Function

Function instance

function/is

Confirms if given object is a native function

```javascript const isFunction = require("type/function/is");

isFunction(function () {}); // true isFunction(() => {}); // true isFunction(class {}); // true isFunction("foo"); // false ```

function/ensure

If given argument is a function object, it is returned back. Otherwise TypeError is thrown.

```javascript const ensureFunction = require("type/function/ensure");

const fn = function () {}; ensureFunction(fn); // fn ensureFunction(/foo/); // Thrown TypeError: /foo/ is not a function ```