[AVRO-3842] [Python] Cannot write a record in a union of [map, record]

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.12.0, 1.11.2
• Component/s: python

Environment

Python 3.10.3
avro 1.11 and 1.12

• Assignee: Unassigned
• Reporter: Steve Stagg
• Created: 24/Aug/23 10:38
• Updated: 24/Aug/23 10:38

Description

The following script raises a validation exception because the map schema .validate doesn't check the value types, so union schema picks the wrong path, and then raises:

from io import BytesIO
import json
import avro.io
import avro.schema

SCHEMA = [
    {"type": "map", "values": "int"},
    {
        "type": "record",
        "name": "A",
        "fields": [
            {"aliases": [], "type": "string", "name": "x"},
        ],
    },
]

datum = {'x': 'Hello'}

if __name__ == '__main__':
    sch = avro.schema.parse(json.dumps(SCHEMA))
    buf = BytesIO()
    encoder = avro.io.BinaryEncoder(buf)
    writer = avro.io.DatumWriter(sch)
    encoded = writer.write(datum, encoder)