watchexec/lib/examples/demo.rs

use watchexec::{
	action::{Action, Outcome},
	config::{InitConfigBuilder, RuntimeConfig},
	error::ReconfigError,
	fs::Watcher,
	signal::Signal,
	Watchexec,
};

// Run with: `env RUST_LOG=debug cargo run --example print_out`
#[tokio::main]
async fn main() -> color_eyre::eyre::Result<()> {
	tracing_subscriber::fmt::init();
	color_eyre::install()?;

	let mut init = InitConfigBuilder::default();
	init.on_error(|err| async move {
		eprintln!("Watchexec Runtime Error: {}", err);
		Ok::<(), std::convert::Infallible>(())
	});

	let mut runtime = RuntimeConfig::default();
	runtime.pathset(["src"]);
	runtime.command(["date"]);

	let wx = Watchexec::new(init.build()?, runtime.clone())?;
	let w = wx.clone();

	let config = runtime.clone();
	runtime.on_action(move |action: Action| {
		let mut config = config.clone();
		let w = w.clone();
		async move {
			eprintln!("Watchexec Action: {:?}", action);

			let sigs = action
				.events
				.iter()
				.flat_map(|event| event.signals())
				.collect::<Vec<_>>();

			if sigs.iter().any(|sig| sig == &Signal::Interrupt) {
				action.outcome(Outcome::Exit);
			} else if sigs.iter().any(|sig| sig == &Signal::User1) {
				eprintln!("Switching to native for funsies");
				config.file_watcher(Watcher::Native).keep_action();
				w.reconfigure(config)?;
			} else if sigs.iter().any(|sig| sig == &Signal::User2) {
				eprintln!("Switching to polling for funsies");
				config.file_watcher(Watcher::Poll).keep_action();
				w.reconfigure(config)?;
			} else {
				action.outcome(Outcome::if_running(
					Outcome::both(Outcome::Stop, Outcome::Start),
					Outcome::Start,
				));
			}

			Ok::<(), ReconfigError>(())
		}
	});

	wx.reconfigure(runtime)?;
	wx.main().await??;

	Ok(())
}