Json Schema - Marking unique array from set

tapir
1

Hello all,

I’m working on moving json schema generation from GitHub - andyglow/scala-jsonschema: Scala JSON Schema to Tapir Json Schema generation.

Among some differences, I found one useful that could be added to Tapir Schema.
scala-jsonschema describes Set[_] with “uniqueItems”:

"SetWithEnums": {
    "default": [],
    "items": {
        "$ref": "#/definitions/MyEnum"
    },
    "type": "array",
    "uniqueItems": true
}

Tapir Json Schema is not adding “uniqueItems”

"SetWithEnums" : {
    "type" : "array",
    "items" : {
        "$ref" : "#/$defs/MyEnum"
    }
}

Maybe this would be useful to add “uniqueItems” to Tapir Json Schema generation?

2

True, we could probably do this via an attribute on the schema (and supporting this attribute appropriately in the interpreter). Can you create an issue to add that?

3

Thank you!
I created [FEATURE] Json Schema - Include uniqueItems when array is created from Set · Issue #3441 · softwaremill/tapir · GitHub

Also I have one more questions about other difference:
Is there a way to configure Tapir Schema generation to mark arrays as “required”?

I want to explicitly say that I will always return "myCollection": [],.

In scala-jsonschema not setting default value for collection will end up with having it in schema required list:

case class Test(myCollection: Seq[String])

Then schema includes:

"required": [
  "myCollection"
]

Adding default will remove that from required.
I’m not saying that this way of configuration is great in scala-jsonschema (I would say it’s rather surprising). But it’s possible.

Is there any way to add arrays as “required” in Tapir generated schema?

4

Yes, that issue was raised before, but there’s no simple solution (due to schema derivation being context-free). See: `asIterable` always creates optional properties · Issue #993 · softwaremill/tapir · GitHub - there are some work-arounds.