Refs #34043 -- Added context managers to SeleniumTestCase for changing window size.

django/test/selenium.py

@@ -98,6 +98,20 @@ class SeleniumTestCaseBase(type(LiveServerTestCase)):
         return self.import_webdriver(self.browser)(options=options)
 
 
+class ChangeWindowSize:
+    def __init__(self, width, height, selenium):
+        self.selenium = selenium
+        self.new_size = (width, height)
+
+    def __enter__(self):
+        self.old_size = self.selenium.get_window_size()
+        self.selenium.set_window_size(*self.new_size)
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.selenium.set_window_size(self.old_size["width"], self.old_size["height"])
+
+
 @tag("selenium")
 class SeleniumTestCase(LiveServerTestCase, metaclass=SeleniumTestCaseBase):
     implicit_wait = 10
@@ -118,6 +132,21 @@ class SeleniumTestCase(LiveServerTestCase, metaclass=SeleniumTestCaseBase):
         super().setUpClass()
         cls.addClassCleanup(cls._quit_selenium)
 
+    @contextmanager
+    def desktop_size(self):
+        with ChangeWindowSize(1280, 720, self.selenium):
+            yield
+
+    @contextmanager
+    def small_screen_size(self):
+        with ChangeWindowSize(1024, 768, self.selenium):
+            yield
+
+    @contextmanager
+    def mobile_size(self):
+        with ChangeWindowSize(360, 800, self.selenium):
+            yield
+
     @classmethod
     def _quit_selenium(cls):
         # quit() the WebDriver before attempting to terminate and join the

tests/admin_views/tests.py

@@ -6489,14 +6489,10 @@ class SeleniumTests(AdminSeleniumTestCase):
         )
         self.selenium.get(self.live_server_url + reverse("admin:admin_views_story_add"))
         field_title = self.selenium.find_element(By.CLASS_NAME, "field-title")
-        current_size = self.selenium.get_window_size()
+        with self.small_screen_size():
-        try:
-            self.selenium.set_window_size(1024, 768)
             self.assertIs(field_title.is_displayed(), False)
-            self.selenium.set_window_size(767, 575)
+        with self.mobile_size():
             self.assertIs(field_title.is_displayed(), False)
-        finally:
-            self.selenium.set_window_size(current_size["width"], current_size["height"])
 
     def test_updating_related_objects_updates_fk_selects_except_autocompletes(self):
         from selenium.webdriver.common.by import By

tests/admin_widgets/tests.py

@@ -1083,7 +1083,6 @@ class DateTimePickerSeleniumTests(AdminWidgetSeleniumTestCase):
         """
         from selenium.webdriver.common.by import By
 
-        self.selenium.set_window_size(1024, 768)
         self.admin_login(username="super", password="secret", login_url="/")
 
         # Enter test data
@@ -1096,6 +1095,8 @@ class DateTimePickerSeleniumTests(AdminWidgetSeleniumTestCase):
         path = os.path.join(
             os.path.dirname(import_module("django.contrib.admin").__file__), "locale"
         )
+        url = reverse("admin:admin_widgets_member_change", args=(member.pk,))
+        with self.small_screen_size():
             for language_code, language_name in settings.LANGUAGES:
                 try:
                     catalog = gettext.translation("djangojs", path, [language_code])
@@ -1106,18 +1107,17 @@ class DateTimePickerSeleniumTests(AdminWidgetSeleniumTestCase):
                 else:
                     month_name = month_string
 
-            # Get the expected caption
+                # Get the expected caption.
                 may_translation = month_name
                 expected_caption = "{:s} {:d}".format(may_translation.upper(), 1984)
 
-            # Test with every locale
+                # Every locale.
                 with override_settings(LANGUAGE_CODE=language_code):
-                # Open a page that has a date picker widget
+                    # Open a page that has a date picker widget.
-                url = reverse("admin:admin_widgets_member_change", args=(member.pk,))
                     self.selenium.get(self.live_server_url + url)
-                # Click on the calendar icon
+                    # Click on the calendar icon.
                     self.selenium.find_element(By.ID, "calendarlink0").click()
-                # Make sure that the right month and year are displayed
+                    # The right month and year are displayed.
                     self.wait_for_text("#calendarin0 caption", expected_caption)
 
 
@@ -1416,10 +1416,10 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
     def test_basic(self):
         from selenium.webdriver.common.by import By
 
-        self.selenium.set_window_size(1024, 768)
         self.school.students.set([self.lisa, self.peter])
         self.school.alumni.set([self.lisa, self.peter])
 
