chore(tests-backend): migrate snowflake and sqlite to unit tests (#18854)

* migrate snowflake and sqlite

* change structure to better match the other unit tests

Co-authored-by: Corbin Robb <corbin@Corbins-MacBook-Pro.local>

tests/unit_tests/db_engine_specs/test_sqlite.py

@@ -0,0 +1,90 @@
+# 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 datetime import datetime
+from unittest import mock
+
+import pytest
+from flask.ctx import AppContext
+
+from tests.unit_tests.fixtures.common import dttm
+
+
+def test_convert_dttm(app_context: AppContext, dttm: datetime) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    assert SqliteEngineSpec.convert_dttm("TEXT", dttm) == "'2019-01-02 03:04:05.678900'"
+
+
+def test_convert_dttm_lower(app_context: AppContext, dttm: datetime) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    assert SqliteEngineSpec.convert_dttm("text", dttm) == "'2019-01-02 03:04:05.678900'"
+
+
+def test_convert_dttm_invalid_type(app_context: AppContext, dttm: datetime) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    assert SqliteEngineSpec.convert_dttm("other", dttm) == None
+
+
+def test_get_all_datasource_names_table(app_context: AppContext) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    database = mock.MagicMock()
+    database.get_all_schema_names.return_value = ["schema1"]
+    table_names = ["table1", "table2"]
+    get_tables = mock.MagicMock(return_value=table_names)
+    database.get_all_table_names_in_schema = get_tables
+    result = SqliteEngineSpec.get_all_datasource_names(database, "table")
+
+    assert result == table_names
+    get_tables.assert_called_once_with(
+        schema="schema1",
+        force=True,
+        cache=database.table_cache_enabled,
+        cache_timeout=database.table_cache_timeout,
+    )
+
+
+def test_get_all_datasource_names_view(app_context: AppContext) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    database = mock.MagicMock()
+    database.get_all_schema_names.return_value = ["schema1"]
+    views_names = ["view1", "view2"]
+    get_views = mock.MagicMock(return_value=views_names)
+    database.get_all_view_names_in_schema = get_views
+    result = SqliteEngineSpec.get_all_datasource_names(database, "view")
+
+    assert result == views_names
+    get_views.assert_called_once_with(
+        schema="schema1",
+        force=True,
+        cache=database.table_cache_enabled,
+        cache_timeout=database.table_cache_timeout,
+    )
+
+
+def test_get_all_datasource_names_invalid_type(app_context: AppContext) -> None:
+    from superset.db_engine_specs.sqlite import SqliteEngineSpec
+
+    database = mock.MagicMock()
+    database.get_all_schema_names.return_value = ["schema1"]
+    invalid_type = "asdf"
+
+    with pytest.raises(Exception):
+        SqliteEngineSpec.get_all_datasource_names(database, invalid_type)