Left Pad

Problem

You know what, left pad is javascript package and referenced by React: Github link

One day his author unpublished it, then a lot of javascript projects in the world broken.

You can see from github it's only 11 lines.

You job is to implement the left pad function. If you do not know what left pad does, see examples below and guess.

Example

leftpad('foo', 5) >> '  foo';

leftpad('foobar', 6) >> 'foobar';

leftpad('1', 2, '0') >> '01';