'second': 'barney' });
+ * // => { 'fred': 'first', 'barney': 'second' }
+ *
+ * // without `multiValue`
+ * _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' });
+ * // => { 'fred': 'third', 'barney': 'second' }
+ *
+ * // with `multiValue`
+ * _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' }, true);
+ * // => { 'fred': ['first', 'third'], 'barney': ['second'] }
+ */
+function invert(object, multiValue, guard) {
+  if (guard && isIterateeCall(object, multiValue, guard)) {
+    multiValue = null;
+  }
+  var index = -1,
+      props = keys(object),
+      length = props.length,
+      result = {};
+
+  while (++index < length) {
+    var key = props[index],
+        value = object[key];
+
+    if (multiValue) {
+      if (hasOwnProperty.call(result, value)) {
+        result[value].push(key);
+      } else {
+        result[value] = [key];
+      }
+    }
+    else {
+      result[value] = key;
+    }
+  }
+  return result;
+}
+
+export default invert;