eventually without customization never runs test method

[bddckr]

Using Kotest 5.8.1, the following test

class MyTestClass {
    @Test
    fun myTestMethod() = runTest {
        eventually {
            error("Whoops!")
        }
    }
}

(running in JUnit 4 - Android project)

immediately fails with

java.lang.AssertionError: Block failed after 0ms; attempted 0 time(s)

The test block is never run, and the output is really just the above, giving no further details about what went wrong.

---

I've dug into this and believe the issue is that the duration of the default EventuallyConfig is set to INFINITE:

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 118 in 4ad8070

var duration: Duration = Duration.INFINITE

which is then added to the start time:

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 208 in 4ad8070

val end = start + config.duration.inWholeMilliseconds

which results in an overflow, I believe. The result is that the check against the end time is immediately failing

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 245 in 4ad8070

fun hasAttemptsRemaining() = timeInMillis() < end && iterations < config.retries

---

While I initially wanted to raise this as a documentation issue only, I do wonder whether a duration of INFINITE should be handled specifically to mean "retry forever". Currently it basically results in "attempt not even once". To clarify: While the default value could simply be changed, I'm instead suggesting that EventuallyControl should be changed to allow retrying forever.

[mirageoasis]

I agree I think we have to change

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 245 in 4ad8070

fun hasAttemptsRemaining() = timeInMillis() < end && iterations < config.retries

or maybe

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 208 in 4ad8070

val end = start + config.duration.inWholeMilliseconds

can I write code this issue?

[Kantis]

@mirageoasis I think we could solve it by changing

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 208 in 4ad8070

val end = start + config.duration.inWholeMilliseconds

to

val end = maxOf(Long.MAX_VALUE, start + config.duration.inWholeMilliseconds) // prevent overflow

I think we could also reconsider using infinite duration for eventually as a default for 6.0

[mirageoasis]

@mirageoasis I think we could solve it by changing

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 208 in 4ad8070

val end = start + config.duration.inWholeMilliseconds

to

val end = maxOf(Long.MAX_VALUE, start + config.duration.inWholeMilliseconds) // prevent overflow

I think we could also reconsider using infinite duration for eventually as a default for 6.0

well that case only end up fixing end to Long.MAX_VALUE so I don't think it will be helpful

instead I suggest using code something like this

fun addSafely(a: Long, b: Long): Long {
    val sum = a + b
    if (a > 0 && b > 0 && sum < 0) {
        return Long.MAX_VALUE
    } else if (a < 0 && b < 0 && sum > 0) {
        return Long.MIN_VALUE
    } else {
        return sum
    }
}

kind of prototype code

[Kantis]

Will start ever be negative?

[mirageoasis]

Will start ever be negative?

if config.duration.inWholeMilliseconds value is 5

val end = maxOf(Long.MAX_VALUE, start + 5)

and end value will be Long.MAX_VALUE which I think will cause error

[mirageoasis]

Will start ever be negative?

instead I suggest other solution

kotest/kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/assertions/nondeterministic/eventually.kt

Line 245 in 4ad8070

fun hasAttemptsRemaining() = timeInMillis() < end && iterations < config.retries

instead fixing hasAttemptRemaing method

like if end value is already minus it makes while infinite loop

what about my idea?

[Kantis]

Feel free to publish a draft for further discussion :)