From 3b730d977581905bff2c825dc6cc51473326b0c9 Mon Sep 17 00:00:00 2001
From: Gil Forsyth <gil@forsyth.dev>
Date: Tue, 28 Nov 2023 13:35:13 -0500
Subject: [PATCH] refactor(tests): remove test rounding mixins

---
 ibis/backends/bigquery/tests/conftest.py   |  4 +-
 ibis/backends/clickhouse/tests/conftest.py |  5 ++-
 ibis/backends/datafusion/tests/conftest.py |  4 +-
 ibis/backends/druid/tests/conftest.py      |  5 ++-
 ibis/backends/duckdb/tests/conftest.py     |  4 +-
 ibis/backends/flink/tests/conftest.py      |  4 +-
 ibis/backends/impala/tests/conftest.py     |  4 +-
 ibis/backends/mssql/tests/conftest.py      |  5 ++-
 ibis/backends/mysql/tests/conftest.py      |  5 ++-
 ibis/backends/oracle/tests/conftest.py     |  5 ++-
 ibis/backends/pandas/tests/conftest.py     |  5 ++-
 ibis/backends/polars/tests/conftest.py     |  4 +-
 ibis/backends/postgres/tests/conftest.py   |  5 ++-
 ibis/backends/pyspark/tests/conftest.py    |  4 +-
 ibis/backends/snowflake/tests/conftest.py  |  4 +-
 ibis/backends/sqlite/tests/conftest.py     |  4 +-
 ibis/backends/tests/base.py                | 45 +++++++++-------------
 ibis/backends/trino/tests/conftest.py      |  4 +-
 18 files changed, 59 insertions(+), 61 deletions(-)

diff --git a/ibis/backends/bigquery/tests/conftest.py b/ibis/backends/bigquery/tests/conftest.py
index d55785bb6def..e842a4f47024 100644
--- a/ibis/backends/bigquery/tests/conftest.py
+++ b/ibis/backends/bigquery/tests/conftest.py
@@ -15,7 +15,7 @@
 from ibis.backends.bigquery import EXTERNAL_DATA_SCOPES, Backend
 from ibis.backends.bigquery.datatypes import BigQuerySchema
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import json_types, non_null_array_types, struct_types, win
 
 DATASET_ID = "ibis_gbq_testing"
@@ -25,7 +25,7 @@
 PROJECT_ID_ENV_VAR = "GOOGLE_BIGQUERY_PROJECT_ID"
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     """Backend-specific class with information for testing."""
 
     supports_divide_by_zero = True
diff --git a/ibis/backends/clickhouse/tests/conftest.py b/ibis/backends/clickhouse/tests/conftest.py
index 7b1d5e65307f..618f97a3b633 100644
--- a/ibis/backends/clickhouse/tests/conftest.py
+++ b/ibis/backends/clickhouse/tests/conftest.py
@@ -9,7 +9,7 @@
 import ibis
 import ibis.expr.types as ir
 from ibis import util
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -22,7 +22,7 @@
 IBIS_TEST_CLICKHOUSE_DB = os.environ.get("IBIS_TEST_DATA_DB", "ibis_testing")
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     check_dtype = False
     supports_window_operations = False
     returned_timestamp_unit = "s"
@@ -30,6 +30,7 @@ class TestConf(ServiceBackendTest, RoundHalfToEven):
     supports_floating_modulus = False
     supports_json = False
     force_sort_before_comparison = True
+    rounding_method = "half_to_even"
     data_volume = "/var/lib/clickhouse/user_files/ibis"
     service_name = "clickhouse"
     deps = ("clickhouse_connect",)
diff --git a/ibis/backends/datafusion/tests/conftest.py b/ibis/backends/datafusion/tests/conftest.py
index 1e20f4238471..49adf83e6fb8 100644
--- a/ibis/backends/datafusion/tests/conftest.py
+++ b/ibis/backends/datafusion/tests/conftest.py
@@ -6,11 +6,11 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import array_types, win
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     # check_names = False
     # supports_divide_by_zero = True
     # returned_timestamp_unit = 'ns'
diff --git a/ibis/backends/druid/tests/conftest.py b/ibis/backends/druid/tests/conftest.py
index 88704efd5141..b95227a9aa61 100644
--- a/ibis/backends/druid/tests/conftest.py
+++ b/ibis/backends/druid/tests/conftest.py
@@ -12,7 +12,7 @@
 from requests import Session
 
