fix(signers): make wallet non-optional

ethers-core/src/utils/ganache.rs

@@ -1,4 +1,9 @@
-use std::process::{Child, Command};
+use std::{
+    process::{Child, Command},
+    time::Duration,
+};
+
+const SLEEP_TIME: Duration = Duration::from_secs(3);
 
 /// A ganache CLI instance. Will close the instance when dropped.
 ///
@@ -74,9 +79,7 @@ impl Ganache {
         let ganache_pid = cmd.spawn().expect("couldnt start ganache-cli");
 
         // wait a couple of seconds for ganache to boot up
-        // TODO: Change this to poll for `port`
-        let sleep_time = std::time::Duration::from_secs(2);
-        std::thread::sleep(sleep_time);
+        std::thread::sleep(SLEEP_TIME);
         GanacheInstance(ganache_pid)
     }
 }

ethers-providers/src/provider.rs

@@ -282,8 +282,12 @@ impl<P: JsonRpcClient> Provider<P> {
     }
 
     /// Signs data using a specific account. This account needs to be unlocked.
-    pub async fn sign(&self, data: &Bytes, from: &Address) -> Result<Signature, ProviderError> {
-        let data = utils::serialize(data);
+    pub async fn sign<T: Into<Bytes>>(
+        &self,
+        data: T,
+        from: &Address,
+    ) -> Result<Signature, ProviderError> {
+        let data = utils::serialize(&data.into());
         let from = utils::serialize(from);
         Ok(self
             .0

ethers-signers/src/client.rs

@@ -12,7 +12,7 @@ use thiserror::Error;
 #[derive(Clone, Debug)]
 /// A client provides an interface for signing and broadcasting locally signed transactions
 /// It Derefs to [`Provider`], which allows interacting with the Ethereum JSON-RPC provider
-/// via the same API. Sending transactions also supports using ENS as a receiver. If you will
+/// via the same API. Sending transactions also supports using [ENS](https://ens.domains/) as a receiver. If you will
 /// not be using a local signer, it is recommended to use a [`Provider`] instead.
 ///
 /// # Example
@@ -24,29 +24,35 @@ use thiserror::Error;
 /// use std::convert::TryFrom;
 ///
 /// # async fn foo() -> Result<(), Box<dyn std::error::Error>> {
-/// let mut client: Client<_, _> = Provider::<Http>::try_from("http://localhost:8545")
-///     .expect("could not instantiate HTTP Provider").into();
+/// let provider = Provider::<Http>::try_from("http://localhost:8545")
+///     .expect("could not instantiate HTTP Provider");
 ///
-/// // since it derefs to `Provider`, we can just call any of the JSON-RPC API methods
-/// let block = client.get_block(100u64).await?;
-///
-/// // calling `sign_message` and `send_transaction` will use the unlocked accounts
-/// // on the node.
-/// let signed_msg = client.sign_message(b"hello".to_vec()).await?;
-///
-/// let tx = TransactionRequest::pay("vitalik.eth", 100);
-/// let tx_hash = client.send_transaction(tx, None).await?;
-///
-/// // if we set a signer, signing of messages and transactions will be done locally
+/// // By default, signing of messages and transactions is done locally
 /// // (transactions will be broadcast via the eth_sendRawTransaction API)
 /// let wallet: Wallet = "380eb0f3d505f087e438eca80bc4df9a7faa24f868e69fc0440261a0fc0567dc"
 ///     .parse()
 ///     .unwrap();
 ///
-/// let client = client.with_signer(wallet);
+/// let mut client = Client::new(provider, wallet);
 ///
-/// let signed_msg2 = client.sign_message(b"hello".to_vec()).await?;
+/// // since it derefs to `Provider`, we can just call any of the JSON-RPC API methods
+/// let block = client.get_block(100u64).await?;
 ///
+/// // You can use the node's `eth_sign` and `eth_sendTransaction` calls by calling the
+/// // internal provider's method.
+/// let signed_msg = client.provider().sign(b"hello".to_vec(), &client.address()).await?;
+///
+/// let tx = TransactionRequest::pay("vitalik.eth", 100);
+/// let tx_hash = client.send_transaction(tx, None).await?;
+///
+/// // You can connect with other wallets at runtime via the `with_signer` function
+/// let wallet2: Wallet = "cd8c407233c0560f6de24bb2dc60a8b02335c959a1a17f749ce6c1ccf63d74a7"
+///     .parse()
+///     .unwrap();
+///
+/// let signed_msg2 = client.with_signer(wallet2).sign_message(b"hello".to_vec()).await?;
+///
+/// // This call will be made with `wallet2` since `with_signer` takes a mutable reference.
 /// let tx2 = TransactionRequest::new()
 ///     .to("0xd8da6bf26964af9d7eed9e03e53415d37aa96045".parse::<Address>()?)
 ///     .value(200);
@@ -57,23 +63,13 @@ use thiserror::Error;
 ///
 /// ```
 ///
-/// [`Provider`](../ethers_providers/struct.Provider.html)
+/// [`Provider`]: ../ethers_providers/struct.Provider.html
 pub struct Client<P, S> {
     pub(crate) provider: Provider<P>,
-    pub(crate) signer: Option<S>,
+    pub(crate) signer: S,
     pub(crate) address: Address,
 }
 
