refactor(tests): decouple unittests from integration tests (#15473)

* refactor move all tests to be under integration_tests package

* refactor decouple unittests from integration tests - commands

* add unit_tests package

* fix celery_tests.py

* fix wrong FIXTURES_DIR value

tests/integration_tests/feature_flag_tests.py

@@ -0,0 +1,40 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.mock import patch
+
+from superset import is_feature_enabled
+from tests.integration_tests.base_tests import SupersetTestCase
+
+
+class TestFeatureFlag(SupersetTestCase):
+    @patch.dict(
+        "superset.extensions.feature_flag_manager._feature_flags",
+        {"FOO": True},
+        clear=True,
+    )
+    def test_existing_feature_flags(self):
+        self.assertTrue(is_feature_enabled("FOO"))
+
+    @patch.dict(
+        "superset.extensions.feature_flag_manager._feature_flags", {}, clear=True
+    )
+    def test_nonexistent_feature_flags(self):
+        self.assertFalse(is_feature_enabled("FOO"))
+
+    def test_feature_flags(self):
+        self.assertEqual(is_feature_enabled("foo"), "bar")
+        self.assertEqual(is_feature_enabled("super"), "set")