feat: add anvil bindings (#1164)

ethers-core/src/utils/anvil.rs

@@ -0,0 +1,217 @@
+use crate::{
+    types::Address,
+    utils::{secret_key_to_address, unused_port},
+};
+use k256::{ecdsa::SigningKey, SecretKey as K256SecretKey};
+use std::{
+    io::{BufRead, BufReader},
+    process::{Child, Command},
+    time::{Duration, Instant},
+};
+
+/// How long we will wait for anvil to indicate that it is ready.
+const ANVIL_STARTUP_TIMEOUT_MILLIS: u64 = 5_000;
+
+/// An anvil CLI instance. Will close the instance when dropped.
+///
+/// Construct this using [`Anvil`](crate::utils::Anvil)
+pub struct AnvilInstance {
+    pid: Child,
+    private_keys: Vec<K256SecretKey>,
+    addresses: Vec<Address>,
+    port: u16,
+}
+
+impl AnvilInstance {
+    /// Returns the private keys used to instantiate this instance
+    pub fn keys(&self) -> &[K256SecretKey] {
+        &self.private_keys
+    }
+
+    /// Returns the addresses used to instantiate this instance
+    pub fn addresses(&self) -> &[Address] {
+        &self.addresses
+    }
+
+    /// Returns the port of this instance
+    pub fn port(&self) -> u16 {
+        self.port
+    }
+
+    /// Returns the HTTP endpoint of this instance
+    pub fn endpoint(&self) -> String {
+        format!("http://localhost:{}", self.port)
+    }
+
+    /// Returns the Websocket endpoint of this instance
+    pub fn ws_endpoint(&self) -> String {
+        format!("ws://localhost:{}", self.port)
+    }
+}
+
+impl Drop for AnvilInstance {
+    fn drop(&mut self) {
+        let _ = self.pid.kill().expect("could not kill anvil");
+    }
+}
+
+/// Builder for launching `anvil`.
+///
+/// # Panics
+///
+/// If `spawn` is called without `anvil` being available in the user's $PATH
+///
+/// # Example
+///
+/// ```no_run
+/// use ethers_core::utils::Anvil;
+///
+/// let port = 8545u16;
+/// let url = format!("http://localhost:{}", port).to_string();
+///
+/// let anvil = Anvil::new()
+///     .port(port)
+///     .mnemonic("abstract vacuum mammal awkward pudding scene penalty purchase dinner depart evoke puzzle")
+///     .spawn();
+///
+/// drop(anvil); // this will kill the instance
+/// ```
+#[derive(Debug, Clone, Default)]
+pub struct Anvil {
+    port: Option<u16>,
+    block_time: Option<u64>,
+    mnemonic: Option<String>,
+    fork: Option<String>,
+    args: Vec<String>,
+}
+
+impl Anvil {
+    /// Creates an empty Anvil 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 `anvil` instance is launched.
+    #[must_use]
+    pub fn port<T: Into<u16>>(mut self, port: T) -> Self {
+        self.port = Some(port.into());
+        self
+    }
+
+    /// Sets the mnemonic which will be used when the `anvil` instance is launched.
+    #[must_use]
+    pub fn mnemonic<T: Into<String>>(mut self, mnemonic: T) -> Self {
+        self.mnemonic = Some(mnemonic.into());
+        self
+    }
+
+    /// Sets the block-time which will be used when the `anvil` instance is launched.
+    #[must_use]
+    pub fn block_time<T: Into<u64>>(mut self, block_time: T) -> Self {
+        self.block_time = Some(block_time.into());
+        self
+    }
+
+    /// Sets the `fork` argument to fork from another currently running Ethereum client
+    /// at a given block. Input should be the HTTP location and port of the other client,
+    /// e.g. `http://localhost:8545`. You can optionally specify the block to fork from
+    /// using an @ sign: `http://localhost:8545@1599200`
+    #[must_use]
+    pub fn fork<T: Into<String>>(mut self, fork: T) -> Self {
+        self.fork = Some(fork.into());
+        self
+    }
+
+    /// Adds an argument to pass to the `anvil`.
+    #[must_use]
+    pub fn arg<T: Into<String>>(mut self, arg: T) -> Self {
+        self.args.push(arg.into());
+        self
+    }
+
+    /// Adds multiple arguments to pass to the `anvil`.
+    #[must_use]
+    pub fn args<I, S>(mut self, args: I) -> Self
+    where
+        I: IntoIterator<Item = S>,
+        S: Into<String>,
+    {
+        for arg in args {
+            self = self.arg(arg);
+        }
+        self
+    }
+
+    /// Consumes the builder and spawns `anvil` with stdout redirected
+    /// to /dev/null.
+    pub fn spawn(self) -> AnvilInstance {
+        let mut cmd = Command::new("anvil");
+        cmd.stdout(std::process::Stdio::piped());
+        let port = if let Some(port) = self.port { port } else { unused_port() };
+        cmd.arg("-p").arg(port.to_string());
+
+        if let Some(mnemonic) = self.mnemonic {
+            cmd.arg("-m").arg(mnemonic);
+        }
+
+        if let Some(block_time) = self.block_time {
+            cmd.arg("-b").arg(block_time.to_string());
+        }
+
+        if let Some(fork) = self.fork {
+            cmd.arg("-f").arg(fork);
+        }
+
+        cmd.args(self.args);
+
+        let mut child = cmd.spawn().expect("couldnt start anvil");
+
+        let stdout = child.stdout.expect("Unable to get stdout for anvil child process");
+
+        let start = Instant::now();
+        let mut reader = BufReader::new(stdout);
+
+        let mut private_keys = Vec::new();
+        let mut addresses = Vec::new();
+        let mut is_private_key = false;
+        loop {
+            if start + Duration::from_millis(ANVIL_STARTUP_TIMEOUT_MILLIS) <= Instant::now() {
+                panic!("Timed out waiting for anvil to start. Is anvil installed?")
+            }
+
+            let mut line = String::new();
+            reader.read_line(&mut line).expect("Failed to read line from anvil process");
+            if line.contains("Listening on") {
+                break
+            }
+
+            if line.starts_with("Private Keys") {
+                is_private_key = true;
+            }
+
+            if is_private_key && line.starts_with('(') {
+                let key_str = &line[6..line.len() - 1];
+                let key_hex = hex::decode(key_str).expect("could not parse as hex");
+                let key = K256SecretKey::from_be_bytes(&key_hex).expect("did not get private key");
+                addresses.push(secret_key_to_address(&SigningKey::from(&key)));
+                private_keys.push(key);
+            }
+        }
+
+        child.stdout = Some(reader.into_inner());
+
+        AnvilInstance { pid: child, private_keys, addresses, port }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[ignore]
+    fn can_launch_anvil() {
+        let _ = Anvil::new().spawn();
+    }
+}

ethers-core/src/utils/mod.rs

@@ -10,6 +10,12 @@ mod geth;
 #[cfg(not(target_arch = "wasm32"))]
 pub use geth::{Geth, GethInstance};
 
+/// Utilities for launching an anvil instance
+#[cfg(not(target_arch = "wasm32"))]
+mod anvil;
+#[cfg(not(target_arch = "wasm32"))]
+pub use anvil::{Anvil, AnvilInstance};
+
 /// Moonbeam utils
 pub mod moonbeam;