Check out a free preview of the full Unit Testing JavaScript (with CoffeeScript) course:
The "Video 3: Captors" Lesson is part of the full, Unit Testing JavaScript (with CoffeeScript) course featured in this preview video. Here's what you'd learn in this lesson:
A captor will save an argument value passed to a function and allow it to be recalled later. Dave and Justin walk through the code for creating a captor and verifying a test is passing once the production code is written.