i was thinking why tests are defined in classes instead of j

Question

i was thinking why tests are defined in classes instead of just in top level and i guess the main reason is discovery but why are they classes and not objects

Javier · Answer

object works

sam · Answer

Yeah objects should work

christophsturm · Answer

cool I never tried it because the examples all use classes aren t objects more natural if they are just used for discovery

sam · Answer

Yep

sam · Answer

You can t reuse vals in objects tho

sam · Answer

Like the framework can t instantiate new instances

christophsturm · Answer

```object IsolationTest FunSpec isolationMode = IsolationMode InstancePerTest context ctx val uuid = UUID randomUUID toString test 1 println uuid$uuid test 2 println uuid$uuid ``` I created a new project with just this test and neither the gradle plugin nor the idea plugin finds it if i change it to class it works

christophsturm · Answer

also i was thinking about InstancePerTest vs single instance the class instance does not really matter to me because the variables are defined in the body of the context method and i think most people don t declare their dependencies on the class

sam · Answer

I put all my vals in the instance but that could be me being odd

christophsturm · Answer

btw how does that work i have no idea how this can be implemented how does it run test 2 in a fresh created context

sam · Answer

With classes it can make a new instance

christophsturm · Answer

my kotest classes don t even have a body because I use funspec and everything is in the constructor

sam · Answer

Same thing Everything in the class is created fresh with a new instance

christophsturm · Answer

hmm but the uuid field is a local variable in the context method

sam · Answer

For local variables it s no different to invoking a method twice

christophsturm · Answer

ok and in the second invocation of context it skips the first test

sam · Answer

Yes

christophsturm · Answer

so it runs the context method twice and each time it runs only one test

sam · Answer

Yep

sam · Answer

It skips any nested contexts or tests as required

christophsturm · Answer

now that i understand it its really simple i guess in never thought it through and i also think that no other test framework does it like that

christophsturm · Answer

or maybe scalatest surely not rspec

sam · Answer

Once I wrote it it ended up being surprisingly straightforward

sam · Answer

It s also why fixtures aren t really needed Just use vals

christophsturm · Answer

yeah

sam · Answer

I could introduce fixtures too though if people just prefer the syntax

sam · Answer

In 4 4 there will also be parallelism at the test level default to off

christophsturm · Answer

i was wondering if a syntax without classes is possible just a context call at the file level but probably no easy way to discover the tests then

christophsturm · Answer

maybe i could help out with the paralellism Is there some work done already

sam · Answer

The problem isn t discovering top level tests because they get compiled as statics in classes anyway

sam · Answer

The problem is in the syntax I m not sure it ends up looking any nicer

sam · Answer

Kotlin supports top level classes objects functions and vals

sam · Answer

So you can t just write `test foo `

sam · Answer

because that s a function call not a function declaration

sam · Answer

you could do `val mytest = test foo ` though but then you need to name the val and the test

sam · Answer

I guess we could introduce something like this `val mytest = test `

sam · Answer

which is similar to the factory builders we currently have which are ```val factory = funSpec test here ```

sam · Answer

The downside being you have the junit style problem of having to put your test name into a variable so it ends up looking like `val myTestWithLongNameTestingThings = ` or you have to back tick the names

christophsturm · Answer

hmm you could just put the test method calls into a main method slightly smiling face

sam · Answer

yeah you could but then `fun main ` isn t much time saving over `class Foo FunSpec `

sam · Answer

I wonder if kts kotlin scripts could work

christophsturm · Answer

classes just somehow feel wrong maybe thats just a relict of junit type thinking in the end we just need some group of method calls that can be discovered like a kts script for example

christophsturm · Answer

btw do you have an idea why my test object from above is not found by the kotest runner

sam · Answer

I agree Classes don t get you anything I mean even moving from function declarations to function invocations is a mind shift for testing

sam · Answer

So many tools like gradle assume that all tests are method defined in a class

sam · Answer

Maybe objects aren t working properly I thought they were supported and there s no reason they can t be We don t have any tests for it though Tht could be considered a bug and should be easily fixable for 4 3 2

christophsturm · Answer

ok I ll file a ticket

sam · Answer

thanks

sam · Answer

Kotlin script

sam · Answer

That s really nice

christophsturm · Answer

one reason why I m thinking of this is for faster startup when i put this into my kotest config i see that it takes 2 to 3 seconds until my tests start running ``` override fun beforeAll val uptime = ManagementFactory getRuntimeMXBean uptime println beforeAll started after $uptime ```

sam · Answer

It could be the scanning phase

sam · Answer

If you enable KOTEST DEBUG=true

sam · Answer

you should see info

sam · Answer

You would need to set that as an env var and make sure its exported to the forked process

christophsturm · Answer

``` gt Task kotest OpenJDK 64 Bit Server VM warning Option AllowRedefinitionToAddDeleteMethods was deprecated in version 13 0 and will likely be removed in a future release Starting test discovery scan Test discovery completed in 1135ms After filters there are 13 spec classes After discovery extensions there are 13 spec classes Discovery is returning 13 specs ~~~ Kotest Configuration ~~~ gt Parallelization factor 12 gt Default test timeout 600000ms gt Default test order Sequential gt Default isolation mode InstancePerTest gt Global soft assertations False gt Write spec failure file False gt Fail on ignored tests False gt Spec execution order SpecExecutionOrder gt Extensions io kotest engine extensions SystemPropertyTagExtension io kotest core extensions RuntimeTagExtension io kotest engine extensions RuntimeTagExpressionExtension io kotest engine extensions SpecifiedTagsTagExtension gt Listeners class io kotest engine config LoadConfigFromClasspathKt$toDetectedConfig$beforeAfterAllListener$1 gt gt Kotest Mama always said testing was like a box of chocolates You don t know which ones are gonna fail Test plan has 13 specs invokeBeforeProject beforeAll startet after 2525```

christophsturm · Answer

so test discovery is 1 1s and total time to beforeAll is 2 5s

sam · Answer

which version of kotest

christophsturm · Answer

thats total jvm uptime

christophsturm · Answer

4 3 1

sam · Answer

to be fair it might be taking 1 second to load the jvm

sam · Answer

then 1 second to find the specs

christophsturm · Answer

test discovery could output the uptime too then its easier to see

sam · Answer

agreed

sam · Answer

start time and end time

christophsturm · Answer

can i just use kotest from a composite build and run it via the gradle kotest plugin

christophsturm · Answer

then i can try with kotest master

sam · Answer

I m not sure what you mean

christophsturm · Answer

use kotest in my project via a composite gradle build

sam · Answer

I don t know what you mean by a composite build By the way using a kts file with this syntax the tests are output to a class per test So it would be possible to find the tests easily using the regular discovery mechanism

sam · Answer

The vals for configuration are placed into another class though so that might require some trickery Or different syntax

christophsturm · Answer

composite build = `includeBuild kotest ` in settings gradle kts

sam · Answer

I didn t know that existed

christophsturm · Answer

thats super useful to try local changes

christophsturm · Answer

sam · Answer

Yes it looks super useful Gonna read about that

sam · Answer

The gradle plugin only requires you to have ```io kotest engine launcher MainKt``` and ```io kotest engine reporter TaycanConsoleReporter``` on your classpath and then the usual kotest stuff like framework So it should work