 import ibis
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -89,7 +89,7 @@ def run_query(session: Session, query: str) -> None:
         time.sleep(REQUEST_INTERVAL)
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     # druid has the same rounding behavior as postgres
     check_dtype = False
     supports_window_operations = False
@@ -99,6 +99,7 @@ class TestConf(ServiceBackendTest, RoundHalfToEven):
     native_bool = True
     supports_structs = False
     supports_json = False  # it does, but we haven't implemented it
+    rounding_method = "half_to_even"
     service_name = "druid-middlemanager"
     deps = ("pydruid.db.sqlalchemy",)
 
diff --git a/ibis/backends/duckdb/tests/conftest.py b/ibis/backends/duckdb/tests/conftest.py
index 8ef6c9f6132c..bc62b94fe034 100644
--- a/ibis/backends/duckdb/tests/conftest.py
+++ b/ibis/backends/duckdb/tests/conftest.py
@@ -6,7 +6,7 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.conftest import SANDBOXED
 
 if TYPE_CHECKING:
@@ -15,7 +15,7 @@
     from ibis.backends.base import BaseBackend
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_map = True
     deps = "duckdb", "duckdb_engine"
     stateful = False
diff --git a/ibis/backends/flink/tests/conftest.py b/ibis/backends/flink/tests/conftest.py
index 46497fd5096f..92b412ebbeb0 100644
--- a/ibis/backends/flink/tests/conftest.py
+++ b/ibis/backends/flink/tests/conftest.py
@@ -6,10 +6,10 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_structs = False
     force_sort_before_comparison = True
     deps = "pandas", "pyflink"
diff --git a/ibis/backends/impala/tests/conftest.py b/ibis/backends/impala/tests/conftest.py
index 0d37399e1451..4e46b646c6e1 100644
--- a/ibis/backends/impala/tests/conftest.py
+++ b/ibis/backends/impala/tests/conftest.py
@@ -18,12 +18,12 @@
 from ibis import options, util
 from ibis.backends.conftest import TEST_TABLES
 from ibis.backends.impala.compiler import ImpalaCompiler, ImpalaExprTranslator
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import win
 from ibis.tests.expr.mocks import MockBackend
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_arrays = True
     supports_arrays_outside_of_select = False
     check_dtype = False
diff --git a/ibis/backends/mssql/tests/conftest.py b/ibis/backends/mssql/tests/conftest.py
index 6f8ef88d58c6..87161387bb72 100644
--- a/ibis/backends/mssql/tests/conftest.py
+++ b/ibis/backends/mssql/tests/conftest.py
@@ -8,7 +8,7 @@
 
 import ibis
 from ibis.backends.conftest import init_database
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -21,7 +21,7 @@
 IBIS_TEST_MSSQL_DB = os.environ.get("IBIS_TEST_MSSQL_DATABASE", "ibis_testing")
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     # MSSQL has the same rounding behavior as postgres
     check_dtype = False
     supports_window_operations = False
@@ -30,6 +30,7 @@ class TestConf(ServiceBackendTest, RoundHalfToEven):
     supports_arrays_outside_of_select = supports_arrays
     supports_structs = False
     supports_json = False
+    rounding_method = "half_to_even"
     service_name = "mssql"
     deps = "pymssql", "sqlalchemy"
 
diff --git a/ibis/backends/mysql/tests/conftest.py b/ibis/backends/mysql/tests/conftest.py
index d2e77d47704a..8c0ad8007051 100644
--- a/ibis/backends/mysql/tests/conftest.py
+++ b/ibis/backends/mysql/tests/conftest.py
@@ -9,7 +9,7 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES, init_database
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -22,7 +22,7 @@
 IBIS_TEST_MYSQL_DB = os.environ.get("IBIS_TEST_MYSQL_DATABASE", "ibis_testing")
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     # mysql has the same rounding behavior as postgres
     check_dtype = False
     returned_timestamp_unit = "s"
@@ -30,6 +30,7 @@ class TestConf(ServiceBackendTest, RoundHalfToEven):
     supports_arrays_outside_of_select = supports_arrays
     native_bool = False
     supports_structs = False
+    rounding_method = "half_to_even"
     service_name = "mysql"
     deps = "pymysql", "sqlalchemy"
 
