diff --git a/tests/unit_tests/test_main_app.py b/tests/unit_tests/test_main_app.py
new file mode 100644
index 00000000..3d3a42f1
--- /dev/null
+++ b/tests/unit_tests/test_main_app.py
@@ -0,0 +1,111 @@
+import pytest
+from qtpy.QtWidgets import QWidget
+
+from bec_widgets.applications.main_app import BECMainApp
+from bec_widgets.applications.views.view import ViewBase
+
+from .client_mocks import mocked_client
+
+ANIM_TEST_DURATION = 60  # ms
+
+
+@pytest.fixture
+def viewbase(qtbot):
+    v = ViewBase(content=QWidget())
+    qtbot.addWidget(v)
+    qtbot.waitExposed(v)
+    yield v
+
+
+# Spy views for testing enter/exit hooks and veto logic
+class SpyView(ViewBase):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.enter_calls = 0
+        self.exit_calls = 0
+
+    def on_enter(self) -> None:
+        self.enter_calls += 1
+
+    def on_exit(self) -> bool:
+        self.exit_calls += 1
+        return True
+
+
+class SpyVetoView(SpyView):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.allow_exit = False
+
+    def on_exit(self) -> bool:
+        self.exit_calls += 1
+        return bool(self.allow_exit)
+
+
+@pytest.fixture
+def app_with_spies(qtbot, mocked_client):
+    app = BECMainApp(client=mocked_client, anim_duration=ANIM_TEST_DURATION, show_examples=False)
+    qtbot.addWidget(app)
+    qtbot.waitExposed(app)
+
+    app.add_section("Tests", id="tests")
+
+    v1 = SpyView(id="v1", title="V1")
+    v2 = SpyView(id="v2", title="V2")
+    vv = SpyVetoView(id="vv", title="VV")
+
+    app.add_view(icon="widgets", title="View 1", id="v1", widget=v1, mini_text="v1")
+    app.add_view(icon="widgets", title="View 2", id="v2", widget=v2, mini_text="v2")
+    app.add_view(icon="widgets", title="Veto View", id="vv", widget=vv, mini_text="vv")
+
+    # Start from dock_area (default) to avoid extra enter/exit counts on spies
+    assert app.stack.currentIndex() == app._view_index["dock_area"]
+    return app, v1, v2, vv
+
+
+def test_viewbase_initializes(viewbase):
+    assert viewbase.on_enter() is None
+    assert viewbase.on_exit() is True
+
+
+def test_on_enter_and_on_exit_are_called_on_switch(app_with_spies, qtbot):
+    app, v1, v2, _ = app_with_spies
+
+    app.set_current("v1")
+    qtbot.wait(10)
+    assert v1.enter_calls == 1
+
+    app.set_current("v2")
+    qtbot.wait(10)
+    assert v1.exit_calls == 1
+    assert v2.enter_calls == 1
+
+    app.set_current("v1")
+    qtbot.wait(10)
+    assert v2.exit_calls == 1
+    assert v1.enter_calls == 2
+
+
+def test_on_exit_veto_prevents_switch_until_allowed(app_with_spies, qtbot):
+    app, v1, v2, vv = app_with_spies
+
+    # Move to veto view first
+    app.set_current("vv")
+    qtbot.wait(10)
+    assert vv.enter_calls == 1
+
+    # Attempt to leave veto view -> should veto
+    app.set_current("v1")
+    qtbot.wait(10)
+    assert vv.exit_calls == 1
+    # Still on veto view because veto returned False
+    assert app.stack.currentIndex() == app._view_index["vv"]
+
+    # Allow exit and try again
+    vv.allow_exit = True
+    app.set_current("v1")
+    qtbot.wait(10)
+
+    # Now the switch should have happened, and v1 received on_enter
+    assert app.stack.currentIndex() == app._view_index["v1"]
+    assert v1.enter_calls >= 1