refactor: remove async_trait crate due to increased MSRV

Cargo.toml

@@ -28,10 +28,6 @@ atrium-xrpc = { version = "0.11.4", path = "atrium-xrpc" }
 atrium-xrpc-client = { version = "0.5.7", path = "atrium-xrpc-client" }
 bsky-sdk = { version = "0.1.10", path = "bsky-sdk" }
 
-# async in traits
-# Can be removed once MSRV is at least 1.75.0.
-async-trait = "0.1.80"
-
 # DAG-CBOR codec
 ipld-core = { version = "0.4.1", default-features = false, features = ["std"] }
 serde_ipld_dagcbor = { version = "0.6.0", default-features = false, features = ["std"] }
@@ -76,3 +72,6 @@ mockito = "1.4"
 # WebAssembly
 wasm-bindgen-test = "0.3.41"
 bumpalo = "~3.14.0"
+
+# Code generation
+trait-variant = "0.1.2"

atrium-api/Cargo.toml

@@ -13,7 +13,6 @@ keywords.workspace = true
 
 [dependencies]
 atrium-xrpc.workspace = true
-async-trait.workspace = true
 chrono = { workspace = true, features = ["serde"] }
 http.workspace = true
 ipld-core = { workspace = true, features = ["serde"] }
@@ -24,6 +23,7 @@ serde_bytes.workspace = true
 serde_json.workspace = true
 thiserror.workspace = true
 tokio = { workspace = true, optional = true }
+trait-variant.workspace = true
 
 [features]
 default = ["agent", "bluesky"]

atrium-api/src/agent.rs

@@ -168,7 +168,6 @@ mod tests {
     use crate::com::atproto::server::create_session::OutputData;
     use crate::did_doc::{DidDocument, Service, VerificationMethod};
     use crate::types::TryIntoUnknown;
-    use async_trait::async_trait;
     use atrium_xrpc::HttpClient;
     use http::{HeaderMap, HeaderName, HeaderValue, Request, Response};
     use std::collections::HashMap;
@@ -189,8 +188,6 @@ mod tests {
         headers: Arc<RwLock<Vec<HeaderMap<HeaderValue>>>>,
     }
 
-    #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-    #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
     impl HttpClient for MockClient {
         async fn send_http(
             &self,

atrium-api/src/agent/inner.rs

@@ -2,7 +2,6 @@ use super::{Session, SessionStore};
 use crate::did_doc::DidDocument;
 use crate::types::string::Did;
 use crate::types::TryFromUnknown;
-use async_trait::async_trait;
 use atrium_xrpc::error::{Error, Result, XrpcErrorKind};
 use atrium_xrpc::{HttpClient, OutputDataOrBytes, XrpcClient, XrpcRequest};
 use http::{Method, Request, Response, Uri};
@@ -51,8 +50,6 @@ impl<S, T> Clone for WrapperClient<S, T> {
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl<S, T> HttpClient for WrapperClient<S, T>
 where
     S: Send + Sync,
@@ -67,8 +64,6 @@ where
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl<S, T> XrpcClient for WrapperClient<S, T>
 where
     S: SessionStore + Send + Sync,
@@ -231,8 +226,6 @@ where
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl<S, T> HttpClient for Client<S, T>
 where
     S: Send + Sync,
@@ -247,8 +240,6 @@ where
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl<S, T> XrpcClient for Client<S, T>
 where
     S: SessionStore + Send + Sync,
@@ -321,8 +312,6 @@ impl<S> Store<S> {
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl<S> SessionStore for Store<S>
 where
     S: SessionStore + Send + Sync,

atrium-api/src/agent/store.rs

@@ -1,16 +1,16 @@
 mod memory;
 
+use std::future::Future;
+
 pub use self::memory::MemorySessionStore;
 pub(crate) use super::Session;
-use async_trait::async_trait;
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+#[cfg_attr(not(target_arch = "wasm32"), trait_variant::make(Send))]
 pub trait SessionStore {
     #[must_use]
-    async fn get_session(&self) -> Option<Session>;
+    fn get_session(&self) -> impl Future<Output = Option<Session>>;
     #[must_use]
-    async fn set_session(&self, session: Session);
+    fn set_session(&self, session: Session) -> impl Future<Output = ()>;
     #[must_use]
-    async fn clear_session(&self);
+    fn clear_session(&self) -> impl Future<Output = ()>;
 }

atrium-api/src/agent/store/memory.rs

@@ -1,5 +1,4 @@
 use super::{Session, SessionStore};
-use async_trait::async_trait;
 use std::sync::Arc;
 use tokio::sync::RwLock;
 
@@ -8,8 +7,6 @@ pub struct MemorySessionStore {
     session: Arc<RwLock<Option<Session>>>,
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl SessionStore for MemorySessionStore {
     async fn get_session(&self) -> Option<Session> {
         self.session.read().await.clone()

atrium-xrpc-client/Cargo.toml

@@ -12,7 +12,6 @@ license.workspace = true
 keywords.workspace = true
 
 [dependencies]
-async-trait.workspace = true
 atrium-xrpc.workspace = true
 isahc = { workspace = true, optional = true }
 reqwest = { workspace = true, optional = true }

atrium-xrpc-client/src/isahc.rs

@@ -1,5 +1,4 @@
 #![doc = "XrpcClient implementation for [isahc]"]
-use async_trait::async_trait;
 use atrium_xrpc::http::{Request, Response};
 use atrium_xrpc::{HttpClient, XrpcClient};
 use isahc::{AsyncReadResponseExt, HttpClient as Client};
@@ -52,7 +51,6 @@ impl IsahcClientBuilder {
     }
 }
 
-#[async_trait]
 impl HttpClient for IsahcClient {
     async fn send_http(
         &self,

atrium-xrpc-client/src/reqwest.rs

@@ -1,5 +1,4 @@
 #![doc = "XrpcClient implementation for [reqwest]"]
-use async_trait::async_trait;
 use atrium_xrpc::http::{Request, Response};
 use atrium_xrpc::{HttpClient, XrpcClient};
 use reqwest::Client;
@@ -48,8 +47,6 @@ impl ReqwestClientBuilder {
     }
 }
 
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 impl HttpClient for ReqwestClient {
     async fn send_http(
         &self,

atrium-xrpc/Cargo.toml

@@ -12,12 +12,12 @@ license.workspace = true
 keywords.workspace = true
 
 [dependencies]
-async-trait.workspace = true
 http.workspace = true
 serde = { workspace = true, features = ["derive"] }
 serde_html_form.workspace = true
 serde_json.workspace = true
 thiserror.workspace = true
+trait-variant.workspace = true
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["macros", "rt"] }

atrium-xrpc/src/lib.rs

@@ -13,7 +13,6 @@ mod tests {
     use super::*;
     use crate::error::{XrpcError, XrpcErrorKind};
     use crate::{HttpClient, XrpcClient};
-    use async_trait::async_trait;
     use http::{Request, Response};
     #[cfg(target_arch = "wasm32")]
     use wasm_bindgen_test::*;
@@ -24,8 +23,6 @@ mod tests {
         body: Vec<u8>,
     }
 
-    #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-    #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
     impl HttpClient for DummyClient {
         async fn send_http(
             &self,