We've covered a lot here! You learned how to write unit tests in Solidity and JavaScript. Specifically, you learned how to test for modifiers, public functions, state modifications, and events! Remember, testing is a vital part of any software development—not just smart contract development. Just as with any software, writing unit tests is absolutely crucial to ensuring that your application works well in production and makes users happy.
See you in Chapter 7, Truffle Gotchas and Best Practices, where we learn about best practices and gotchas in Truffle!