Ignore some fields in untagged enum varints

[g302ge]

I have an enum struct as this :

#[derive(Debug, Deserialize)]
#[serde(untagged)]
pub enum Message {
        Price {
             min: BigDecimal,
             max: BigDecimal,
        }
}

And I have implemented a self-defined serializer for this enum target to insert a new field into the final str. look like this

{
      "inserted": "I'm inserted",
      "max": "0.1",
      "min": "0.1",
}

But in this test case I got an error

fn test_de_after_ser() {
        let message = Message::Price{
                max: BigDecimal::from_str("0.1").unwrap(),
                min: BigDeciaml::from_str("0.1").unwrap(),
        };
        let serialized = serde_json::to_string(&message).unwrap();
        let deserialized: Message = serde_json::from_str(&serialized).unwrap();
}

The runtime complain that could not match any varints in enum, So if there some approach to fix this problem. If not, should we introduce a new attributed like this

#[derive(Debug, Deserialize)]
#[serde(untagged)]
#[serde(ignore = "inserted")]
pub enum Message {
        Price {
             min: BigDecimal,
             max: BigDecimal,
        }
}

The attributed #[serde(ignore = "inserted")] semantic is that this contianer should ignore the fields defined in ignore attributed when deserializing from a serialized item.

[jonasbb]

Extra fields get ignored and it works with other types instead of BigDecimal. https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=3cf05e785f0184c3556cce87683eba55 BigDecimal probably doesn't support deserialization from strings. You can get better error messages if you remove the untagged attribute.

[g302ge]

Extra fields get ignored and it works with other types instead of BigDecimal. https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=3cf05e785f0184c3556cce87683eba55 BigDecimal probably doesn't support deserialization from strings. You can get better error messages if you remove the untagged attribute.

But I found that the BigDecimal implemente the Deserialize trait, please tell me why the bigdecimal::BigDecimal could not be ignored ? Maybe I could do some patch for the bigdecimal crate for more wild usage. thx for your reply

[dtolnay]

I was not able to reproduce this. It deserialized successfully. Assuming fixed in bigdecimal.