Convert contract::deploy to async (#388)

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

examples/contract.rs

@@ -23,7 +23,6 @@ async fn main() -> web3::contract::Result<()> {
             (U256::from(1_000_000_u64), "My Token".to_owned(), 3u64, "MT".to_owned()),
             my_account,
         )
-        .expect("Correct parameters are passed to the constructor.")
         .await?;
 
     let result = contract.query("balanceOf", (my_account,), None, Options::default(), None);

examples/contract_log_filter.rs

@@ -18,7 +18,7 @@ async fn main() -> web3::contract::Result<()> {
         .confirmations(1)
         .poll_interval(time::Duration::from_secs(10))
         .options(Options::with(|opt| opt.gas = Some(3_000_000.into())))
-        .execute(bytecode, (), accounts[0])?
+        .execute(bytecode, (), accounts[0])
         .await?;
 
     println!("contract deployed at: {}", contract.address());

examples/contract_log_pubsub.rs

@@ -18,7 +18,7 @@ async fn main() -> web3::contract::Result<()> {
         .confirmations(1)
         .poll_interval(time::Duration::from_secs(10))
         .options(Options::with(|opt| opt.gas = Some(3_000_000.into())))
-        .execute(bytecode, (), accounts[0])?;
+        .execute(bytecode, (), accounts[0]);
     let contract = contract.await?;
     println!("contract deployed at: {}", contract.address());
 

examples/contract_storage.rs

@@ -23,7 +23,7 @@ async fn main() -> web3::contract::Result<()> {
         .confirmations(1)
         .poll_interval(time::Duration::from_secs(10))
         .options(Options::with(|opt| opt.gas = Some(3_000_000.into())))
-        .execute(bytecode, (), accounts[0])?
+        .execute(bytecode, (), accounts[0])
         .await?;
 
     println!("Deployed at: {}", contract.address());

src/contract/deploy.rs

@@ -1,13 +1,8 @@
 //! Contract deployment utilities
 
-use ethabi;
-use futures::{
-    task::{Context, Poll},
-    Future, FutureExt, TryFutureExt,
-};
+use futures::{Future, TryFutureExt};
 use rustc_hex::{FromHex, ToHex};
 use std::collections::HashMap;
-use std::pin::Pin;
 use std::time;
 
 use crate::api::{Eth, Namespace};
@@ -51,7 +46,7 @@ impl<T: Transport> Builder<T> {
     }
 
     /// Execute deployment passing code and contructor parameters.
-    pub fn execute<P, V>(self, code: V, params: P, from: Address) -> Result<PendingContract<T>, ethabi::Error>
+    pub async fn execute<P, V>(self, code: V, params: P, from: Address) -> Result<Contract<T>, Error>
     where
         P: Tokenize,
         V: AsRef<str>,
@@ -63,20 +58,21 @@ impl<T: Transport> Builder<T> {
         self.do_execute(code, params, from, move |tx| {
             confirm::send_transaction_with_confirmation(transport, tx, poll_interval, confirmations)
         })
+        .await
     }
-    /// Execute deployment passing code and contructor parameters.
+    /// Execute deployment passing code and constructor parameters.
     ///
     /// Unlike the above `execute`, this method uses
     /// `sign_raw_transaction_with_confirmation` instead of
     /// `sign_transaction_with_confirmation`, which requires the account from
     /// which the transaction is sent to be unlocked.
-    pub fn sign_and_execute<P, V>(
+    pub async fn sign_and_execute<P, V>(
         self,
         code: V,
         params: P,
         from: Address,
         password: &str,
-    ) -> Result<PendingContract<T, impl Future<Output = error::Result<TransactionReceipt>>>, ethabi::Error>
+    ) -> Result<Contract<T>, Error>
     where
         P: Tokenize,
         V: AsRef<str>,
@@ -97,15 +93,16 @@ impl<T: Transport> Builder<T> {
                     )
                 })
         })
+        .await
     }
 
