Add rename_all for union types

[banool]

I've been making a lot of issues lately sorry hahahh.

Imagine I have a struct like this:

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Union)]
#[serde(tag = "type", rename_all = "snake_case")]
#[oai(one_of, discriminator_name = "type")]
pub enum Transaction {
    PendingTransaction(PendingTransaction),
    StateCheckpointTransaction(StateCheckpointTransaction),
}

As it is now, the type value in the response will for example be PendingTransaction. However, if you try to deserialize that response using this struct + serde, it fails, because it expects the type field to be in snake case.

I have to have this unfortunately since I'm migrating a codebase to Poem and I still need the old serialization to work.

Would it be possible to add rename_all to unions to uniformly rename the mapping?

So instead of this:

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Union)]
#[serde(tag = "type", rename_all = "snake_case")]
#[oai(one_of, discriminator_name = "type")]
pub enum Transaction {
    #[oai(mapping = "pending_transaction")]
    PendingTransaction(PendingTransaction),
    #[oai(mapping = "state_checkpoint_transaction")]
    StateCheckpointTransaction(StateCheckpointTransaction),
}

I just do this:

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Union)]
#[serde(tag = "type", rename_all = "snake_case")]
#[oai(one_of, discriminator_name = "type", rename_all = "snake_case")]
pub enum Transaction {
    PendingTransaction(PendingTransaction),
    StateCheckpointTransaction(StateCheckpointTransaction),
}

Thanks a lot!!

[banool]

Awesome thanks a lot!!