Improve coverage of role unit tests (#80695)

test/units/playbook/role/test_include_role.py

@@ -108,8 +108,6 @@ class TestIncludeRole(unittest.TestCase):
                 # skip meta: role_complete
                 continue
             role = task._role
-            if not role:
-                continue
 
             yield (role.get_name(),
                    self.var_manager.get_vars(play=play, task=task))
@@ -201,7 +199,7 @@ class TestIncludeRole(unittest.TestCase):
                 self.assertEqual(task_vars.get('l3_variable'), 'l3-main')
                 self.assertEqual(task_vars.get('test_variable'), 'l3-main')
             else:
-                self.fail()
+                self.fail()  # pragma: nocover
         self.assertFalse(expected_roles)
 
     @patch('ansible.playbook.role.definition.unfrackpath',
@@ -247,5 +245,5 @@ class TestIncludeRole(unittest.TestCase):
                 self.assertEqual(task_vars.get('l3_variable'), 'l3-alt')
                 self.assertEqual(task_vars.get('test_variable'), 'l3-alt')
             else:
-                self.fail()
+                self.fail()  # pragma: nocover
         self.assertFalse(expected_roles)

test/units/playbook/role/test_role.py

@@ -21,6 +21,8 @@ __metaclass__ = type
 
 from collections.abc import Container
 
+import pytest
+
 from units.compat import unittest
 from unittest.mock import patch, MagicMock
 
@@ -42,12 +44,9 @@ class TestHashParams(unittest.TestCase):
         self._assert_set(res)
         self._assert_hashable(res)
 
-    def _assert_hashable(self, res):
-        a_dict = {}
-        try:
-            a_dict[res] = res
-        except TypeError as e:
-            self.fail('%s is not hashable: %s' % (res, e))
+    @staticmethod
+    def _assert_hashable(res):
+        hash(res)
 
     def _assert_set(self, res):
         self.assertIsInstance(res, frozenset)
@@ -87,36 +86,28 @@ class TestHashParams(unittest.TestCase):
 
     def test_generator(self):
         def my_generator():
-            for i in ['a', 1, None, {}]:
-                yield i
+            yield
 
         params = my_generator()
         res = hash_params(params)
         self._assert_hashable(res)
+        assert list(params)
 
     def test_container_but_not_iterable(self):
         # This is a Container that is not iterable, which is unlikely but...
         class MyContainer(Container):
-            def __init__(self, some_thing):
-                self.data = []
-                self.data.append(some_thing)
+            def __init__(self, _some_thing):
+                pass
 
             def __contains__(self, item):
-                return item in self.data
-
-            def __hash__(self):
-                return hash(self.data)
-
-            def __len__(self):
-                return len(self.data)
+                """Implementation omitted, since it will never be called."""
 
-            def __call__(self):
-                return False
+        params = MyContainer('foo bar')
 
-        foo = MyContainer('foo bar')
-        params = foo
+        with pytest.raises(TypeError) as ex:
+            hash_params(params)
 
-        self.assertRaises(TypeError, hash_params, params)
+        assert ex.value.args == ("'MyContainer' object is not iterable",)
 
     def test_param_dict_dupe_values(self):
         params1 = {'foo': False}