async-graphql Renaming Fields

Cargo.toml

[package]
name = "async-graphql-issue"
version = "0.1.0"
authors = ["Oscar Beaumont <[email protected]>"]
edition = "2018"

[dependencies]
async-graphql = "2.8.5"
tokio = { version = "0.2.22", features = ["full"] }

main.rs

use async_graphql::{EmptyMutation, EmptySubscription, Object, SimpleObject};

#[derive(SimpleObject)]
#[graphql(rename_fields = "camelCase")]
pub struct User {
    pub id: String,
    pub first_name: String,
}

pub type Schema = async_graphql::Schema<QueryRoot, EmptyMutation, EmptySubscription>;

pub struct QueryRoot;

#[Object]
impl QueryRoot {
    async fn user(&self) -> User {
        User {
            id: "92ba0c2d-4b4e-4e29-91dd-8f96a078c3ff".to_string(),
            first_name: "Oscar".to_string(),
        }
    }
}

#[tokio::main]
async fn main() {
    let schema = Schema::new(QueryRoot, EmptyMutation, EmptySubscription);
    let query = "{ user { id, firstName } }";
    let result = schema.execute(query).await;
    println!("{}", result.data);
}