Nullable Arrays

[kevanm]

Hi,

I am just getting started and having a hard time creating avro schemas with nullable lists.

{
  "type": "record",
  "name": "Test",
  "fields":[{
    "name":"test_field_1",
    "type":"long"
  },
    {
      "name":"subrecord",
      "type":[{
        "type":"record",
        "name":"subrecord_type",
        "fields":[{
          "name":"field_1",
          "type":"long"
        }
        ]
      },
        "null"
      ]
    },
    {
      "name":"simple_array",
      "type":["null",
        {
          "type":"array",
          "items":"string"
        }
      ],
      "default":null
    }
  ]
}

Generates

public class subrecord_type
{
    public long field_1 { get; set; }
}

public class Test
{
    public long test_field_1 { get; set; }
    public subrecord_type subrecord { get; set; }
    public IEnumerable<string> simple_array { get; set; }
}

But that class does generate avro schema with a nullable simple_array.

I have found success with the cli flag --nullable-references all. Is there something I can do in setup/config of SetAvroValueSerializer that is equivalent to --nullable-references all? Thanks!

[dstelljes]

You should be able to make it work by passing a custom SchemaBuilder to AsyncSchemaRegistrySerializer:

var producer = new ProducerBuilder<SomeKey, SomeValue>(producerConfig)
    .SetValueSerializer(new AsyncSchemaRegistrySerializer(
        registryConfig,
        registerAutomatically: AutomaticRegistrationBehavior.Always,
        schemaBuilder: new SchemaBuilder(nullableReferenceTypeBehavior: NullableReferenceTypeBehavior.All)))
    .Build();

Alternatively, you could enable nullable reference types; the default behavior takes those annotations into account.

[kevanm]

Great thank you that was exactly what I was looking for.