fix(challenge): remove type coercion check for true and false return

[lasjorg]

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This PR removes the type coercion from the test and adds strict checking for false/true return values.

The current test will coerce an undefined return value from the function, making both "false" tests pass right out of the gate. I don't think this is a good starting point. All tests should fail by default and not give the user the wrong impression that their function is passing some of the tests even if they are not returning anything. Returning truthy/falsy values (other then true/false) should not make any test pass/fail.

[lasjorg]

I guess maybe I should have used the Chai methods (isTrue/isFalse). Is it preferred to use chai methods when possible?

There doesn't seem to be any mention of it in the style guide. If it is preferred maybe we should add that to the Writing tests part of the style guide?

[ojeytonwilliams]

LGTM 👍

[ojeytonwilliams]

@lasjorg regarding Chai, I think it's always used. The assert object is just Chai's assert, rather than Node's.

A PR fixing the docs would be great if you have the time. Let me know, either way.

[lasjorg]

@ojeytonwilliams I just meant if Chai has an assert method, like isTrue, deepEqual, etc. if its usage should be encouraged over making your own test expressions. And If so, if this should be mentioned in the Writing tests part of the style guide.

For it to have any meaningful effect I guess it would need to be, at least loosely, enforced as part of the code review process as well. I'm just thinking if enforcing/encouraging it might potentially help make tests a bit cleaner.

Not sure if I should make an issue and ask for feedback on this?

[ojeytonwilliams]

Oh, I see what you're saying. I don't think we want to be too dogmatic, but encouraging their use can't hurt.

That said, making an issue's a reasonable idea, just for visibility. So, please go ahead.

[moT01]

LGTM @lasjorg 🎉 Thanks for contributing 🎉