Raise TypeError on bare test decorator usage and add regression tests (#3649)

* Raise TypeError on bare @skip_if_windows, @requires_crt, @skip_if_crt usage and add regression tests

* Rename test_test_decorators.py to test_decorators.py

* Add license to the new file tset_decorators.py

Author: Alan4506

tests/__init__.py

@@ -72,6 +72,11 @@ def skip_if_windows(reason):
         def test_some_non_windows_stuff(self):
             self.assertEqual(...)
     """
+    if callable(reason):
+        raise TypeError(
+            "Use @skip_if_windows('reason') with parentheses, "
+            "not bare @skip_if_windows"
+        )
 
     def decorator(func):
         return unittest.skipIf(
@@ -82,6 +87,10 @@ def decorator(func):
 
 
 def requires_crt(reason=None):
+    if callable(reason):
+        raise TypeError(
+            "Use @requires_crt() with parentheses, not bare @requires_crt"
+        )
     if reason is None:
         reason = "Test requires awscrt to be installed"
 
@@ -92,6 +101,10 @@ def decorator(func):
 
 
 def skip_if_crt(reason=None):
+    if callable(reason):
+        raise TypeError(
+            "Use @skip_if_crt() with parentheses, not bare @skip_if_crt"
+        )
     if reason is None:
         reason = "Test requires awscrt to NOT be installed"
 

tests/unit/test_decorators.py

@@ -0,0 +1,101 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License").
+# You may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from unittest import mock
+
+import pytest
+
+from tests import requires_crt, skip_if_crt, skip_if_windows
+
+
+class TestSkipIfWindows:
+    def test_bare_skip_if_windows_fails_immediately(self):
+        with pytest.raises(TypeError):
+
+            @skip_if_windows
+            def my_test():
+                pass
+
+    def test_skip_if_windows_skips_on_windows(self):
+        with mock.patch('tests.platform') as mock_platform:
+            mock_platform.system.return_value = 'Windows'
+
+            @skip_if_windows('Not supported on Windows')
+            def my_test():
+                assert False
+
+            assert getattr(my_test, '__unittest_skip__', False) is True
+
+    def test_skip_if_windows_runs_on_non_windows(self):
+        with mock.patch('tests.platform') as mock_platform:
+            mock_platform.system.return_value = 'Linux'
+
+            @skip_if_windows('Not supported on Windows')
+            def my_test():
+                pass
+
+            assert getattr(my_test, '__unittest_skip__', False) is False
+
+
+class TestRequiresCrt:
+    def test_bare_requires_crt_fails_immediately(self):
+        with pytest.raises(TypeError):
+
+            @requires_crt
+            def my_test():
+                pass
+
+    def test_requires_crt_skips_when_no_crt(self):
+        with mock.patch('tests.HAS_CRT', False):
+
+            @requires_crt()
+            def my_test():
+                assert False
+
+            assert getattr(my_test, '__unittest_skip__', False) is True
+
+    def test_requires_crt_runs_when_crt_available(self):
+        with mock.patch('tests.HAS_CRT', True):
+
+            @requires_crt()
+            def my_test():
+                pass
+
+            assert getattr(my_test, '__unittest_skip__', False) is False
+
+
+class TestSkipIfCrt:
+    def test_bare_skip_if_crt_fails_immediately(self):
+        with pytest.raises(TypeError):
+
+            @skip_if_crt
+            def my_test():
+                pass
+
+    def test_skip_if_crt_skips_when_crt_available(self):
+        with mock.patch('tests.HAS_CRT', True):
+
+            @skip_if_crt()
+            def my_test():
+                assert False
+
+            assert getattr(my_test, '__unittest_skip__', False) is True
+
+    def test_skip_if_crt_runs_when_no_crt(self):
+        with mock.patch('tests.HAS_CRT', False):
+
+            @skip_if_crt()
+            def my_test():
+                pass
+
+            assert getattr(my_test, '__unittest_skip__', False) is False