Hi guys, just general knowledge question about test case. How may test should case will be used in t...

# getting-started

[KotlinLeaner]

Hi guys, just general knowledge question about test case. How may test should case will be used in this piece of code

internal fun checkRange(valueOne: Int, valueTwo: Int): Boolean {
    val rangeInValueOne = 0..10
    val rangeInValueTwo = 20..30
    return (valueOne in rangeInValueOne && valueTwo in rangeInValueTwo)
}

?

[KotlinLeaner]

I think 4 will be good?

[KotlinLeaner]

If we go truth table

rangeInValueOne = true
rangeInValueTwo = true

rangeInValueOne = false
rangeInValueTwo = false

rangeInValueOne = false
rangeInValueTwo = true

rangeInValueOne = true
rangeInValueTwo = false

Is I am right?

[Jacob]

Some would say that every range check could have 4 tests.:
At the lower bound and IN.
At the Lower bound but Out,
At the higher bound and IN.
At the higher bound but Out,

[Jacob]

Some might argue in the opposite direction, If you tested (true, false) and (false, true) do you really need to test (false, false)? There's no one right answer

[Jacob]

a false false test only proves that the code didn't do a xor. xors don't just happen by accident

[Jacob]

In terms of coverage, it's not covering a new branch since the code short circuits on the first false

[KotlinLeaner]

So what is the right way to do test. I am just want feedback for you guys.

[KotlinLeaner]

What do you suggest to test in this function?

[Jacob]

(0, 20) -> true
(10, 30) -> true
(-1, 20) -> false
(11, 20) -> false
(0, 19) -> false
(0, 31) -> false