1 files changed, 96 insertions, 0 deletions
diff --git a/pocketbook/tests/test_app_toggle.py b/pocketbook/tests/test_app_toggle.py
new file mode 100644
index 0000000..cb5ab89
--- /dev/null
+++ b/pocketbook/tests/test_app_toggle.py
@@ -0,0 +1,96 @@
+from pocketbook.app import ToggleStateMachine, EscapeStateMachine, navigate
+
+
+class TestToggleStateMachine:
+    def test_initial_state_visible(self):
+        sm = ToggleStateMachine(start_hidden=False)
+        assert sm.visible is True
+
+    def test_initial_state_hidden(self):
+        sm = ToggleStateMachine(start_hidden=True)
+        assert sm.visible is False
+
+    def test_toggle_alternates(self):
+        sm = ToggleStateMachine(start_hidden=False)
+        assert sm.visible is True
+        sm.toggle()
+        assert sm.visible is False
+        sm.toggle()
+        assert sm.visible is True
+
+    def test_toggle_from_hidden(self):
+        sm = ToggleStateMachine(start_hidden=True)
+        assert sm.visible is False
+        sm.toggle()
+        assert sm.visible is True
+        sm.toggle()
+        assert sm.visible is False
+
+
+class TestEscapeStateMachine:
+    def test_escape_while_editing_returns_exit_edit(self):
+        esc = EscapeStateMachine()
+        toggle = ToggleStateMachine(start_hidden=False)
+        action = esc.escape(is_editing=True, toggle=toggle)
+        assert action == "exit_edit"
+        # Toggle state should not change
+        assert toggle.visible is True
+
+    def test_escape_while_browsing_returns_hide(self):
+        esc = EscapeStateMachine()
+        toggle = ToggleStateMachine(start_hidden=False)
+        action = esc.escape(is_editing=False, toggle=toggle)
+        assert action == "hide"
+        assert toggle.visible is False
+
+    def test_escape_edit_then_browse_hides(self):
+        """Simulates: editing → Escape (exit edit) → Escape (hide)."""
+        esc = EscapeStateMachine()
+        toggle = ToggleStateMachine(start_hidden=False)
+
+        # First escape: exit edit mode
+        action1 = esc.escape(is_editing=True, toggle=toggle)
+        assert action1 == "exit_edit"
+        assert toggle.visible is True
+
+        # Second escape: now in browse mode, hide panel
+        action2 = esc.escape(is_editing=False, toggle=toggle)
+        assert action2 == "hide"
+        assert toggle.visible is False
+
+    def test_escape_hide_does_not_change_when_already_hidden(self):
+        esc = EscapeStateMachine()
+        toggle = ToggleStateMachine(start_hidden=True)
+        assert toggle.visible is False
+        action = esc.escape(is_editing=False, toggle=toggle)
+        assert action == "hide"
+        # Toggled again — now visible (edge case if called when hidden)
+        assert toggle.visible is True
+
+
+class TestNavigate:
+    def test_no_notes(self):
+        assert navigate(None, 0, 1) is None
+        assert navigate(None, 0, -1) is None
+
+    def test_no_focus_next_goes_to_first(self):
+        assert navigate(None, 3, 1) == 0
+
+    def test_no_focus_prev_goes_to_last(self):
+        assert navigate(None, 3, -1) == 2
+
+    def test_next_from_middle(self):
+        assert navigate(1, 3, 1) == 2
+
+    def test_prev_from_middle(self):
+        assert navigate(1, 3, -1) == 0
+
+    def test_next_clamps_at_end(self):
+        assert navigate(2, 3, 1) == 2
+
+    def test_prev_clamps_at_start(self):
+        assert navigate(0, 3, -1) == 0
+
+    def test_single_note(self):
+        assert navigate(0, 1, 1) == 0
+        assert navigate(0, 1, -1) == 0