diff --git a/ibis/backends/oracle/tests/conftest.py b/ibis/backends/oracle/tests/conftest.py
index be4688b46f14..79d1de373bfd 100644
--- a/ibis/backends/oracle/tests/conftest.py
+++ b/ibis/backends/oracle/tests/conftest.py
@@ -11,7 +11,7 @@
 import sqlalchemy as sa
 
 import ibis
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -29,7 +29,7 @@
 # where ORACLE_DB is the same name you used in the docker-compose file.
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     check_dtype = False
     supports_window_operations = False
     returned_timestamp_unit = "s"
@@ -40,6 +40,7 @@ class TestConf(ServiceBackendTest, RoundHalfToEven):
     native_bool = False
     supports_structs = False
     supports_json = False
+    rounding_method = "half_to_even"
     data_volume = "/opt/oracle/data"
     service_name = "oracle"
     deps = "oracledb", "sqlalchemy"
diff --git a/ibis/backends/pandas/tests/conftest.py b/ibis/backends/pandas/tests/conftest.py
index 4c6bdd567d87..8aa998871d2a 100644
--- a/ibis/backends/pandas/tests/conftest.py
+++ b/ibis/backends/pandas/tests/conftest.py
@@ -4,16 +4,17 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundHalfToEven
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import array_types, json_types, struct_types, win
 
 
-class TestConf(BackendTest, RoundHalfToEven):
+class TestConf(BackendTest):
     check_names = False
     supported_to_timestamp_units = BackendTest.supported_to_timestamp_units | {"ns"}
     supports_divide_by_zero = True
     returned_timestamp_unit = "ns"
     stateful = False
+    rounding_method = "half_to_even"
     deps = ("pandas",)
 
     def _load_data(self, **_: Any) -> None:
diff --git a/ibis/backends/polars/tests/conftest.py b/ibis/backends/polars/tests/conftest.py
index 9eb1d62cbe9f..a337ea16fbac 100644
--- a/ibis/backends/polars/tests/conftest.py
+++ b/ibis/backends/polars/tests/conftest.py
@@ -7,11 +7,11 @@
 
 import ibis
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import array_types, struct_types, win
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_structs = True
     supports_json = False
     reduction_tolerance = 1e-3
diff --git a/ibis/backends/postgres/tests/conftest.py b/ibis/backends/postgres/tests/conftest.py
index bb8237e4379e..23d3c8f2d27d 100644
--- a/ibis/backends/postgres/tests/conftest.py
+++ b/ibis/backends/postgres/tests/conftest.py
@@ -21,7 +21,7 @@
 
 import ibis
 from ibis.backends.conftest import init_database
-from ibis.backends.tests.base import RoundHalfToEven, ServiceBackendTest
+from ibis.backends.tests.base import ServiceBackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -42,12 +42,13 @@
 )
 
 
-class TestConf(ServiceBackendTest, RoundHalfToEven):
+class TestConf(ServiceBackendTest):
     # postgres rounds half to even for double precision and half away from zero
     # for numeric and decimal
 
     returned_timestamp_unit = "s"
     supports_structs = False
+    rounding_method = "half_to_even"
     service_name = "postgres"
     deps = "psycopg2", "sqlalchemy"
 
diff --git a/ibis/backends/pyspark/tests/conftest.py b/ibis/backends/pyspark/tests/conftest.py
index db49960382e2..03ec6aa1a715 100644
--- a/ibis/backends/pyspark/tests/conftest.py
+++ b/ibis/backends/pyspark/tests/conftest.py
@@ -11,7 +11,7 @@
 import ibis
 from ibis import util
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.backends.tests.data import json_types, win
 
 
@@ -19,7 +19,7 @@ def set_pyspark_database(con, database):
     con._session.catalog.setCurrentDatabase(database)
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supported_to_timestamp_units = {"s"}
     deps = ("pyspark",)
 
diff --git a/ibis/backends/snowflake/tests/conftest.py b/ibis/backends/snowflake/tests/conftest.py
index 4faac50223a0..0ff7ce7cf586 100644
--- a/ibis/backends/snowflake/tests/conftest.py
+++ b/ibis/backends/snowflake/tests/conftest.py
@@ -13,7 +13,7 @@
 import ibis
 from ibis.backends.conftest import TEST_TABLES
 from ibis.backends.snowflake.datatypes import SnowflakeType
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 from ibis.formats.pyarrow import PyArrowSchema
 
