Using Jest in Watch Mode with test.todo to Test a Redux Reducer

Jest has a watch mode that can really speed up test development. It will automatically run your tests as you save your test files. And it has a built-in pattern option to allow you to only focus on tests for a particular file. This approach works well in combination with test.todo where you can stub out a number of tests and then code on them until they all pass.

Most of what is being done in these tests we've already seen before and it's important to note that I'm doing only the most basic of testing here. For each of these actions it wouldn't be uncommon in production to have 3-6 tests instead of just one.

It's important to note that it and test are aliases of one another so it.todo and test.todo both work seamlessly and are just a matter of preference. Usually when I'm doing unit testing I'll stick with describe and it, which commonly go together and I use test without describe when I'm testing react components with React Testing Library.