Recursive avro schema type in schema registry - avro

Question

I want to create an Avro schema for schema registry for the following Typescript code:
export type Value = {
[key: string]:
| Value
| Value[]
| string
| number;
};
It's a recursive map type. I know it is possible to create a recursive record like below, but it's a different use case.
export type Node = {
value: number;
leafs: Node[];
}
I tried different approaches, including named types and schema references, but all resulted in validation errors when publishing a schema.
A simplified schema (excluding the recursive array) that is desired but invalid looks like this:
{
"type": "record",
"name": "Value",
"namespace": "com.namespace",
"fields": [
{ "name": "itemValues", "type": { "type": "map", "values": ["string", "int", "itemValues"] } }
]
}
Most of variations of this schema result in an error: org.apache.avro.SchemaParseException: Undefined name: "itemValues"
I could not find examples of similar scenarios and wondered if it's even possible to create one like this? The limitation for that would most likely be the lack of named union and map types in Avro.
Update
An example JSON that I want to achieve:
{
"itemValues": {
"validA": "sth",
"validB": [],
"validC": 8,
"recursiveProperty": {
"anyMap": { "sth": "else" }
}
}
}

Answer 1

The problem with your schema is that your values list is ["string", "int", "itemValues"], but the parser is complaining because you have told it there should be some type itemValues and you haven't defined one. The only type you have defined is Value.
Here's the fixed schema (including adding the array of Value as one of the potential types:
{
"type": "record",
"name": "Value",
"namespace": "com.namespace",
"fields": [
{ "name": "itemValues", "type": { "type": "map", "values": ["string", "int", "Value", {"type": "array", "items": "Value"}] } }
]
}