Mastering React Test-Driven Development

Not testing at all

There is a belief that TDD doesn't apply to some scenarios in which it clearly does – for example, if your code is 'throwaway' (whatever that means), or if it's presumed to never need modification once it's deployed. Believing this, is almost ensuring the opposite to be true. Code, particularly code without tests, has a habit of living on beyond its intended lifespan.

In addition to reducing the fear of changing code, tests also reduce the fear of removing code. Without tests, you'll read some code and think "maybe something uses this code for some purpose I don't quite remember...". With tests in place, this won't be a concern. You'll read the test, see that the test no longer applies due to a changed requirement, and ...