feat(bus): tines-bus transport and daemon over a host IPC bus

tines-bus/tests/common/mod.rs

@@ -0,0 +1,34 @@
+//! Shared helpers for the tines-bus integration tests.
+#![allow(dead_code)]
+
+use std::path::{Path, PathBuf};
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+static COUNTER: AtomicUsize = AtomicUsize::new(0);
+
+/// A fresh, unique scratch directory under the system temp dir.
+pub fn unique_dir(tag: &str) -> PathBuf {
+    let n = COUNTER.fetch_add(1, Ordering::Relaxed);
+    let dir = std::env::temp_dir().join(format!("tines-bus-{tag}-{}-{n}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    dir
+}
+
+/// Spawn the bus daemon on a thread and return its socket path once bound.
+pub fn spawn_daemon(dir: &Path) -> PathBuf {
+    let sock = dir.join("bus.sock");
+    let s = sock.clone();
+    std::thread::spawn(move || {
+        if let Err(e) = tines_bus::daemon::serve(&s) {
+            panic!("daemon failed: {e}");
+        }
+    });
+    // Wait for the daemon to bind, so the first connect cannot race it.
+    for _ in 0..400 {
+        if sock.exists() {
+            return sock;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    }
+    panic!("daemon did not bind in time");
+}