 if TYPE_CHECKING:
@@ -63,7 +63,7 @@ def copy_into(con, data_dir: Path, table: str) -> None:
     )
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_map = True
     default_identifier_case_fn = staticmethod(str.upper)
     deps = ("snowflake.connector", "snowflake.sqlalchemy")
diff --git a/ibis/backends/sqlite/tests/conftest.py b/ibis/backends/sqlite/tests/conftest.py
index a1a52db6f384..3577061e9ab3 100644
--- a/ibis/backends/sqlite/tests/conftest.py
+++ b/ibis/backends/sqlite/tests/conftest.py
@@ -11,10 +11,10 @@
 import ibis
 import ibis.expr.types as ir
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     supports_arrays = False
     supports_arrays_outside_of_select = supports_arrays
     supports_window_operations = True
diff --git a/ibis/backends/tests/base.py b/ibis/backends/tests/base.py
index 2890b485087f..4c1c52749889 100644
--- a/ibis/backends/tests/base.py
+++ b/ibis/backends/tests/base.py
@@ -20,33 +20,6 @@
     import ibis.expr.types as ir
 
 
-# TODO: Merge into BackendTest, #2564
-class RoundingConvention:
-    @staticmethod
-    @abc.abstractmethod
-    def round(series: pd.Series, decimals: int = 0) -> pd.Series:
-        """Round a series to `decimals` number of decimal values."""
-
-
-# TODO: Merge into BackendTest, #2564
-class RoundAwayFromZero(RoundingConvention):
-    @staticmethod
-    def round(series: pd.Series, decimals: int = 0) -> pd.Series:
-        if not decimals:
-            return (-(np.sign(series)) * np.ceil(-(series.abs()) - 0.5)).astype(
-                np.int64
-            )
-        return series.round(decimals=decimals)
-
-
-# TODO: Merge into BackendTest, #2564
-class RoundHalfToEven(RoundingConvention):
-    @staticmethod
-    def round(series: pd.Series, decimals: int = 0) -> pd.Series:
-        result = series.round(decimals=decimals)
-        return result if decimals else result.astype(np.int64)
-
-
 class BackendTest(abc.ABC):
     check_dtype = True
     check_names = True
@@ -67,6 +40,7 @@ class BackendTest(abc.ABC):
     service_name = None
     supports_tpch = False
     force_sort_before_comparison = False
+    rounding_method = "away_from_zero"
 
     @property
     @abc.abstractmethod
@@ -186,6 +160,23 @@ def assert_frame_equal(
         kwargs.setdefault("check_dtype", cls.check_dtype)
         tm.assert_frame_equal(left, right, *args, **kwargs)
 
+    @classmethod
+    def round(cls, series: pd.Series, decimals: int = 0) -> pd.Series:
+        return getattr(cls, cls.rounding_method)(series, decimals)
+
+    @staticmethod
+    def away_from_zero(series: pd.Series, decimals: int = 0) -> pd.Series:
+        if not decimals:
+            return (-(np.sign(series)) * np.ceil(-(series.abs()) - 0.5)).astype(
+                np.int64
+            )
+        return series.round(decimals=decimals)
+
+    @staticmethod
+    def half_to_even(series: pd.Series, decimals: int = 0) -> pd.Series:
+        result = series.round(decimals=decimals)
+        return result if decimals else result.astype(np.int64)
+
     @staticmethod
     def default_series_rename(series: pd.Series, name: str = "tmp") -> pd.Series:
         return series.rename(name)
diff --git a/ibis/backends/trino/tests/conftest.py b/ibis/backends/trino/tests/conftest.py
index ac9e7185a599..6410ab0cb64e 100644
--- a/ibis/backends/trino/tests/conftest.py
+++ b/ibis/backends/trino/tests/conftest.py
@@ -11,7 +11,7 @@
 import ibis.expr.datatypes as dt
 import ibis.selectors as s
 from ibis.backends.conftest import TEST_TABLES
-from ibis.backends.tests.base import BackendTest, RoundAwayFromZero
+from ibis.backends.tests.base import BackendTest
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -32,7 +32,7 @@
 )
 
 
-class TestConf(BackendTest, RoundAwayFromZero):
+class TestConf(BackendTest):
     # trino rounds half to even for double precision and half away from zero
     # for numeric and decimal