A Beginner's Guide to Test Driven Development With Symfony and Codeception - Part 2

In this tutorial, we'll continue our journey into Test-Driven Development (TDD) by building out the functionality for transferring funds between users in an API application built using Symfony. We'll write tests first and then implement the necessary code to make those tests pass. Along the way, we'll learn about some new concepts such as: - Customizing Codeception assertions - Writing custom helpers in Codeception - Using Doctrine Repositories for data access - Implementing a custom user authenticator with Symfony Security - Refactoring code to remove duplication and improve readability - Ensuring that our application is secure by preventing negative transfer amounts, invalid parameters, insufficient funds, and transfers to non-existent users. ```