Merge pull request #20 from fraktalio/feature/async_fn_in_traits

`async fn` in Traits - a new `stable` feature of Rust 1.75

Author: idugalic

.github/workflows/build.yml

@@ -12,11 +12,21 @@ env:
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, windows-latest, macOS-latest ]
+        rust: [ stable, nightly ]
 
     steps:
+      - uses: hecrj/setup-rust-action@v2
+        with:
+          rust-version: ${{ matrix.rust }}
+
       - uses: actions/checkout@v4
+
       - name: Build
         run: cargo build --verbose
+
       - name: Run tests
         run: cargo test --verbose

.github/workflows/publish.yml

@@ -10,10 +10,19 @@ env:
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, windows-latest, macOS-latest ]
+        rust: [ stable, nightly ]
 
     steps:
+      - uses: hecrj/setup-rust-action@v2
+        with:
+          rust-version: ${{ matrix.rust }}
+
       - uses: actions/checkout@v4
+
       - name: Publish
         run: cargo publish --token ${CRATES_TOKEN}
         env:

Cargo.lock

@@ -1,16 +1,14 @@
 [package]
 name = "fmodel-rust"
-version = "0.6.1"
+version = "0.7.0"
 edition = "2021"
 description = "Accelerate development of compositional, safe, and ergonomic applications/information systems by effectively implementing Event Sourcing and CQRS patterns in Rust."
 license = "Apache-2.0"
 
 [dependencies]
-async-trait = "0.1.75"
 serde = {version = "1.0.193", features = ["derive"]}
 
 
 [dev-dependencies]
 derive_more = "0.99.17"
 tokio = { version = "1.35.1", features = ["rt", "rt-multi-thread", "macros"] }
-

Cargo.toml

@@ -1,7 +1,6 @@
+use std::future::Future;
 use std::marker::PhantomData;
 
-use async_trait::async_trait;
-
 use crate::decider::{Decider, EventComputation, StateComputation};
 use crate::saga::{ActionComputation, Saga};
 
@@ -13,16 +12,22 @@ use crate::saga::{ActionComputation, Saga};
 /// - `E` - Event
 /// - `Version` - Version/Offset/Sequence number
 /// - `Error` - Error
-#[async_trait]
 pub trait EventRepository<C, E, Version, Error> {
     /// Fetches current events, based on the command.
-    async fn fetch_events(&self, command: &C) -> Result<Vec<(E, Version)>, Error>;
+    /// Desugared `async fn fetch_events(&self, command: &C) -> Result<Vec<(E, Version)>, Error>;` to a normal `fn` that returns `impl Future`, and adds bound `Send`.
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn fetch_events(
+        &self,
+        command: &C,
+    ) -> impl Future<Output = Result<Vec<(E, Version)>, Error>> + Send;
     /// Saves events.
-    async fn save(
+    /// Desugared `async fn save(&self, events: &[E], latest_version: &Option<Version>) -> Result<Vec<(E, Version)>, Error>;` to a normal `fn` that returns `impl Future`, and adds bound `Send`
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn save(
         &self,
         events: &[E],
         latest_version: &Option<Version>,
-    ) -> Result<Vec<(E, Version)>, Error>;
+    ) -> impl Future<Output = Result<Vec<(E, Version)>, Error>> + Send;
 }
 
 /// Event Sourced Aggregate.
@@ -61,7 +66,6 @@ where
     }
 }
 
-#[async_trait]
 impl<C, S, E, Repository, Decider, Version, Error> EventRepository<C, E, Version, Error>
     for EventSourcedAggregate<C, S, E, Repository, Decider, Version, Error>
 where
@@ -129,12 +133,22 @@ where
 /// - `S` - State
 /// - `Version` - Version
 /// - `Error` - Error
-#[async_trait]
 pub trait StateRepository<C, S, Version, Error> {
     /// Fetches current state, based on the command.
-    async fn fetch_state(&self, command: &C) -> Result<Option<(S, Version)>, Error>;
+    /// Desugared `async fn fetch_state(&self, command: &C) -> Result<Option<(S, Version)>, Error>;` to a normal `fn` that returns `impl Future` and adds bound `Send`
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn fetch_state(
+        &self,
+        command: &C,
+    ) -> impl Future<Output = Result<Option<(S, Version)>, Error>> + Send;
     /// Saves state.
-    async fn save(&self, state: &S, version: &Option<Version>) -> Result<(S, Version), Error>;
+    /// Desugared `async fn save(&self, state: &S, version: &Option<Version>) -> Result<(S, Version), Error>;` to a normal `fn` that returns `impl Future` and adds bound `Send`
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn save(
+        &self,
+        state: &S,
+        version: &Option<Version>,
+    ) -> impl Future<Output = Result<(S, Version), Error>> + Send;
 }
 
 /// State Stored Aggregate.
@@ -173,7 +187,6 @@ where
     }
 }
 
-#[async_trait]
 impl<C, S, E, Repository, Decider, Version, Error> StateRepository<C, S, Version, Error>
     for StateStoredAggregate<C, S, E, Repository, Decider, Version, Error>
 where
@@ -281,7 +294,6 @@ where
     }
 }
 
-#[async_trait]
 impl<'a, C, S, E, Repository, Version, Error> StateRepository<C, S, Version, Error>
     for StateStoredOrchestratingAggregate<'a, C, S, E, Repository, Version, Error>
 where

src/aggregate.rs

@@ -1,7 +1,6 @@
+use std::future::Future;
 use std::marker::PhantomData;
 
