feat: Adds support for launching ganache-cli

crates/ethers-contract/src/event.rs

@@ -31,7 +31,7 @@ impl<'a, 'b, P, N, D: Detokenize> Event<'a, 'b, P, N, D> {
     }
 
     pub fn topic0<T: Into<ValueOrArray<H256>>>(mut self, topic: T) -> Self {
-        self.filter.topics[0] = topic.into();
+        self.filter.topics[0] = Some(topic.into());
         self
     }
 }

crates/ethers-utils/src/ganache.rs

@@ -0,0 +1,79 @@
+use std::process::{Child, Command};
+
+/// A ganache CLI instance. Will close the instance when dropped.
+pub struct Ganache(Child);
+
+impl Drop for Ganache {
+    fn drop(&mut self) {
+        self.0.kill().expect("could not kill ganache");
+    }
+}
+
+/// Builder for launching `ganache-cli`.
+///
+/// # Panics
+///
+/// If `spawn` is called without `ganache-cli` being available in the user's $PATH
+///
+/// # Example
+///
+/// ```rust,ignore
+/// use ethers_utils::ganache::GanacheBuilder;
+/// let port = 8545u64;
+/// let url = format!("http://localhost:{}", port).to_string();
+///
+/// let ganache = GanacheBuilder::new()
+///     .port(port)
+///     .mnemonic("abstract vacuum mammal awkward pudding scene penalty purchase dinner depart evoke puzzle")
+///     .spawn();
+///
+/// drop(ganache); // this will kill the instance
+/// ```
+#[derive(Clone, Default)]
+pub struct GanacheBuilder {
+    port: Option<u64>,
+    mnemonic: Option<String>,
+}
+
+impl GanacheBuilder {
+    /// Creates an empty Ganache builder.
+    /// The default port is 8545. The mnemonic is chosen randomly.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Sets the port which will be used when the `ganache-cli` instance is launched.
+    pub fn port<T: Into<u64>>(mut self, port: T) -> Self {
+        self.port = Some(port.into());
+        self
+    }
+
+    /// Sets the mnemonic which will be used when the `ganache-cli` instance is launched.
+    pub fn mnemonic<T: Into<String>>(mut self, mnemonic: T) -> Self {
+        self.mnemonic = Some(mnemonic.into());
+        self
+    }
+
+    /// Consumes the builder and spawns `ganache-cli` with stdout redirected
+    /// to /dev/null. This takes ~2 seconds to execute as it blocks while
+    /// waiting for `ganache-cli` to launch.
+    pub fn spawn(self) -> Ganache {
+        let mut cmd = Command::new("ganache-cli");
+        cmd.stdout(std::process::Stdio::null());
+        if let Some(port) = self.port {
+            cmd.arg("-p").arg(port.to_string());
+        }
+
+        if let Some(mnemonic) = self.mnemonic {
+            cmd.arg("-m").arg(mnemonic);
+        }
+
+        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);
+        Ganache(ganache_pid)
+    }
+}

crates/ethers-utils/src/lib.rs

@@ -2,6 +2,9 @@
 use ethereum_types::H256;
 use tiny_keccak::{Hasher, Keccak};
 
+/// Utilities for launching a ganache-cli testnet instance
+pub mod ganache;
+
 const PREFIX: &str = "\x19Ethereum Signed Message:\n";
 
 /// Hash a message according to EIP-191.

crates/ethers/examples/get_logs.rs

@@ -13,7 +13,7 @@ async fn main() -> Result<()> {
     let filter = Filter::new()
         .address_str("f817796F60D268A36a57b8D2dF1B97B14C0D0E1d")?
         .event("ValueChanged(address,string,string)") // event name
-        .topic("9729a6fbefefc8f6005933898b13dc45c3a2c8b7".parse::<Address>()?); // indexed param
+        .topic0("9729a6fbefefc8f6005933898b13dc45c3a2c8b7".parse::<Address>()?); // indexed param
 
     let logs = provider.get_logs(&filter).await?;
     println!("Got logs: {}", serde_json::to_string(&logs).unwrap());

crates/ethers/examples/local_signer.rs

@@ -1,16 +1,27 @@
 use anyhow::Result;
-use ethers::{providers::HttpProvider, signers::MainnetWallet, types::TransactionRequest};
+use ethers::{
+    providers::HttpProvider, signers::MainnetWallet, types::TransactionRequest,
+    utils::ganache::GanacheBuilder,
+};
 use std::convert::TryFrom;
 
 #[tokio::main]
 async fn main() -> Result<()> {
-    // connect to the network
-    let provider = HttpProvider::try_from("http://localhost:8545")?;
+    let port = 8545u64;
+    let url = format!("http://localhost:{}", port).to_string();
+    let _ganache = GanacheBuilder::new()
+        .port(port)
+        .mnemonic("abstract vacuum mammal awkward pudding scene penalty purchase dinner depart evoke puzzle")
+        .spawn();
+    // this private key belongs to the above mnemonic
+    let wallet: MainnetWallet =
+        "380eb0f3d505f087e438eca80bc4df9a7faa24f868e69fc0440261a0fc0567dc".parse()?;
 
-    // create a wallet and connect it to the provider
-    let client = "dcf2cbdd171a21c480aa7f53d77f31bb102282b3ff099c78e3118b37348c72f7"
-        .parse::<MainnetWallet>()?
-        .connect(&provider);
+    // connect to the network
+    let provider = HttpProvider::try_from(url.as_str())?;
+
+    // connect the wallet to the provider
+    let client = wallet.connect(&provider);
 
     // craft the transaction
     let tx = TransactionRequest::new()
@@ -25,8 +36,8 @@ async fn main() -> Result<()> {
 
     let receipt = client.get_transaction_receipt(tx.hash).await?;
 
-    println!("{}", serde_json::to_string(&tx)?);
-    println!("{}", serde_json::to_string(&receipt)?);
+    println!("Send tx: {}", serde_json::to_string(&tx)?);
+    println!("Tx receipt: {}", serde_json::to_string(&receipt)?);
 
     Ok(())
 }

crates/ethers/examples/transfer_eth.rs

@@ -2,13 +2,18 @@ use anyhow::Result;
 use ethers::{
     providers::{networks::Any, HttpProvider},
     types::{BlockNumber, TransactionRequest},
+    utils::ganache::GanacheBuilder,
 };
 use std::convert::TryFrom;
 
 #[tokio::main]
 async fn main() -> Result<()> {
+    let port = 8546u64;
+    let url = format!("http://localhost:{}", port).to_string();
+    let _ganache = GanacheBuilder::new().port(port).spawn();
+
     // connect to the network
-    let provider = HttpProvider::<Any>::try_from("http://localhost:8545")?;
+    let provider = HttpProvider::<Any>::try_from(url.as_str())?;
     let accounts = provider.get_accounts().await?;
     let from = accounts[0];