diff --git a/qe.ipynb b/qe.ipynb
index 19accf105..32e3604e1 100644
--- a/qe.ipynb
+++ b/qe.ipynb
@@ -20,10 +20,11 @@
    "outputs": [],
    "source": [
     "import ipywidgets as ipw\n",
-    "from aiidalab_qe.app import static\n",
     "from importlib_resources import files\n",
     "from IPython.display import display\n",
     "\n",
+    "from aiidalab_qe.app import static\n",
+    "\n",
     "# load CSS stylesheets\n",
     "for stylesheet in [\"style\", \"custom\"]:\n",
     "    css = files(static).joinpath(f\"{stylesheet}.css\")\n",
diff --git a/tests/test_infobox.py b/tests/test_infobox.py
new file mode 100644
index 000000000..40d9f66a7
--- /dev/null
+++ b/tests/test_infobox.py
@@ -0,0 +1,15 @@
+from aiidalab_qe.app.infobox import InfoBox
+
+
+def test_infobox_classes():
+    """Test `InfoBox` classes."""
+    infobox = InfoBox()
+    assert "info-box" in infobox._dom_classes
+    infobox = InfoBox(**{"custom-css": "custom-info-box"})
+    assert all(
+        css_class in infobox._dom_classes
+        for css_class in (
+            "info-box",
+            "custom-info-box",
+        )
+    )
diff --git a/tests/test_wrapper.py b/tests/test_wrapper.py
new file mode 100644
index 000000000..609fa40d8
--- /dev/null
+++ b/tests/test_wrapper.py
@@ -0,0 +1,64 @@
+from aiidalab_qe.app.wrapper import AppWrapperContoller, AppWrapperModel, AppWrapperView
+
+
+class TestWrapper:
+    def test_enable_toggles(self):
+        """Test enable_toggles method."""
+        self._instansiate_mvc_components()
+        assert self.view.guide_toggle.disabled is True
+        assert self.view.about_toggle.disabled is True
+        self.controller.enable_toggles()
+        assert self.view.guide_toggle.disabled is False
+        assert self.view.about_toggle.disabled is False
+
+    def test_guide_toggle(self):
+        """Test guide_toggle method."""
+        self._instansiate_mvc_components()
+        self.controller.enable_toggles()
+        self.controller._on_guide_toggle({"new": True})
+        self._assert_guide_is_on()
+        self.controller._on_guide_toggle({"new": False})
+        self._assert_no_guide_info()
+
+    def test_about_toggle(self):
+        """Test about_toggle method."""
+        self._instansiate_mvc_components()
+        self.controller.enable_toggles()
+        self.controller._on_about_toggle({"new": True})
+        self._assert_about_is_on()
+        self.controller._on_about_toggle({"new": False})
+        self._assert_no_guide_info()
+
+    def test_toggle_switch(self):
+        """Test toggle_switch method."""
+        self._instansiate_mvc_components()
+        self.controller.enable_toggles()
+        self._assert_no_guide_info()
+        self.controller._on_guide_toggle({"new": True})
+        self._assert_guide_is_on()
+        self.controller._on_about_toggle({"new": True})
+        self._assert_about_is_on()
+        self.controller._on_guide_toggle({"new": True})
+        self._assert_guide_is_on()
+        self.controller._on_guide_toggle({"new": False})
+        self._assert_no_guide_info()
+
+    def _assert_guide_is_on(self):
+        """Assert guide is on."""
+        assert len(self.view.info_container.children) == 1
+        assert self.view.guide in self.view.info_container.children
+
+    def _assert_about_is_on(self):
+        """Assert about is on."""
+        assert len(self.view.info_container.children) == 1
+        assert self.view.about in self.view.info_container.children
+
+    def _assert_no_guide_info(self):
+        """Assert no info is shown."""
+        assert len(self.view.info_container.children) == 0
+
+    def _instansiate_mvc_components(self):
+        """Instansiate `AppWrapper` MVC components."""
+        self.model = AppWrapperModel()
+        self.view = AppWrapperView()
+        self.controller = AppWrapperContoller(self.model, self.view)