-use async_trait::async_trait;
-
 use crate::view::ViewStateComputation;
 
 /// View State Repository trait
@@ -11,12 +10,15 @@ use crate::view::ViewStateComputation;
 /// - `E` - Event
 /// - `S` - State
 /// - `Error` - Error
-#[async_trait]
 pub trait ViewStateRepository<E, S, Error> {
     /// Fetches current state, based on the event.
-    async fn fetch_state(&self, event: &E) -> Result<Option<S>, Error>;
+    /// Desugared `async fn fetch_state(&self, event: &E) -> Result<Option<S>, Error>;` to a normal `fn` that returns `impl Future`, and adds bound `Send`.
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn fetch_state(&self, event: &E) -> impl Future<Output = Result<Option<S>, Error>> + Send;
     /// Saves the new state.
-    async fn save(&self, state: &S) -> Result<S, Error>;
+    /// Desugared `async fn save(&self, state: &S) -> Result<S, Error>;` to a normal `fn` that returns `impl Future`, and adds bound `Send`.
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn save(&self, state: &S) -> impl Future<Output = Result<S, Error>> + Send;
 }
 
 /// Materialized View.
@@ -53,7 +55,6 @@ where
     }
 }
 
-#[async_trait]
 impl<S, E, Repository, View, Error> ViewStateRepository<E, S, Error>
     for MaterializedView<S, E, Repository, View, Error>
 where

src/materialized_view.rs

@@ -1,7 +1,6 @@
+use std::future::Future;
 use std::marker::PhantomData;
 
-use async_trait::async_trait;
-
 use crate::saga::ActionComputation;
 
 /// Publishes the action/command to some external system.
@@ -10,10 +9,11 @@ use crate::saga::ActionComputation;
 ///
 /// - `A`. - action
 /// - `Error` - error
-#[async_trait]
 pub trait ActionPublisher<A, Error> {
     /// Publishes the action/command to some external system, returning either the actions that are successfully published or error.
-    async fn publish(&self, action: &[A]) -> Result<Vec<A>, Error>;
+    /// Desugared `async fn publish(&self, action: &[A]) -> Result<Vec<A>, Error>;` to a normal `fn` that returns `impl Future`, and adds bound `Send`.
+    /// You can freely move between the `async fn` and `-> impl Future` spelling in your traits and impls. This is true even when one form has a Send bound.
+    fn publish(&self, action: &[A]) -> impl Future<Output = Result<Vec<A>, Error>> + Send;
 }
 
 /// Saga Manager.
@@ -48,7 +48,6 @@ where
     }
 }
 
-#[async_trait]
 impl<A, AR, Publisher, Saga, Error> ActionPublisher<A, Error>
     for SagaManager<A, AR, Publisher, Saga, Error>
 where

src/saga_manager.rs

@@ -3,7 +3,6 @@ use std::error::Error;
 use std::sync::{Arc, Mutex};
 use std::thread;
 
-use async_trait::async_trait;
 use derive_more::Display;
 
 use fmodel_rust::aggregate::{
@@ -75,7 +74,6 @@ impl Id for (OrderState, ShipmentState) {
     }
 }
 /// Implementation of [EventRepository] for [InMemoryEventRepository] - infrastructure
-#[async_trait]
 impl
     EventRepository<
         Sum<OrderCommand, ShipmentCommand>,
@@ -133,7 +131,6 @@ impl InMemoryStateRepository {
 }
 
 // Implementation of [StateRepository] for [InMemoryOrderStateRepository]
-#[async_trait]
 impl
     StateRepository<
         Sum<OrderCommand, ShipmentCommand>,

tests/aggregate_combined_test.rs

@@ -3,7 +3,6 @@ use std::error::Error;
 use std::sync::{Arc, Mutex};
 use std::thread;
 
-use async_trait::async_trait;
 use derive_more::Display;
 
 use fmodel_rust::aggregate::{
@@ -44,7 +43,6 @@ impl InMemoryOrderEventRepository {
 }
 
 /// Implementation of [EventRepository] for [InMemoryOrderEventRepository] - infrastructure
-#[async_trait]
 impl EventRepository<OrderCommand, OrderEvent, i32, AggregateError>
     for InMemoryOrderEventRepository
 {
@@ -97,7 +95,6 @@ impl InMemoryOrderStateRepository {
 }
 
 // Implementation of [StateRepository] for [InMemoryOrderStateRepository]
-#[async_trait]
 impl StateRepository<OrderCommand, OrderState, i32, AggregateError>
     for InMemoryOrderStateRepository
 {

tests/aggregate_test.rs

@@ -3,7 +3,6 @@ use std::error::Error;
 use std::sync::{Arc, Mutex};
 use std::thread;
 
-use async_trait::async_trait;
 use derive_more::Display;
 
 use fmodel_rust::materialized_view::{MaterializedView, ViewStateRepository};
@@ -125,7 +124,6 @@ impl Id for (OrderViewState, ShipmentViewState) {
 }
 
 // Implementation of [ViewStateRepository] for [InMemoryViewOrderStateRepository]
-#[async_trait]
 impl
     ViewStateRepository<
         Sum<OrderEvent, ShipmentEvent>,