Mutating the subject
Often times we want to check a specific aspect of a value but when doing the processing manually we will loose the nice error descriptions given by ass expressions.
ass integrates LoDash to provide a powerful data manipulation mechanism with a known interface.
Hint
When the subject is mutated it stays that way for the rest of the expression.
If you have other needs check out the .and combinator.
ass(data).size.eq(10) // a collection with a size of 10
ass(data).pluck('name').has('Juan') // contains a person named Juan!
While the expression resolves the subject value under test may mutate but
we can always get back the original by calling .value, if we're actually
interested in the mutated one we can access it with .result().
var data = 'abcdef';
ass(data).size.value === 'abcdef';
ass(data).size.result() === 6;