-impl<P, S> From<Provider<P>> for Client<P, S> {
-    fn from(provider: Provider<P>) -> Self {
-        Client {
-            provider,
-            signer: None,
-            address: Address::zero(),
-        }
-    }
-}
-
 #[derive(Debug, Error)]
 /// Error thrown when the client interacts with the blockchain
 pub enum ClientError {
@@ -96,18 +92,25 @@ where
     S: Signer,
     P: JsonRpcClient,
 {
+    /// Creates a new client from the provider and signer.
+    pub fn new(provider: Provider<P>, signer: S) -> Self {
+        let address = signer.address();
+        Client {
+            provider,
+            signer,
+            address,
+        }
+    }
+
     /// Signs a message with the internal signer, or if none is present it will make a call to
     /// the connected node's `eth_call` API.
     pub async fn sign_message<T: Into<Bytes>>(&self, msg: T) -> Result<Signature, ClientError> {
-        let msg = msg.into();
-        Ok(if let Some(ref signer) = self.signer {
-            signer.sign_message(msg)
-        } else {
-            self.provider.sign(&msg, &self.address).await?
-        })
+        Ok(self.signer.sign_message(msg.into()))
     }
 
-    /// Signs and broadcasts the transaction
+    /// Signs and broadcasts the transaction. The optional parameter `block` can be passed so that
+    /// gas cost and nonce calculations take it into account. For simple transactions this can be
+    /// left to `None`.
     pub async fn send_transaction(
         &self,
         mut tx: TransactionRequest,
@@ -123,19 +126,11 @@ where
             }
         }
 
-        // if there is no local signer, then the transaction should use the
-        // node's signer which should already be unlocked
-        let signer = if let Some(ref signer) = self.signer {
-            signer
-        } else {
-            return Ok(self.provider.send_transaction(tx).await?);
-        };
-
         // fill any missing fields
         self.fill_transaction(&mut tx, block).await?;
 
         // sign the transaction with the network
-        let signed_tx = signer.sign_transaction(tx).map_err(Into::into)?;
+        let signed_tx = self.signer.sign_transaction(tx).map_err(Into::into)?;
 
         // broadcast it
         self.provider.send_raw_transaction(&signed_tx).await?;
@@ -148,7 +143,10 @@ where
         tx: &mut TransactionRequest,
         block: Option<BlockNumber>,
     ) -> Result<(), ClientError> {
-        tx.from = Some(self.address());
+        // set the `from` field
+        if tx.from.is_none() {
+            tx.from = Some(self.address());
+        }
 
         // will poll and await the futures concurrently
         let (gas_price, gas, nonce) = join!(
@@ -166,12 +164,9 @@ where
         Ok(())
     }
 
-    /// Returns the client's address (or `address(0)` if no signer is set)
+    /// Returns the client's address
     pub fn address(&self) -> Address {
-        self.signer
-            .as_ref()
-            .map(|s| s.address())
-            .unwrap_or_default()
+        self.signer.address()
     }
 
     /// Returns a reference to the client's provider
@@ -180,31 +175,23 @@ where
     }
 
     /// Returns a reference to the client's signer
-    ///
-    /// # Panics
-    ///
-    /// If `self.signer` is `None`
-    pub fn signer_unchecked(&self) -> &S {
-        self.signer.as_ref().expect("no signer is configured")
+    pub fn signer(&self) -> &S {
+        &self.signer
     }
 
-    /// Sets the signer
+    /// Sets the signer and returns a mutable reference to self so that it can be used in chained
+    /// calls.
     pub fn with_signer(&mut self, signer: S) -> &mut Self {
-        self.signer = Some(signer);
+        self.signer = signer;
         self
     }
 
-    /// Sets the provider
+    /// Sets the provider and returns a mutable reference to self so that it can be used in chained
+    /// calls.
     pub fn with_provider(&mut self, provider: Provider<P>) -> &mut Self {
         self.provider = provider;
         self
     }
-
-    /// Sets the default account to be used with the `eth_sign` API calls
-    pub fn from(&mut self, address: Address) -> &mut Self {
-        self.address = address;
-        self
-    }
 }
 
 /// Calls the future if `item` is None, otherwise returns a `futures::ok`

ethers-signers/src/wallet.rs

@@ -67,7 +67,7 @@ impl Wallet {
         let address = self.address();
         Client {
             address,
-            signer: Some(self),
+            signer: self,
             provider,
         }
     }