The test runner in the hapi ecosystem is called lab. If you're not familiar with test runners, they are a Command-line Interface (CLI) tool for running your testing suite. It is inspired by a similar test tool called mocha, and in fact, initially began as a fork of the mocha codebase. But as hapi's needs diverged from the original focus of mocha, lab was born.
code is the assertion library commonly used in the hapi ecosystem. An assertion library forms the part of a test that performs the actual checks to judge whether a test case has passed or not, for example, checking if the value of a variable is true after an action has been taken.
Let's look at our first test script, then we can take a deeper look at lab and code, how they function under the hood, and some differences they have with other commonly-used libraries such as mocha and chai.