Use Assert package in the test files

[rexposadas]

Rationale

I suggest using the assert package in the tests. See: https://github.com/stretchr/testify

It'll make the code cleaner. For example in api_test.go we have:

	if err == nil {
		t.Fatal("ListEngines did not fail")
	}
```	

That can be changed to: 

```go	
assert.NoErrorf(t, err, "ListEngines did not fail")

Implementation

I've implemented this feature for production level code and it makes the test code look a lot cleaner.

If you agree with the suggestion, I am willing to make the PR for it.

[sashabaranov]

@rexposadas Thank you for the suggestion! Our library aims to have no dependencies for as long as possible. While the testify library has some helpful features, they are not enough to make it a dependency. Having said that — we can add the single-line error checking in tests to the library. Your contribution would be greatly appreciated, along with any code coverage improvements 🙌🏻

[rexposadas]

I see. No problem.

we can add the single-line error checking in tests to the library

Which library are you referring to? Would it be this one? https://github.com/sashabaranov/go-fastapi

[sashabaranov]

@rexposadas I mean to this library, just as a function e.g.

func checkNoError(t *testing.T, err error, message string) {
	if err != nil {
		t.Errorf(message)
	}
}

[rexposadas]

@sashabaranov But, to keep the code consistent would mean making other functions such as:

checkHasError (..), checkErrorIs(..)

You're OK with that?

[sashabaranov]

@rexposadas sounds good! It might also make sense to put those into internal/test package, but I trust your judgment here.

[rexposadas]

Great. I'll work on the PR.

[rexposadas]

PR for this has been merged.