I'm using Kotest's data class matchers to compare two data classes that each contain a field with an...

# kotest

[Sebastian Schuberth]

I'm using Kotest's data class matchers to compare two data classes that each contain a field with an instance of a sealed class. While the sealed class instances are different, their data is the same. This makes the test fail. Is this expected? I would have assumed sealed class properties should be compared by their values, just like nested data classes.

[sam]

Only fields are used. Are you sure they're exactly the same ?

[Sebastian Schuberth]

I'm seeing this as part of Kotest's data class diff output:

[Sebastian Schuberth]

referenceCategory=OTHER, referenceType=org.ossreviewtoolkit.utils.spdx.model.SpdxExternalReference$Type$Other@aa32f88, referenceLocator=acmecorp/acmenator/4.1.3-alpha), 
referenceCategory=OTHER, referenceType=org.ossreviewtoolkit.utils.spdx.model.SpdxExternalReference$Type$Other@67eaebca, referenceLocator=acmecorp/acmenator/4.1.3-alpha),

[Sebastian Schuberth]

where "Other" is a sealed class

[Sebastian Schuberth]

and these seem to be compared by instance, not by fields...

[Sebastian Schuberth]

I'm comparing this data class: https://github.com/oss-review-toolkit/ort/blob/master/utils/spdx/src/main/kotlin/model/SpdxExternalReference.kt

[Emil Kantis]

Looks like it's just a sealed class? For data classes there's auto generated equals method, but that's not the case for arbitrary sealed classes

[Sebastian Schuberth]

Right, which is why I was assuming Kotest would compare the properties of a sealed class manually...

[Emil Kantis]

Why not mark Other as a data class if you need auto-generated equals by properties? it doesn’t feel like it would sense to automatically compare any sealed class within the same hierarchy using properties by default

[Sebastian Schuberth]

What do you mean by "mark"? Just "declare"? Well, of course there's a reason why Other is a sealed class... we need some sort of enum there. And we usually do not need property-equality for this class, other than the Kotest use-case. That said, should it work if I override equals / hashcode for the sealed class?

[Emil Kantis]

Sealed and data are not mutually exclusive. sealed data class could be used. Anyway, I think adding equals / hash code should also do the trick

[Sebastian Schuberth]

Oh, I need to check sealed data class then, thanks!

[Sebastian Schuberth]

:-(

[Sebastian Schuberth]

Ah, sorry, you probably mean the nested class to be a data class!