Move check_mode setting to the proper location regardless of version

changelogs/fragments/check_mode.yaml

@@ -0,0 +1,3 @@
+---
+trivial:
+  - check_mode has been removed from play_context, set on task instead for unit tests

docs/ansible.utils.index_of_lookup.rst

@@ -44,6 +44,7 @@ Parameters
                     <a class="ansibleOptionLink" href="#parameter-" title="Permalink to this option"></a>
                     <div style="font-size: small">
                         <span style="color: purple">list</span>
+                         / <span style="color: purple">elements=raw</span>
                          / <span style="color: red">required</span>
                     </div>
                 </td>

tests/unit/plugins/action/test_fact_diff.py

@@ -25,7 +25,10 @@ except ImportError:
 class TestUpdate_Fact(unittest.TestCase):
     def setUp(self):
         task = MagicMock(Task)
+        # Ansible > 2.13 looks for check_mode in task
+        task.check_mode = False
         play_context = MagicMock()
+        # Ansible <= 2.13 looks for check_mode in play_context
         play_context.check_mode = False
         connection = MagicMock()
         fake_loader = {}

tests/unit/plugins/action/test_update_fact.py

@@ -81,7 +81,10 @@ INVALID_JINJA = [
 class TestUpdate_Fact(unittest.TestCase):
     def setUp(self):
         task = MagicMock(Task)
+        # Ansible > 2.13 looks for check_mode in task
+        task.check_mode = False
         play_context = MagicMock()
+        # Ansible <= 2.13 looks for check_mode in play_context
         play_context.check_mode = False
         connection = MagicMock()
         fake_loader = {}