chore(db_engine_specs): clean up column spec logic and add tests (#22871)

tests/unit_tests/db_engine_specs/test_oracle.py

@@ -0,0 +1,113 @@
+# 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 typing import Optional, Union
+from unittest import mock
+
+import pytest
+from sqlalchemy import column, types
+from sqlalchemy.dialects import oracle
+from sqlalchemy.dialects.oracle import DATE, NVARCHAR, VARCHAR
+from sqlalchemy.sql import quoted_name
+
+from tests.unit_tests.db_engine_specs.utils import assert_convert_dttm
+from tests.unit_tests.fixtures.common import dttm
+
+
+@pytest.mark.parametrize(
+    "column_name,expected_result",
+    [
+        ("This_Is_32_Character_Column_Name", "3b26974078683be078219674eeb8f5"),
+        ("snake_label", "snake_label"),
+        ("camelLabel", "camelLabel"),
+    ],
+)
+def test_oracle_sqla_column_name_length_exceeded(
+    column_name: str, expected_result: Union[str, quoted_name]
+) -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec
+
+    label = OracleEngineSpec.make_label_compatible(column_name)
+    assert isinstance(label, quoted_name)
+    assert label.quote is True
+    assert label == expected_result
+
+
+def test_oracle_time_expression_reserved_keyword_1m_grain() -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec
+
+    col = column("decimal")
+    expr = OracleEngineSpec.get_timestamp_expr(col, None, "P1M")
+    result = str(expr.compile(dialect=oracle.dialect()))
+    assert result == "TRUNC(CAST(\"decimal\" as DATE), 'MONTH')"
+
+
+@pytest.mark.parametrize(
+    "sqla_type,expected_result",
+    [
+        (DATE(), "DATE"),
+        (VARCHAR(length=255), "VARCHAR(255 CHAR)"),
+        (VARCHAR(length=255, collation="utf8"), "VARCHAR(255 CHAR)"),
+        (NVARCHAR(length=128), "NVARCHAR2(128)"),
+    ],
+)
+def test_column_datatype_to_string(
+    sqla_type: types.TypeEngine, expected_result: str
+) -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec
+
+    assert (
+        OracleEngineSpec.column_datatype_to_string(sqla_type, oracle.dialect())
+        == expected_result
+    )
+
+
+def test_fetch_data_no_description() -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec
+
+    cursor = mock.MagicMock()
+    cursor.description = []
+    assert OracleEngineSpec.fetch_data(cursor) == []
+
+
+def test_fetch_data() -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec
+
+    cursor = mock.MagicMock()
+    result = ["a", "b"]
+    cursor.fetchall.return_value = result
+    assert OracleEngineSpec.fetch_data(cursor) == result
+
+
+@pytest.mark.parametrize(
+    "target_type,expected_result",
+    [
+        ("Date", "TO_DATE('2019-01-02', 'YYYY-MM-DD')"),
+        ("DateTime", """TO_DATE('2019-01-02T03:04:05', 'YYYY-MM-DD"T"HH24:MI:SS')"""),
+        (
+            "TimeStamp",
+            """TO_TIMESTAMP('2019-01-02T03:04:05.678900', 'YYYY-MM-DD"T"HH24:MI:SS.ff6')""",
+        ),
+        ("Other", None),
+    ],
+)
+def test_convert_dttm(
+    target_type: str, expected_result: Optional[str], dttm: datetime
+) -> None:
+    from superset.db_engine_specs.oracle import OracleEngineSpec as spec
+
+    assert_convert_dttm(spec, target_type, expected_result, dttm)