+        with self.small_screen_size():
             self.admin_login(username="super", password="secret", login_url="/")
             self.selenium.get(
                 self.live_server_url
@@ -1430,7 +1430,8 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
             self.execute_basic_operations("vertical", "students")
             self.execute_basic_operations("horizontal", "alumni")
 
-        # Save and check that everything is properly stored in the database ---
+            # Save, everything should be stored properly stored in the
+            # database.
             self.selenium.find_element(By.XPATH, '//input[@value="Save"]').click()
             self.wait_page_ready()
         self.school = School.objects.get(id=self.school.id)  # Reload from database
@@ -1451,10 +1452,10 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
         from selenium.webdriver.common.by import By
         from selenium.webdriver.common.keys import Keys
 
-        self.selenium.set_window_size(1024, 768)
         self.school.students.set([self.lisa, self.peter])
         self.school.alumni.set([self.lisa, self.peter])
 
+        with self.small_screen_size():
             self.admin_login(username="super", password="secret", login_url="/")
             self.selenium.get(
                 self.live_server_url
@@ -1467,8 +1468,7 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
                 choose_link = "id_%s_add_link" % field_name
                 remove_link = "id_%s_remove_link" % field_name
                 input = self.selenium.find_element(By.ID, "id_%s_input" % field_name)
-
+                # Initial values.
-            # Initial values
                 self.assertSelectOptions(
                     from_box,
                     [
@@ -1480,16 +1480,14 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
                         str(self.john.id),
                     ],
                 )
-
+                # Typing in some characters filters out non-matching options.
-            # Typing in some characters filters out non-matching options
                 input.send_keys("a")
                 self.assertSelectOptions(
                     from_box, [str(self.arthur.id), str(self.jason.id)]
                 )
                 input.send_keys("R")
                 self.assertSelectOptions(from_box, [str(self.arthur.id)])
-
+                # Clearing the text box makes the other options reappear.
-            # Clearing the text box makes the other options reappear
                 input.send_keys([Keys.BACK_SPACE])
                 self.assertSelectOptions(
                     from_box, [str(self.arthur.id), str(self.jason.id)]
@@ -1507,7 +1505,6 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
                     ],
                 )
 
-            # -----------------------------------------------------------------
                 # Choosing a filtered option sends it properly to the 'to' box.
                 input.send_keys("a")
                 self.assertSelectOptions(
@@ -1527,8 +1524,12 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
 
                 self.select_option(to_box, str(self.lisa.id))
                 self.selenium.find_element(By.ID, remove_link).click()
-            self.assertSelectOptions(from_box, [str(self.arthur.id), str(self.lisa.id)])
+                self.assertSelectOptions(
-            self.assertSelectOptions(to_box, [str(self.peter.id), str(self.jason.id)])
+                    from_box, [str(self.arthur.id), str(self.lisa.id)]
+                )
+                self.assertSelectOptions(
+                    to_box, [str(self.peter.id), str(self.jason.id)]
+                )
 
                 input.send_keys([Keys.BACK_SPACE])  # Clear text box
                 self.assertSelectOptions(
@@ -1542,9 +1543,10 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
                         str(self.lisa.id),
                     ],
                 )
-            self.assertSelectOptions(to_box, [str(self.peter.id), str(self.jason.id)])
+                self.assertSelectOptions(
+                    to_box, [str(self.peter.id), str(self.jason.id)]
+                )
 
-            # -----------------------------------------------------------------
                 # Pressing enter on a filtered option sends it properly to
                 # the 'to' box.
                 self.select_option(to_box, str(self.jason.id))
@@ -1552,10 +1554,12 @@ class HorizontalVerticalFilterSeleniumTests(AdminWidgetSeleniumTestCase):
                 input.send_keys("ja")
                 self.assertSelectOptions(from_box, [str(self.jason.id)])
                 input.send_keys([Keys.ENTER])
-            self.assertSelectOptions(to_box, [str(self.peter.id), str(self.jason.id)])
+                self.assertSelectOptions(
+                    to_box, [str(self.peter.id), str(self.jason.id)]
+                )
                 input.send_keys([Keys.BACK_SPACE, Keys.BACK_SPACE])
 
-        # Save and check that everything is properly stored in the database ---
+            # Save, everything should be stored properly in the database.
             with self.wait_page_loaded():
                 self.selenium.find_element(By.XPATH, '//input[@value="Save"]').click()
         self.school = School.objects.get(id=self.school.id)  # Reload from database