use crate::types::PrivateKey; use std::{ io::{BufRead, BufReader}, net::TcpListener, process::{Child, Command}, time::{Duration, Instant}, }; /// How long we will wait for ganache to indicate that it is ready. const GANACHE_STARTUP_TIMEOUT_MILLIS: u64 = 10_000; /// A ganache CLI instance. Will close the instance when dropped. /// /// Construct this using [`Ganache`](crate::utils::Ganache) pub struct GanacheInstance { pid: Child, private_keys: Vec, port: u16, } impl GanacheInstance { /// Returns the private keys used to instantiate this instance pub fn keys(&self) -> &[PrivateKey] { &self.private_keys } /// 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 GanacheInstance { fn drop(&mut self) { let _ = self.pid.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 /// /// ```no_run /// use ethers::utils::Ganache; /// /// let port = 8545u16; /// let url = format!("http://localhost:{}", port).to_string(); /// /// let ganache = Ganache::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 Ganache { port: Option, block_time: Option, mnemonic: Option, } impl Ganache { /// 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>(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>(mut self, mnemonic: T) -> Self { self.mnemonic = Some(mnemonic.into()); self } /// Sets the block-time which will be used when the `ganache-cli` instance is launched. pub fn block_time>(mut self, block_time: T) -> Self { self.block_time = Some(block_time.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) -> GanacheInstance { let mut cmd = Command::new("ganache-cli"); 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()); } let mut child = cmd.spawn().expect("couldnt start ganache-cli"); let stdout = child .stdout .expect("Unable to get stdout for ganache child process"); let start = Instant::now(); let mut reader = BufReader::new(stdout); let mut private_keys = Vec::new(); let mut is_private_key = false; loop { if start + Duration::from_millis(GANACHE_STARTUP_TIMEOUT_MILLIS) <= Instant::now() { panic!("Timed out waiting for ganache to start. Is ganache-cli installed?") } let mut line = String::new(); reader .read_line(&mut line) .expect("Failed to read line from ganache process"); if line.starts_with("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: PrivateKey = key_str.parse().expect("did not get private key"); private_keys.push(key); } } child.stdout = Some(reader.into_inner()); GanacheInstance { pid: child, private_keys, port, } } } /// A bit of hack to find an unused TCP port. /// /// Does not guarantee that the given port is unused after the function exists, just that it was /// unused before the function started (i.e., it does not reserve a port). pub fn unused_port() -> u16 { let listener = TcpListener::bind("127.0.0.1:0") .expect("Failed to create TCP listener to find unused port"); let local_addr = listener .local_addr() .expect("Failed to read TCP listener local_addr to find unused port"); local_addr.port() }