Mocha‑Lazy‑BDD is a plugin that extends Mocha’s BDD interface with RSpec‑style `lazy` and `subject` macros, letting developers define memoized values (`let`) and a default subject directly on the test context. It’s aimed at JavaScript developers (ES5+), especially those using Mocha with Chai, who want a more concise, RSpec‑like way to write setup code in their unit tests. Installation is as simple as adding the module and loading it with `mocha -u mocha-lazy-bdd` (or via Bower for browsers).