diff --git a/src/app_event.rs b/src/app_event.rs
index ed8d987..dc2d6ad 100644
--- a/src/app_event.rs
+++ b/src/app_event.rs
@@ -768,3 +768,7 @@ impl App {
         }
     }
 }
+
+#[cfg(test)]
+#[path = "app_event_test.rs"]
+mod tests;
diff --git a/src/app_event_test.rs b/src/app_event_test.rs
new file mode 100644
index 0000000..bdf74f9
--- /dev/null
+++ b/src/app_event_test.rs
@@ -0,0 +1,59 @@
+use crate::app_state::AppState;
+use crate::config::Config;
+use crate::theme::default_theme;
+
+fn make_state() -> AppState {
+    AppState::new(Config::default(), default_theme())
+}
+
+#[test]
+fn push_search_history_ignores_empty_query() {
+    let mut s = make_state();
+    s.push_search_history(String::new());
+    assert!(s.search_history.is_empty());
+}
+
+#[test]
+fn push_search_history_appends_in_order() {
+    let mut s = make_state();
+    s.push_search_history("foo".into());
+    s.push_search_history("bar".into());
+    assert_eq!(s.search_history, vec!["foo".to_string(), "bar".to_string()]);
+}
+
+#[test]
+fn push_search_history_dedupes_moving_existing_to_end() {
+    let mut s = make_state();
+    s.push_search_history("foo".into());
+    s.push_search_history("bar".into());
+    s.push_search_history("foo".into());
+    // "foo" must not appear twice; the re-search moves it to the most-recent slot.
+    assert_eq!(s.search_history, vec!["bar".to_string(), "foo".to_string()]);
+}
+
+#[test]
+fn push_search_history_caps_at_50_entries_dropping_oldest() {
+    let mut s = make_state();
+    for i in 0..60 {
+        s.push_search_history(format!("q{i}"));
+    }
+    assert_eq!(
+        s.search_history.len(),
+        50,
+        "history is capped at 50 entries"
+    );
+    // The 10 oldest (q0..q9) were dropped; q10 is now the oldest, q59 the newest.
+    assert_eq!(s.search_history.first().unwrap(), "q10");
+    assert_eq!(s.search_history.last().unwrap(), "q59");
+}
+
+#[test]
+fn push_search_history_clears_pending_before_buffer() {
+    let mut s = make_state();
+    s.search_before_history = "draft".into();
+    s.push_search_history("committed".into());
+    assert!(
+        s.search_before_history.is_empty(),
+        "committing a search must clear the saved in-progress query"
+    );
+}
diff --git a/src/input_ops.rs b/src/input_ops.rs
index 878bf57..6bd8f67 100644
--- a/src/input_ops.rs
+++ b/src/input_ops.rs
@@ -244,3 +244,7 @@ impl App {
         false
     }
 }
+
+#[cfg(test)]
+#[path = "input_ops_test.rs"]
+mod tests;
diff --git a/src/input_ops_test.rs b/src/input_ops_test.rs
new file mode 100644
index 0000000..4ef5a77
--- /dev/null
+++ b/src/input_ops_test.rs
@@ -0,0 +1,46 @@
+use super::bracketed_paste_encode;
+
+const PASTE_START: &[u8] = b"\x1b[200~";
+const PASTE_END: &[u8] = b"\x1b[201~";
+
+#[test]
+fn bracketed_paste_wraps_text_in_markers() {
+    let out = bracketed_paste_encode("hi", true);
+    let mut expected = Vec::new();
+    expected.extend_from_slice(PASTE_START);
+    expected.extend_from_slice(b"hi");
+    expected.extend_from_slice(PASTE_END);
+    assert_eq!(out, expected);
+}
+
+#[test]
+fn non_bracketed_paste_passes_text_through_unchanged() {
+    let out = bracketed_paste_encode("hi", false);
+    assert_eq!(out, b"hi");
+}
+
+#[test]
+fn bracketed_paste_empty_text_still_emits_markers() {
+    // An empty paste in bracketed mode is start+end with nothing between, so a
+    // program in bracketed-paste mode still sees a (zero-length) paste event.
+    let out = bracketed_paste_encode("", true);
+    let mut expected = Vec::new();
+    expected.extend_from_slice(PASTE_START);
+    expected.extend_from_slice(PASTE_END);
+    assert_eq!(out, expected);
+}
+
+#[test]
+fn non_bracketed_empty_text_is_empty() {
+    assert!(bracketed_paste_encode("", false).is_empty());
+}
+
+#[test]
+fn bracketed_paste_preserves_inner_bytes_including_newlines() {
+    let out = bracketed_paste_encode("a\nb", true);
+    // The payload between the markers must be byte-for-byte the original text.
+    assert_eq!(
+        &out[PASTE_START.len()..out.len() - PASTE_END.len()],
+        b"a\nb"
+    );
+}
diff --git a/src/restore.rs b/src/restore.rs
index c36b6af..acc25a0 100644
--- a/src/restore.rs
+++ b/src/restore.rs
@@ -176,3 +176,7 @@ impl App {
         }
     }
 }
+
+#[cfg(test)]
+#[path = "restore_test.rs"]
+mod tests;
diff --git a/src/restore_test.rs b/src/restore_test.rs
new file mode 100644
index 0000000..2801939
--- /dev/null
+++ b/src/restore_test.rs
@@ -0,0 +1,89 @@
+use crate::config::Config;
+use crate::session::{SavedNode, SavedSession, SavedTab};
+
+use super::App;
+
+/// Builds an EventLoop that works from any thread (needed for tests).
+/// Returns `None` when no display is available (headless CI) so callers skip.
+/// Mirrors the helper in `pane_ops_test.rs` / `main_test.rs`.