-    fn do_execute<P, V, Ft>(
+    async fn do_execute<P, V, Ft>(
         self,
         code: V,
         params: P,
         from: Address,
         send: impl FnOnce(TransactionRequest) -> Ft,
-    ) -> Result<PendingContract<T, Ft>, ethabi::Error>
+    ) -> Result<Contract<T>, Error>
     where
         P: Tokenize,
         V: AsRef<str>,
@@ -119,9 +116,9 @@ impl<T: Transport> Builder<T> {
 
         for (lib, address) in self.linker {
             if lib.len() > 38 {
-                return Err(ethabi::Error::Other(
+                return Err(Error::Abi(ethabi::Error::Other(
                     "The library name should be under 39 characters.".into(),
-                ));
+                )));
             }
             let replace = format!("__{:_<38}", lib); // This makes the required width 38 characters and will pad with `_` to match it.
             let address: String = address.as_ref().to_hex();
@@ -133,7 +130,9 @@ impl<T: Transport> Builder<T> {
         let params = params.into_tokens();
         let data = match (abi.constructor(), params.is_empty()) {
             (None, false) => {
-                return Err(ethabi::Error::Other("Constructor is not defined in the ABI.".into()));
+                return Err(Error::Abi(ethabi::Error::Other(
+                    "Constructor is not defined in the ABI.".into(),
+                )));
             }
             (None, true) => code,
             (Some(constructor), _) => constructor.encode_input(code, &params)?,
@@ -149,48 +148,16 @@ impl<T: Transport> Builder<T> {
             data: Some(Bytes(data)),
             condition: options.condition,
         };
-
-        let waiting = send(tx);
-
-        Ok(PendingContract {
-            eth: Some(eth),
-            abi: Some(abi),
-            waiting,
-        })
-    }
-}
-
-/// Contract being deployed.
-pub struct PendingContract<
-    T: Transport,
-    F: Future<Output = error::Result<TransactionReceipt>> = confirm::SendTransactionWithConfirmation<T>,
-> {
-    eth: Option<Eth<T>>,
-    abi: Option<ethabi::Contract>,
-    waiting: F,
-}
-
-impl<T, F> Future for PendingContract<T, F>
-where
-    F: Future<Output = error::Result<TransactionReceipt>> + Unpin,
-    T: Transport,
-{
-    type Output = Result<Contract<T>, Error>;
-
-    fn poll(mut self: Pin<&mut Self>, ctx: &mut Context) -> Poll<Self::Output> {
-        let receipt = ready!(self.waiting.poll_unpin(ctx))?;
-        let eth = self.eth.take().expect("future polled after ready; qed");
-        let abi = self.abi.take().expect("future polled after ready; qed");
-
-        Poll::Ready(match receipt.status {
+        let receipt = send(tx).await?;
+        match receipt.status {
             Some(status) if status == 0.into() => Err(Error::ContractDeploymentFailure(receipt.transaction_hash)),
             // If the `status` field is not present we use the presence of `contract_address` to
             // determine if deployment was successfull.
             _ => match receipt.contract_address {
                 Some(address) => Ok(Contract::new(eth, address, abi)),
                 None => Err(Error::ContractDeploymentFailure(receipt.transaction_hash)),
             },
-        })
+        }
     }
 }
 
@@ -243,10 +210,9 @@ mod tests {
                         "0x01020304",
                         (U256::from(1_000_000), "My Token".to_owned(), 3u64, "MT".to_owned()),
                         Address::from_low_u64_be(5),
-                    )
-                    .unwrap(),
+                    ),
             )
-            .unwrap();
+            .unwrap()
         };
 
         // then
@@ -303,7 +269,7 @@ mod tests {
         let lib_address;
         {
             let builder = Contract::deploy(api::Eth::new(&transport), &lib_abi).unwrap();
-            lib_address = futures::executor::block_on(builder.execute(lib_code, (), Address::zero()).unwrap())
+            lib_address = futures::executor::block_on(builder.execute(lib_code, (), Address::zero()))
                 .unwrap()
                 .address();
         }
@@ -331,7 +297,7 @@ mod tests {
                 linker
             })
             .unwrap();
-            let _ = futures::executor::block_on(builder.execute(main_code, (), Address::zero()).unwrap()).unwrap();
+            let _ = futures::executor::block_on(builder.execute(main_code, (), Address::zero())).unwrap();
         }
 
         transport.assert_request("eth_sendTransaction", &[

src/contract/error.rs

@@ -41,6 +41,9 @@ pub mod deploy {
     /// Contract deployment error.
     #[derive(Debug, Display, From)]
     pub enum Error {
+        /// eth abi error
+        #[display(fmt = "Abi error: {}", _0)]
+        Abi(ethabi::Error),
         /// Rpc error
         #[display(fmt = "Api error: {}", _0)]
         Api(ApiError),
@@ -52,6 +55,7 @@ pub mod deploy {
     impl std::error::Error for Error {
         fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
             match *self {
+                Error::Abi(ref e) => Some(e),
                 Error::Api(ref e) => Some(e),
                 Error::ContractDeploymentFailure(_) => None,
             }