Added test for registering tabs with same name

django/website/tabbed_page/tests/registration_tests.py

@@ -29,3 +29,12 @@ def test_tab_is_registered(tab):
 def test_exception_when_tab_not_registered(tab):
     with pytest.raises(MissingTabError):
         get_tab('test-tab')
+
+
+def test_registering_twice_overrides_existing_tab(tab):
+    register_tab('test-tab', tab)
+
+    tab2 = TestTab()
+    register_tab('test-tab', tab2)
+
+    assert get_tab('test-tab') == tab2