If you’ve been following this blog for some time, you know I develop software mostly using test-driven development AKA TDD. But while this mostly means unit tests, it shouldn’t be limited to only unit tests. At one of my current clients, we use AWS Lambda functions written in TypeScript. These are (usually) relatively small blocks of code that can be invoked by a HTTP call. The function has a very limited scope of what it can be used for, i.e.