Add watch run unit test

cli-bin/tests/watch_unit.rs

@@ -0,0 +1,35 @@
+use std::thread;
+use std::time::Duration;
+use tempfile::tempdir;
+
+use marlin_cli::cli::{watch, Format};
+use marlin_cli::cli::watch::WatchCmd;
+use libmarlin::watcher::WatcherState;
+use libmarlin::{self as marlin, db};
+use libc;
+
+#[test]
+fn watch_start_and_stop_quickly() {
+    let tmp = tempdir().unwrap();
+    let db_path = tmp.path().join("index.db");
+    std::env::set_var("MARLIN_DB_PATH", &db_path);
+
+    // create database
+    let _m = marlin::Marlin::open_default().unwrap();
+
+    let mut conn = db::open(&db_path).unwrap();
+
+    let path = tmp.path().to_path_buf();
+    let cmd = WatchCmd::Start { path: path.clone(), debounce_ms: 50 };
+
+    // send SIGINT shortly after watcher starts
+    let t = thread::spawn(|| {
+        thread::sleep(Duration::from_millis(200));
+        unsafe { libc::raise(libc::SIGINT) };
+    });
+
+    watch::run(&cmd, &mut conn, Format::Text).unwrap();
+    t.join().unwrap();
+
+    assert_eq!(watch::last_watcher_state(), Some(WatcherState::Stopped));
+}