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/annotation_layers/fixtures.py

@@ -0,0 +1,101 @@
+# 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.
+# isort:skip_file
+import pytest
+from datetime import datetime
+from typing import Optional
+
+from superset import db
+from superset.models.annotations import Annotation, AnnotationLayer
+
+from tests.integration_tests.test_app import app
+
+
+ANNOTATION_LAYERS_COUNT = 10
+ANNOTATIONS_COUNT = 5
+
+
+def get_start_dttm(annotation_id: int) -> datetime:
+    return datetime(1990 + annotation_id, 1, 1)
+
+
+def get_end_dttm(annotation_id: int) -> datetime:
+    return datetime(1990 + annotation_id, 7, 1)
+
+
+def _insert_annotation_layer(name: str = "", descr: str = "") -> AnnotationLayer:
+    annotation_layer = AnnotationLayer(name=name, descr=descr,)
+    db.session.add(annotation_layer)
+    db.session.commit()
+    return annotation_layer
+
+
+def _insert_annotation(
+    layer: AnnotationLayer,
+    short_descr: str,
+    long_descr: str,
+    json_metadata: Optional[str] = "",
+    start_dttm: Optional[datetime] = None,
+    end_dttm: Optional[datetime] = None,
+) -> Annotation:
+    annotation = Annotation(
+        layer=layer,
+        short_descr=short_descr,
+        long_descr=long_descr,
+        json_metadata=json_metadata,
+        start_dttm=start_dttm,
+        end_dttm=end_dttm,
+    )
+    db.session.add(annotation)
+    db.session.commit()
+    return annotation
+
+
+@pytest.fixture()
+def create_annotation_layers():
+    """
+    Creates ANNOTATION_LAYERS_COUNT-1 layers with no annotations
+    and a final one with ANNOTATION_COUNT childs
+    :return:
+    """
+    with app.app_context():
+        annotation_layers = []
+        annotations = []
+        for cx in range(ANNOTATION_LAYERS_COUNT - 1):
+            annotation_layers.append(
+                _insert_annotation_layer(name=f"name{cx}", descr=f"descr{cx}")
+            )
+        layer_with_annotations = _insert_annotation_layer("layer_with_annotations")
+        annotation_layers.append(layer_with_annotations)
+        for cx in range(ANNOTATIONS_COUNT):
+            annotations.append(
+                _insert_annotation(
+                    layer_with_annotations,
+                    short_descr=f"short_descr{cx}",
+                    long_descr=f"long_descr{cx}",
+                    start_dttm=get_start_dttm(cx),
+                    end_dttm=get_end_dttm(cx),
+                )
+            )
+        yield annotation_layers
+
+        # rollback changes
+        for annotation_layer in annotation_layers:
+            db.session.delete(annotation_layer)
+        for annotation in annotations:
+            db.session.delete(annotation)
+        db.session.commit()