URI extractor fails if data struct is defined with a tuple

[llamicron]

If the struct that implements StateData and StaticResponseExtender used for extracting variables out of the URI is defined with a tuple, the route returns with a code 400.

Example

#[derive(Resource, serde::Deserialize)]
#[resource(update_device)]
pub struct DeviceResource;

#[derive(Debug, Deserialize, Clone, StateData, StaticResponseExtender)]
pub struct DeviceID(String); // This compiles fine, but the handler returns 400

// Replacing the above with this makes the handler return ok
// #[derive(Debug, Deserialize, Clone, StateData, StaticResponseExtender)]
// pub struct DeviceID {
//     id: String
// }

#[endpoint(
    uri = "update/:id",
    method = "Method::GET",
    params = false,
    body = false
)]
pub async fn update_device(id: DeviceID) -> Response {
    log::info!("Got id: `{:?}`", id);
    Response::no_content()
}

// Test used
// This will fail when the struct is defined as above,
// but it passes when the struct is defined with the `id` field
#[test]
    fn test_device_update() {
        let test_server = TestServer::new(router()).unwrap();
        let response = test_server
            .client()
			.get("http://localhost:7878/device/update/omega1")
            .perform()
            .unwrap();

        assert_eq!(response.status(), StatusCode::NO_CONTENT);
    }

I'm not sure if this is intentional, but it's not very clear why it fails and if that's intended behavior or not.

[msrd0]

Try adding #[serde(transparent)] to the tuple struct. Does that fix your issue?

Sorry, this will likely not work since you're using a custom endpoint.

[msrd0]

The struct you're defining is being used as a gotham PathExtractor which is automatically provided for all types that are Deserialize, StateData and StaticResponseExtender. When extracting a path, the deserialize implementation is provided with a map, in your case the equivalent of {"id": "omega1"}. If the deserialize implementation rejects this input, the route returns a 400. The problem is not your tuple struct but rather the auto-derived deserialize implementation for it.