Make ContractCall IntoFuture implement Send (#2083)

* fix(contracts): Add a failing test showing that ContractCall IntoFuture is not Send

* fix(contracts): Add Send bound for IntoFuture implementation of ContractCall

* chore: update CHAGELOG

* chore: fmt

---------

Co-authored-by: Georgios Konstantopoulos <me@gakonst.com>

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Unreleased
 
+- Add a `Send` bound to the `IntoFuture` implementation of `ContractCall` [#2083](https://github.com/gakonst/ethers-rs/pull/2083)
 - Bump [`svm-rs`](https://github.com/roynalnaruto/svm-rs) dependency to fix conflicts with Rust Crytpo packages [#2051](https://github.com/gakonst/ethers-rs/pull/2051)
 - Avoid unnecessary allocations in `utils` [#2046](https://github.com/gakonst/ethers-rs/pull/2046)
 - Add abigen support for hardhat generated bytecode json format [#2012](https://github.com/gakonst/ethers-rs/pull/2012)

ethers-contract/src/call.rs

@@ -225,10 +225,10 @@ impl<M, D> IntoFuture for ContractCall<M, D>
 where
     Self: 'static,
     M: Middleware,
-    D: Detokenize,
+    D: Detokenize + Send + Sync,
 {
     type Output = Result<D, ContractError<M>>;
-    type IntoFuture = Pin<Box<dyn Future<Output = Self::Output>>>;
+    type IntoFuture = Pin<Box<dyn Future<Output = Self::Output> + Send>>;
 
     fn into_future(self) -> Self::IntoFuture {
         Box::pin(async move { self.call().await })

ethers-contract/tests/it/contract_call.rs

@@ -0,0 +1,21 @@
+use ethers_contract_derive::abigen;
+use ethers_core::abi::Address;
+use ethers_providers::Provider;
+use std::{
+    future::{Future, IntoFuture},
+    sync::Arc,
+};
+
+#[tokio::test]
+async fn contract_call_into_future_is_send() {
+    abigen!(DsProxyFactory, "ethers-middleware/contracts/DsProxyFactory.json");
+    let (provider, _) = Provider::mocked();
+    let client = Arc::new(provider);
+    let contract = DsProxyFactory::new(Address::zero(), client);
+
+    fn is_send<T: Future + Send + 'static>(future: T) -> bool {
+        true
+    }
+
+    assert!(is_send(contract.cache().into_future()));
+}

ethers-contract/tests/it/main.rs

@@ -6,5 +6,6 @@ pub(crate) mod common;
 mod console;
 #[cfg(feature = "abigen")]
 mod contract;
+mod contract_call;
 
 fn main() {}