Add functional test for refreshing /generate page

Add a functional test to verify the behavior when refreshing the
/generate page when multiple instance of /generate are open
simultaneously.

securedrop/tests/functional/source_navigation_steps.py

@@ -40,6 +40,9 @@ def _source_clicks_submit_documents_on_homepage(self):
         # a diceware codename they can use for subsequent logins
         assert self._is_on_generate_page()
 
+    def _source_regenerates_codename(self):
+        self.safe_click_by_id("regenerate-submit")
+
     def _source_chooses_to_submit_documents(self):
         self._source_clicks_submit_documents_on_homepage()
 
@@ -231,3 +234,10 @@ def _source_sees_already_logged_in_in_other_tab_message(self):
         if not hasattr(self, "accepted_languages"):
             expected_text = "You are already logged in."
             assert expected_text in notification.text
+
+    def _source_sees_redirect_already_logged_in_message(self):
+        notification = self.driver.find_element_by_css_selector(".notification")
+
+        if not hasattr(self, "accepted_languages"):
+            expected_text = "You were redirected because you are already logged in."
+            assert expected_text in notification.text

securedrop/tests/functional/test_source.py

@@ -84,3 +84,51 @@ def test_duplicate_generate_pages(self):
         # We expect the codename to be the one from Tab A
         assert codename_lookup_b == codename_a
         self._source_submits_a_message()
+
+    def test_duplicate_generate_pages_with_refresh(self):
+        # Test generation of multiple codenames in different browser tabs, including behavior
+        # of refreshing the codemae in each tab. Ref. issue 4458.
+
+        # Generate a codename in Tab A
+        assert len(self.driver.window_handles) == 1
+        tab_a = self.driver.current_window_handle
+        self._source_visits_source_homepage()
+        self._source_chooses_to_submit_documents()
+        codename_a1 = self.get_codename_generate()
+        # Regenerate codename in Tab A
+        self._source_regenerates_codename()
+        codename_a2 = self.get_codename_generate()
+        assert codename_a1 != codename_a2
+
+        # Generate a different codename in Tab B
+        self.driver.execute_script("window.open()")
+        tab_b = self.driver.window_handles[1]
+        self.driver.switch_to.window(tab_b)
+        assert self.driver.current_window_handle == tab_b
+        self._source_visits_source_homepage()
+        self._source_chooses_to_submit_documents()
+        codename_b = self.get_codename_generate()
+        assert codename_b != codename_a1 != codename_a2
+
+        # Proceed to submit documents in Tab A
+        self.driver.switch_to.window(tab_a)
+        assert self.driver.current_window_handle == tab_a
+        self._source_continues_to_submit_page()
+        assert self._is_on_lookup_page()
+        self._source_shows_codename(verify_source_name=False)
+        codename_lookup_a = self.get_codename_lookup()
+        assert codename_lookup_a == codename_a2
+        self._source_submits_a_message()
+
+        # Regenerate codename in Tab B
+        self.driver.switch_to.window(tab_b)
+        assert self.driver.current_window_handle == tab_b
+        self._source_regenerates_codename()
+        # We expect the source to be directed to /lookup with a flash message
+        assert self._is_on_lookup_page()
+        self._source_sees_redirect_already_logged_in_message()
+        # Check codename
+        self._source_shows_codename(verify_source_name=False)
+        codename_lookup_b = self.get_codename_lookup()
+        assert codename_lookup_b == codename_a2
+        self._source_submits_a_message()