kotlin-metadata class properties are always sorted alphabetically rather than in order of declaration

[dimsuz]

Having this class

data class Person(
  val firstName: String,
  val lastName: String,
  val age: String,
  val address: String,
  val phoneNumbers: List<String>,
  val friends: Map<String, String>
)

and calling

Person::class.toImmutableKmClass().properties.map { it.name }

produces:

[address, age, firstName, friends, lastName, phoneNumbers]

Is it possible to iterate them in order of declaration?
Not sure if this is a kotlin-metadata or kotlinpoet issue.

[ZacSweers]

I don't remember if we sort them (we do sort some things) or if this is how they come out of metadata. Agree they should use declaration order though, PR welcome if you want to fix!

[dimsuz]

Yes, I'll try to research this once I have some time (if no one will beat me to it).

[dimsuz]

I've researched this a bit and this appears to be the order in which kotlinx-metadata calls its visitors.

In kotlinx-metadata there's this call with propertyList argument. visitDeclarations then calls kotlinpoet's visitor with all these properties one by one. And first one is already address, i.e sorted alphabetically.

I wanted to find how exactly that propertyList property is created. It's a member of ProtoBuf.Class, but then I get lost in a huge JetBrains/kotlin repo and failed to find this class. I don't want to download and import all that repo rn.

Maybe there is a way to get a declaration order through other means and then do additional sorting on kotlinpoet's side? If anyone has a hint on how to do that, I might proceed, otherwise I think it should be reported to JetBrains. Youtrack I guess?

[ZacSweers]

Yeah youtrack is the best place to start and link it here

…

On Wed, Aug 12, 2020 at 4:11 PM dimsuz ***@***.***> wrote: I've researched this a bit and this appears to be the order in which kotlinx-metadata calls its visitors. In kotlinx-metadata there's [this call] with propertyList argument. visitDeclarations then calls kotlinpoet's visitor with all these properties. And first one is already address, i.e sorted alphabetically. I wanted to find how exactly that propertyList property is created. It's a member of ProtoBuf.Class, but then I get lost in a huge JetBrains/kotlin repo and failed to find this class. I don't want to download and import all that repo rn. Maybe there is a way to get a declaration order through other means and then do additional sorting on kotlinpoet's side? If anyone has a hint on how to do that, I might proceed, otherwise I think it should be reported to JetBrains. Youtrack I guess? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#965 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKMJPTSMTJPHUM7S6AZSPTSALZN7ANCNFSM4P3WMJZA> .

[dimsuz]

Reported to youtrack: https://youtrack.jetbrains.com/issue/KT-41042

[ZacSweers]

One thing we could look into in the mean time is trying to interpret the ordering from the reflection/elements source. Moshi would definitely want this. @swankjesse @Egorand what do you think?

[dimsuz]

I have just done that in my library. In my case that's an annotation processor, so I've used TypeElement.enclosedElements to read the field order and then sort kotlinpoet's property specs according to that.

[ZacSweers]

Want to send a PR? I think we need to factor method order too and give priority in order of constructor parameters, public setters, public getters, and finally public fields. I don’t think there’s a case where there would be private anything that we’d use.

…

On Sat, Aug 15, 2020 at 6:27 PM dimsuz ***@***.***> wrote: I have just done that in my library. In my case that's an annotation processor, so I've used TypeElement.enclosedElements to read the field order and then sort kotlinpoet's property specs according to that. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#965 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKMJPVEJ3DMYRD345TBBDLSA4DTZANCNFSM4P3WMJZA> .

[Egorand]

Makes sense to me, a PR would be great!

[dimsuz]

I will try to come up with a PR, but not sure how fast I will able to do this. If anyone would like to work on this too, please do it.

[ZacSweers]

Just to share from the above youtrack link - this is an issue in metadata itself. kotlinx-serialization wants this ordering support though too, so optimistic something will come down the pipeline