[AVRO-3979] Python SchemaCompatibility doesn't set location properly for type mismatch with writer unions

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.12.0, 1.11.3, 1.11.4
• Component/s: python
• Release Note: Python: Fixes schema incompatibility location for a type mismatch with a writer union schema.

Language

Python

• Assignee: Unassigned
• Reporter: Chanzo Bryan
• Created: 23/Apr/24 05:20
• Updated: 23/Apr/24 05:21

Description

When a reader schema has a type mismatch with a writer schema where the writer schema type is a union, the location information for the schema compatibility is lost in Python. This was fixed in Java as a part of AVRO-3612.

Given a reader record schema with int field a:

{
  "type": "record",
  "name": "Record1",
  "fields": [
    {
      "name": "a",
      "type": "int"
    }
  ]
}

 

and a writer record schema with an optional int (union of int and null) field a:

{
  "type": "record",
  "name": "Record1",
  "fields": [
    {
      "name": "a",
      "type": ["null", "int"],
      "default": "null"
    }
  ]
} 

 

I would expect to get the follow message and location on invoking get_compatibility(reader, writer):

message:  "reader type: int not compatible with writer type: null"
location: "/fields/0/type/0" 

 

Instead, we currently get:

message:  "reader type: int not compatible with writer type: null"
location: "/" 

 

losing all location information.