Mypy is a type checker for Python that allows you to introduce static type checking into your projects.
Introducing optional static typing into Python has a large number of benefits that grow in importance when project size and complexity increases. Python is an extremely dynamic language that allows you to be very flexible with the types that are passed around. With this flexibility comes the possibility to introduce a number of type related bugs. Introducing tooling that will allow you to check how the types of variables flow through your program allows you to detect many subtle bugs before you even run your code.
Last night Robbie Clarken presented a great talk about Mocking and how it fits in with testing in general. There were a few questions he had over email about how mypy could be used in addition to Mocking to get better coverage of issues with parameters in function calls being tested. Seeing as this is helping him with a real process we agreed that there's value in blogging this so a wider audience can get exposure to these techniques.Published on July 20th, 2018 by Janis Lesinskis.