SQL DDL code generation error - empty JSON property

[shoffmeister]

Given a specific (valid, albeit odd) JSON schema, kwack will generate invalid SQL, which will then lead to

java.lang.RuntimeException: Could not execute DDL: CREATE TABLE IF NOT EXISTS "my-topic" (rowkey VARCHAR NULL, "extensions" STRUCT() NOT NULL, rowinfo rowinfo)

Caused by: java.sql.SQLException: Parser Error: syntax error at or near ")"

In the SQL note the STRUCT() - this is triggered by an object without any properties.

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "extensions": {
      "$ref": "#/components/PersonSyncEventExtensions"
    }
  },
  "components": {
    "PersonSyncEventExtensions": {
      "type": "object"
    }
  }
}

[shoffmeister]

That oddity is derived from a real-life, complex JSON schema (1500 lines of JSON) - so definitely a corner case, but also observed in the wild.