Updated longestItem + tests

snippets/longestItem.md

@@ -1,11 +1,13 @@
 ### longestItem
 
 Takes any number of iterable objects or objects with a `length` property and returns the longest one.
+If multiple objects have the same length, the first one will be returned.
+Returns `undefined` if no arguments are provided.
 
-Use `Array.reduce()` to collect the longest element.  Returns [] for empty array.
+Use `Array.reduce()`, comparing the `length` of objects to find the longest one.  
 
 ```js
-const longestItem = (...vals) => [...vals].reduce((a, x) => (a.length > x.length ? a : x), []);
+const longestItem = (val, ...vals) => [val, ...vals].reduce((a, x) => x.length > a.length ? x : a);
 ```
 
 ```js