webdriver: uplift is_fullscreen as helper

To be able to reuse is_fullscreen() in other tests, we need to
uplift it to the support.helpers package.

Depends on D8407

Differential Revision: https://phabricator.services.mozilla.com/D8408

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1492499
gecko-commit: cbca19a1e3f4dfa31d45c00d4ef1de1b459cd16a
gecko-integration-branch: autoland
gecko-reviewers: automatedtester

webdriver/tests/fullscreen_window/fullscreen.py

@@ -1,22 +1,12 @@
 from tests.support.asserts import assert_error, assert_success
+from tests.support.helpers import is_fullscreen
 
 
 def fullscreen(session):
     return session.transport.send(
         "POST", "session/{session_id}/window/fullscreen".format(**vars(session)))
 
 
-def is_fullscreen(session):
-    # At the time of writing, WebKit does not conform to the
-    # Fullscreen API specification.
-    #
-    # Remove the prefixed fallback when
-    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
-    return session.execute_script("""
-        return !!(window.fullScreen || document.webkitIsFullScreen)
-        """)
-
-
 def test_no_browsing_context(session, closed_window):
     response = fullscreen(session)
     assert_error(response, "no such window")

webdriver/tests/fullscreen_window/user_prompts.py

@@ -3,24 +3,14 @@
 import pytest
 
 from tests.support.asserts import assert_dialog_handled, assert_error, assert_success
+from tests.support.helpers import is_fullscreen
 
 
 def fullscreen(session):
     return session.transport.send(
         "POST", "session/{session_id}/window/fullscreen".format(**vars(session)))
 
 
-def is_fullscreen(session):
-    # At the time of writing, WebKit does not conform to the
-    # Fullscreen API specification.
-    #
-    # Remove the prefixed fallback when
-    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
-    return session.execute_script("""
-        return !!(window.fullScreen || document.webkitIsFullScreen)
-        """)
-
-
 @pytest.fixture
 def check_user_prompt_closed_without_exception(session, create_dialog):
     def check_user_prompt_closed_without_exception(dialog_type, retval):

webdriver/tests/maximize_window/maximize.py

@@ -1,22 +1,12 @@
 from tests.support.asserts import assert_error, assert_success
+from tests.support.helpers import is_fullscreen
 
 
 def maximize(session):
     return session.transport.send(
         "POST", "session/{session_id}/window/maximize".format(**vars(session)))
 
 
-def is_fullscreen(session):
-    # At the time of writing, WebKit does not conform to the
-    # Fullscreen API specification.
-    #
-    # Remove the prefixed fallback when
-    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
-    return session.execute_script("""
-        return !!(window.fullScreen || document.webkitIsFullScreen)
-        """)
-
-
 def test_no_browsing_context(session, closed_window):
     response = maximize(session)
     assert_error(response, "no such window")

webdriver/tests/minimize_window/minimize.py

@@ -1,22 +1,12 @@
 from tests.support.asserts import assert_error, assert_success
+from tests.support.helpers import is_fullscreen
 
 
 def minimize(session):
     return session.transport.send(
         "POST", "session/{session_id}/window/minimize".format(**vars(session)))
 
 
-def is_fullscreen(session):
-    # At the time of writing, WebKit does not conform to the
-    # Fullscreen API specification.
-    #
-    # Remove the prefixed fallback when
-    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
-    return session.execute_script("""
-        return !!(window.fullScreen || document.webkitIsFullScreen)
-        """)
-
-
 def is_minimized(session):
     return session.execute_script("return document.hidden")
 

webdriver/tests/set_window_rect/set.py

@@ -5,6 +5,7 @@
 from webdriver.transport import Response
 
 from tests.support.asserts import assert_error, assert_success
+from tests.support.helpers import is_fullscreen
 
 
 def set_window_rect(session, rect):
@@ -13,17 +14,6 @@ def set_window_rect(session, rect):
         rect)
 
 
-def is_fullscreen(session):
-    # At the time of writing, WebKit does not conform to the
-    # Fullscreen API specification.
-    #
-    # Remove the prefixed fallback when
-    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
-    return session.execute_script("""
-        return !!(window.fullScreen || document.webkitIsFullScreen)
-        """)
-
-
 def test_null_parameter_value(session, http):
     path = "/session/{session_id}/window/rect".format(**vars(session))
     with http.post(path, None) as response:

webdriver/tests/support/helpers.py

@@ -119,6 +119,17 @@ def is_element_in_viewport(session, element):
     """, args=(element,))
 
 
+def is_fullscreen(session):
+    # At the time of writing, WebKit does not conform to the
+    # Fullscreen API specification.
+    #
+    # Remove the prefixed fallback when
+    # https://bugs.webkit.org/show_bug.cgi?id=158125 is fixed.
+    return session.execute_script("""
+        return !!(window.fullScreen || document.webkitIsFullScreen)
+        """)
+
+
 def document_dimensions(session):
     return tuple(session.execute_script("""
         let {devicePixelRatio} = window;