+fn make_event_loop() -> Option<winit::event_loop::EventLoop<()>> {
+    #[cfg(target_os = "linux")]
+    {
+        use winit::event_loop::EventLoopBuilder;
+        use winit::platform::x11::EventLoopBuilderExtX11;
+        EventLoopBuilder::new().with_any_thread(true).build().ok()
+    }
+    #[cfg(not(target_os = "linux"))]
+    {
+        winit::event_loop::EventLoop::new().ok()
+    }
+}
+
+/// Headless App with no window; `None` if no display is available.
+fn make_app() -> Option<App> {
+    let el = make_event_loop()?;
+    let proxy = el.create_proxy();
+    std::mem::forget(el);
+    Some(App::new(Config::default(), proxy, None))
+}
+
+fn one_pane_tab(cwd: std::path::PathBuf) -> SavedTab {
+    SavedTab {
+        name: Some("t".into()),
+        active_pane: 0,
+        pane_cwds: vec![cwd],
+        layout: SavedNode::Leaf { slot: 0 },
+    }
+}
+
+#[test]
+fn restore_session_falls_back_to_home_for_missing_cwd() {
+    let Some(mut app) = make_app() else {
+        return; // no display — skip
+    };
+    let missing = std::path::PathBuf::from("/nonexistent/path/should/not/exist");
+    let saved = SavedSession {
+        active_tab: 0,
+        tabs: vec![one_pane_tab(missing)],
+        theme: None,
+    };
+    // A non-existent CWD must not abort the restore; the pane spawns in $HOME.
+    let ok = app.restore_session(saved, 800, 600);
+    assert!(ok, "restore should succeed despite the missing CWD");
+    assert_eq!(app.state.tabs.len(), 1, "the saved tab was restored");
+    assert_eq!(
+        app.state.tabs[0].panes.len(),
+        1,
+        "the pane spawned via the $HOME fallback"
+    );
+}
+
+#[test]
+fn restore_session_handles_empty_cwd_as_home() {
+    let Some(mut app) = make_app() else {
+        return; // no display — skip
+    };
+    // An empty CWD string is the documented "fall back to $HOME" sentinel.
+    let saved = SavedSession {
+        active_tab: 0,
+        tabs: vec![one_pane_tab(std::path::PathBuf::new())],
+        theme: None,
+    };
+    assert!(app.restore_session(saved, 800, 600));
+    assert_eq!(app.state.tabs[0].panes.len(), 1);
+}
+
+#[test]
+fn restore_session_empty_tabs_is_noop() {
+    let Some(mut app) = make_app() else {
+        return; // no display — skip
+    };
+    let saved = SavedSession {
+        active_tab: 0,
+        tabs: vec![],
+        theme: None,
+    };
+    // Nothing to restore: returns false and leaves the app with no tabs.
+    assert!(!app.restore_session(saved, 800, 600));
+    assert!(app.state.tabs.is_empty());
+}
diff --git a/src/winit_handler_test.rs b/src/winit_handler_test.rs
new file mode 100644
index 0000000..5787add
--- /dev/null
+++ b/src/winit_handler_test.rs
@@ -0,0 +1,68 @@
+use std::collections::HashMap;
+use std::time::{Duration, Instant};
+
+use super::next_bell_wakeup;
+use crate::app_state::TabState;
+use crate::ui::layout::Layout;
+
+/// Builds a bare tab whose only meaningful field for these tests is
+/// `bell_flash_until`. No panes, no PTYs — `next_bell_wakeup` only reads the
+/// bell expiry.
+fn tab_with_bell(bell_until: Option<Instant>) -> TabState {
+    TabState {
+        panes: HashMap::new(),
+        layout: Layout::new(0, 800, 600),
+        active: 0,
+        name: None,
+        zoomed: false,
+        has_activity: false,
+        bell_flash_start: None,
+        bell_flash_until: bell_until,
+        bell_cooldown_until: None,
+        passthrough: false,
+    }
+}
+
+#[test]
+fn next_bell_wakeup_empty_tabs_returns_default() {
+    let default = Instant::now() + Duration::from_secs(10);
+    assert_eq!(next_bell_wakeup(&[], default), default);
+}
+
+#[test]
+fn next_bell_wakeup_ignores_tabs_without_bell() {
+    let default = Instant::now() + Duration::from_secs(10);
+    let tabs = [tab_with_bell(None), tab_with_bell(None)];
+    assert_eq!(next_bell_wakeup(&tabs, default), default);
+}
+
+#[test]
+fn next_bell_wakeup_ignores_expired_bell() {
+    let default = Instant::now() + Duration::from_secs(10);
+    // A bell that already expired must not pull the wakeup into the past.
+    let past = Instant::now() - Duration::from_millis(1);
+    let tabs = [tab_with_bell(Some(past))];
+    assert_eq!(next_bell_wakeup(&tabs, default), default);
+}
+
+#[test]
+fn next_bell_wakeup_picks_earliest_future_bell() {
+    let default = Instant::now() + Duration::from_secs(10);
+    let soon = Instant::now() + Duration::from_millis(200);
+    let later = Instant::now() + Duration::from_secs(5);
+    let tabs = [tab_with_bell(Some(later)), tab_with_bell(Some(soon))];
+    assert_eq!(
+        next_bell_wakeup(&tabs, default),
+        soon,
+        "must wake at the soonest pending bell, earlier than the default"
+    );
+}
+
+#[test]
+fn next_bell_wakeup_future_bell_after_default_is_ignored() {
+    // A bell later than the default deadline must not delay the wakeup.
+    let default = Instant::now() + Duration::from_millis(100);
+    let far = Instant::now() + Duration::from_secs(30);
+    let tabs = [tab_with_bell(Some(far))];
+    assert_eq!(next_bell_wakeup(&tabs, default), default);
+}