abuse Deref for using provider methods in the Client

examples/local_signer.rs

@@ -13,10 +13,8 @@ async fn main() -> Result<(), failure::Error> {
     )?
     .connect(&provider);
 
-    // get the account's nonce
-    let nonce = provider
-        .get_transaction_count(client.signer.address, None)
-        .await?;
+    // get the account's nonce (we abuse the Deref to access the provider's functions)
+    let nonce = client.get_transaction_count(client.address(), None).await?;
 
     // craft the transaction
     let tx = UnsignedTransaction {
@@ -29,7 +27,7 @@ async fn main() -> Result<(), failure::Error> {
     };
 
     // send it!
-    let tx = client.send_transaction(tx).await?;
+    let tx = client.sign_and_send_transaction(tx).await?;
 
     // get the mined tx
     let tx = client.get_transaction(tx.hash).await?;

src/providers/mod.rs

@@ -7,7 +7,7 @@ mod http;
 
 use crate::{
     signers::{Client, Signer},
-    types::{Address, BlockNumber, Bytes, Transaction, TransactionRequest, TxHash, U256},
+    types::{Address, BlockNumber, Transaction, TransactionRequest, TxHash, U256},
     utils,
 };
 
@@ -46,10 +46,12 @@ impl<P: JsonRpcClient> Provider<P> {
         }
     }
 
+    /// Gets the latest block number via the `eth_BlockNumber` API
     pub async fn get_block_number(&self) -> Result<U256, P::Error> {
         self.0.request("eth_blockNumber", None::<()>).await
     }
 
+    /// Gets the transaction which matches the provided hash via the `eth_getTransactionByHash` API
     pub async fn get_transaction<T: Send + Sync + Into<TxHash>>(
         &self,
         hash: T,
@@ -58,12 +60,14 @@ impl<P: JsonRpcClient> Provider<P> {
         self.0.request("eth_getTransactionByHash", Some(hash)).await
     }
 
+    /// Broadcasts the transaction request via the `eth_sendTransaction` API
     pub async fn send_transaction(&self, tx: TransactionRequest) -> Result<TxHash, P::Error> {
         self.0.request("eth_sendTransaction", Some(tx)).await
     }
 
-    pub async fn send_raw_transaction(&self, rlp: &Bytes) -> Result<TxHash, P::Error> {
-        let rlp = utils::serialize(&rlp);
+    /// Broadcasts a raw RLP encoded transaction via the `eth_sendRawTransaction` API
+    pub async fn send_raw_transaction(&self, tx: &Transaction) -> Result<TxHash, P::Error> {
+        let rlp = utils::serialize(&tx.rlp());
         self.0.request("eth_sendRawTransaction", Some(rlp)).await
     }
 

src/signers/client.rs

@@ -1,31 +1,45 @@
 use crate::{
     providers::{JsonRpcClient, Provider},
     signers::Signer,
-    types::{Transaction, TxHash, UnsignedTransaction},
+    types::{Address, Transaction, UnsignedTransaction},
 };
 
+use std::ops::Deref;
+
 #[derive(Clone, Debug)]
 pub struct Client<'a, S, P> {
-    pub provider: &'a Provider<P>,
-    pub signer: S,
+    pub(crate) provider: &'a Provider<P>,
+    pub(crate) signer: S,
 }
 
 impl<'a, S: Signer, P: JsonRpcClient> Client<'a, S, P> {
-    pub async fn send_transaction(&self, tx: UnsignedTransaction) -> Result<Transaction, P::Error> {
+    /// Signs the transaction and then broadcasts its RLP encoding via the `eth_sendRawTransaction`
+    /// API
+    pub async fn sign_and_send_transaction(
+        &self,
+        tx: UnsignedTransaction,
+    ) -> Result<Transaction, P::Error> {
         // sign the transaction
         let signed_tx = self.signer.sign_transaction(tx.clone());
 
         // broadcast it
-        self.provider.send_raw_transaction(&signed_tx.rlp()).await?;
+        self.provider.send_raw_transaction(&signed_tx).await?;
 
         Ok(signed_tx)
     }
 
-    // TODO: Forward all other calls to the provider
-    pub async fn get_transaction<T: Send + Sync + Into<TxHash>>(
-        &self,
-        hash: T,
-    ) -> Result<Transaction, P::Error> {
-        self.provider.get_transaction(hash).await
+    pub fn address(&self) -> Address {
+        self.signer.address()
+    }
+}
+
+// Abuse Deref to use the Provider's methods without re-writing everything.
+// This is an anti-pattern and should not be encouraged, but this improves the UX while
+// keeping the LoC low
+impl<'a, S, P> Deref for Client<'a, S, P> {
+    type Target = &'a Provider<P>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.provider
     }
 }

src/signers/mod.rs

@@ -9,7 +9,7 @@ pub use wallet::Wallet;
 mod client;
 pub(crate) use client::Client;
 
-use crate::types::{Signature, Transaction, UnsignedTransaction};
+use crate::types::{Address, Signature, Transaction, UnsignedTransaction};
 
 /// Trait for signing transactions and messages
 ///
@@ -20,4 +20,7 @@ pub trait Signer {
 
     /// Signs the transaction
     fn sign_transaction(&self, message: UnsignedTransaction) -> Transaction;
+
+    /// Returns the signer's Ethereum Address
+    fn address(&self) -> Address;
 }

src/signers/wallet.rs

@@ -24,6 +24,10 @@ impl<'a, N: Network> Signer for Wallet<N> {
     fn sign_transaction(&self, tx: UnsignedTransaction) -> Transaction {
         self.private_key.sign_transaction(tx, N::CHAIN_ID)
     }
+
+    fn address(&self) -> Address {
+        self.address
+    }
 }
 
 impl<N: Network> Wallet<N> {