client-api: Return 201 from update_device when a device is created.

The PUT /devices/{deviceId} response carries a `created` flag mapping to
201 on creation and 200 on update, hand-written because the response
macro fixes the status (MSC4190).

Signed-off-by: Jason Volk <jason@zemos.net>

Author: jevolk

crates/ruma-client-api/src/device/update_device.rs

@@ -11,7 +11,7 @@ pub mod v3 {
 
     use ruma_common::{
         OwnedDeviceId,
-        api::{auth_scheme::AccessToken, request, response},
+        api::{auth_scheme::AccessToken, request},
         metadata,
     };
 
@@ -42,9 +42,18 @@ pub mod v3 {
     }
 
     /// Response type for the `update_device` endpoint.
-    #[response]
-    #[derive(Default)]
-    pub struct Response {}
+    ///
+    /// The HTTP status reflects whether a device was created or merely updated:
+    /// an application service creating a device receives `201 Created`, any
+    /// other update receives `200 OK` (MSC4190). The body is empty in both
+    /// cases, so this is hand-written rather than generated by the `response`
+    /// macro, whose status is fixed.
+    #[derive(Clone, Debug, Default)]
+    #[cfg_attr(not(ruma_unstable_exhaustive_types), non_exhaustive)]
+    pub struct Response {
+        /// Whether a new device was created rather than an existing one updated.
+        pub created: bool,
+    }
 
     impl Request {
         /// Creates a new `Request` with the given device ID.
@@ -54,9 +63,54 @@ pub mod v3 {
     }
 
     impl Response {
-        /// Creates an empty `Response`.
+        /// Creates a `Response` for an updated device (`200 OK`).
         pub fn new() -> Self {
-            Self {}
+            Self { created: false }
+        }
+
+        /// Creates a `Response` for a newly created device (`201 Created`).
+        pub fn created() -> Self {
+            Self { created: true }
+        }
+    }
+
+    #[cfg(feature = "server")]
+    impl ruma_common::api::OutgoingResponse for Response {
+        fn try_into_http_response<T: Default + bytes::BufMut>(
+            self,
+        ) -> Result<http::Response<T>, ruma_common::api::error::IntoHttpError> {
+            let status =
+                if self.created { http::StatusCode::CREATED } else { http::StatusCode::OK };
+
+            let mut response = http::Response::builder()
+                .status(status)
+                .body(ruma_common::serde::slice_to_buf(b"{}"))?;
+
+            response
+                .headers_mut()
+                .insert(http::header::CONTENT_TYPE, ruma_common::http_headers::APPLICATION_JSON);
+
+            Ok(response)
+        }
+    }
+
+    #[cfg(feature = "client")]
+    impl ruma_common::api::IncomingResponse for Response {
+        type EndpointError = ruma_common::api::error::Error;
+
+        fn try_from_http_response<T: AsRef<[u8]>>(
+            response: http::Response<T>,
+        ) -> Result<Self, ruma_common::api::error::FromHttpResponseError<Self::EndpointError>>
+        {
+            if response.status().as_u16() >= 400 {
+                return Err(ruma_common::api::error::FromHttpResponseError::Server(
+                    <Self::EndpointError as ruma_common::api::EndpointError>::from_http_response(
+                        response,
+                    ),
+                ));
+            }
+
+            Ok(Self { created: response.status() == http::StatusCode::CREATED })
         }
     }
 }