Having to specify a default empty constructor in version 2.18

[imfrostii8]

I want to start by saying this is most likely lack of understanding on my side.

In version 2.17 I was able to do map json to an object like this even if the List was actually empty.

data class SomeObject(
    val data : List<AnotherObject>
)

When I upgraded to version 2.18 I noticed that I have to initialise the list as an empty list to prevent some errors when the json comes empty.
I searched the release notes and couldn't find anything, likely because half of it I don't get it. The question is: is this the proper way to handle this cases now or should I be doing something differently ?

data class SomeObject(
    val data : List<AnotherObject> = emptyList()
)

[pjfanning]

Could you try jackson-databind 2.18.2-SNAPSHOT? See FasterXML/jackson-databind#4777 (comment) -- seems possibly similar.

[JooHyukKim]

+1 on what @pjfanning suggested.
Also the input JSON or (even better) mapper configuration too! just in case :))

[imfrostii8]

Yes that works, thanks for pointing me in the right direction

[cowtowncoder]

Also: instead of saying "upgrade to 2.18" could you include full version (2.18.0 or 2.18.1) just to make sure it's clear exact version you used. Based on discussion I assume 2.18.1 did not yet fix the issue, but 2.18.2 will (if 2.18.2-SNAPSHOT) works.

[imfrostii8]

OK, after some further investigation on my side I can say that I was running jackson-module-kotlin:2.17.2 and jackson-databind:2.17.2. After updating jackson-module-kotlin to 2.18.1 I had to initialise the object like above, if I match jackson-databind to 2.18.1 there's no need to initialise it.
So if running both in 2.18.1 it works as it was working before. A lot of confusion on my side

[cowtowncoder]

Ok it is tricky; thank you fo confirming @imfrostii8. I will close the discussion then.