SchemaNotFoundInUnion with simple serialization

[tkubicz]

Hello,

I've encountered an issue while trying to serialize a simple struct with union type into avro recrod.

{
    "name": "Reference",
    "type": "record",
    "fields": [
        {
            "name": "feedReference",
            "type": [
                "null",
                {
                    "name": "FeedReference",
                    "type": "record",
                    "fields": [
                        {
                            "name": "instance",
                            "type": "string"
                        },
                        {
                            "name": "provider",
                            "type": "string"
                        }
                    ]
                }
            ],
            "default": null
        }
    ]
}

Simple rust code to reproduce the issue:

#[derive(Serialize, Deserialize)]
    struct Reference {
        #[serde(rename = "feedReference")]
        pub feed_reference: Option<FeedReference>,
    }

    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
    pub struct FeedReference {
        pub instance: String,
        pub provider: String,
    }

    impl Default for FeedReference {
        fn default() -> FeedReference {
            FeedReference {
                instance: String::default(),
                provider: String::default(),
            }
        }
    }

    #[test]
    fn validate_schema_avrow() {
        let reference = Reference {
            feed_reference: Some(FeedReference::default()),
        };

        let schema_str = std::fs::read_to_string("avro/feed_reference.avsc").unwrap();
        let schema = Schema::from_str(&schema_str).unwrap();
        let mut writer = Writer::new(&schema, vec![]).unwrap();
        writer.serialize(reference).unwrap();
    }

And the result:

thread 'test::validate_schema_avrow' panicked at 'called `Result::unwrap()` on an `Err` value: SchemaNotFoundInUnion', crates/platform_content/src/lib.rs:36:37
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
test test::validate_schema_avrow ... FAILED

The funny thing is, that when I pass None into the feed_reference field, struct seems to serialize correctly.
The same schema and struct serializes just fine using e.g avro-rs.

[creativcoder]

Hi @tkubicz

Thanks for reporting this!

Looks like the union schema resolution method, did not account for implicitly defined named schemas.
This has been fixed with #7. Will do a point release post merge.