test: Make sure to verify the extra credit button behavior

[Snaptags]

It might be nice to verify the button actually increases the existing value. If you start to implement the extra credit requirements you might accidentally set the count to "step". Then the test would still be green, it only fails when you try to click the button again…

[kentcdodds]

@Snaptags, could you update your branch to the latest? This test changed quite a bit. Also, I'm not sure what these changes do to help. Could you elaborate?

[Snaptags]

Sorry, did not upgrade my fork first 😞

The test gives a deceptive feeling of safety when starting the extra credit 1 exercise: If you just apply the changes suggested by the instructions, the test immediately is green again. Because, accidentally, replacing the state by the step (1 in this case) is a valid result.

const [count, changeCount] = React.useReducer(countReducer, initialCount)
const increment = () => changeCount(step)

But people have to change the reducer implementation, too. By clicking the increase button twice the test makes sure that you don't mess up the reducer while refactoring. And to make sure you actually can increase the counter more than once.

[kentcdodds]

That makes total sense. Thank you!

[kentcdodds]

@all-contributors please add @Snaptags for tests

[allcontributors]

@kentcdodds

I've put up a pull request to add @Snaptags! 🎉