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Hey there, I've created some extension functions t...
# kotest-contributors
a
Hey there, I've created some extension functions to make testing time a little easier, using kotest Essentially, it enables the following:
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// BACKWARD time - defaults to 'ZonedDateTime.now()'
createdAt shouldBeWithinLast Duration.ofSeconds(1)

// FORWARD time - defaults to 'ZonedDateTime.now()'
deletedAt shouldBeWithinNext Duration.ofHour(1)


// BACKWARD time - setting custom 'base' time
val yesterdayAtNoon = ZonedDateTime.now()
        .minusDays(1)
        .with(LocalTime.of(12, 0)   
updatedAt shouldBeWithin Duration.ofDay(1) from yesterdayAtNoon

// FORWARD time - setting custom 'base' time
val tomorrowAtNoon = ZonedDateTime.now()
        .plusDays(1)
        .with(LocalTime.of(12, 0)   
updatedAt shouldBeWithin Duration.ofDay(1) to tomorrowAtNoon
What do you folks think? I'm happy to open a PR to bring it in. Not quite sure which package it should go in though
Also includes some internal util functions to make the output simpler to read:
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Expected time (2024-09-15T18:53:03.060038Z) to be within 1 milliseconds to now, but the difference was 167 milliseconds
e
Iirc we already have the equivalent of those 🤔
a
oh.. really? I couldn't find it when I was searching around 😂
I needed it to test some specific integration code where I don't know some values when invoking an API I would have used it if I had known it existed
e
Image from iOS.jpg
a
Could you link sorry? I don't see it on https://kotest.io/docs/
e
Kinda similar at least 🙂
a
Ah.. yeah found it now
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createdAt plusOrMinus 10.days
I guess I didn't notice the 
plusOrMinus
because I was expecting 
should
as a prefix
The only difference is that 
plusOrMinus
doesn't allow you to specify another base time to compare against But that might not be super useful I guess
ohh.. I see now It's a chain actually
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createdAt shouldBe now plusOrMinus 1.seconds
Where now = 
ZonedDateTime.now()
I didn't understand that. And was confused why it was always passing
e
Yeah 👍
a
I guess it's tricky to make that a compilation error, as
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createdAt plusOrMinus 1.seconds
is syntactically correct Perhaps it's just that I'm new to Kotlin 😄 (as you can maybe tell from my old Java usage of 
Duration.ofSeconds
)
e
👀 1
a
Would you be happy to accept a contribution that added a default for 
now
as a helper? A lot of my comparisons are against 
now
so repeating
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createdAt shouldBe now plusOrMinus 1.seconds
Vs something like
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createdAt shouldBe nowPlusOrMinus 1.seconds
(Happy to take suggestions on naming!)
e
If it’s a general pattern, sure. Can you find more usages of 
now plusOrMinus
with a GitHub search for instance?
a
hmm Sadly not much (all our usage is in private repos for my company) I see this, which is maybe like it? There is this one which is almost exactly like my usage But other than that, my query isn't turning up much 😓
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"shouldBe" "now" " plusOrMinus" language:Kotlin
I'm happy to just keep it as an internal (to our codebase) extension function if you'd prefer
Using
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infix fun ZonedDateTime.nowPlusOrMinus(duration: Duration): ZonedDateTimeToleranceMatcher =
    this shouldBe ZonedDateTime.now(this.zone) plusOrMinus(duration)
in our code now 👍
e
I’ll do a search across my client’s private repos as well..
🙌 1
a
@Emil Kantis sorry for following up, but just want to make sure I'm doing this correctly
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createdAt shouldBe now plusOrMinus 1.seconds
Am I using this wrong?
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io.kotest.assertions.AssertionFailedError: expected:<2024-09-15T19:58:14.160949Z> but was:<2024-09-15T19:58:13.974671Z>
By my maths, they're ~ 0.1 second from each other?
e
Hmm, wonder if it’s getting silently “discarded” due to functions being applied left to right..
Add parens around now plusorminus 1..
⚙️ 1
a
Yeap, that worked
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createdAt shouldBe (now plusOrMinus 1.seconds)
e
What’s the signature of plusOrMinus? Feels odd that it can be applied to the result of shouldBe.. but I guess shouldBe returns the left-hand operand which is also compatible..
a
That's just the default kotest - not anything I've modified so
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infix fun ZonedDateTime.plusOrMinus(tolerance: Duration): ZonedDateTimeToleranceMatcher =
   ZonedDateTimeToleranceMatcher(this, tolerance)
e
We should probably add JSR305 
@CheckReturnValue
on plusOrMinus to avoid that.. since it only works with JVM types, it should be fine to use the JVM-only annotation
💯 1
👌 1
a
hmm. I added that as a quick temporary function, but it still failed
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@CheckReturnValue
infix fun ZonedDateTime.plusOrMinus(tolerance: Duration): ZonedDateTimeToleranceMatcher =
   ZonedDateTimeToleranceMatcher(this, tolerance)
Am I just using the function incorrectly?
hmm. I think I know the issue I will try making a small test case in my kotest fork and see if I can replicate there
a
We should describe this parenthesis thing in the docs
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