mjackson/expect — pull request #1 by raydog (2014-11-15 09:23:51+00:00)
Title: Added existence checks and made assertions chainable

This pull request adds two new checks: `toExist` and `toNotExist`, which checks for truthy and falsy values respectively.

It also makes the API chainable. In most circumstances, this won't matter, but you can use it to remove a lot of repetition for certain tests. For example:

```javascript
expect([1, 2, "foo", 3])
.toExist()
.toBeAn(Array)
.toInclude("foo")
.toExclude("bar");
```