Fix unit tests on old pandas

Author: tswast

tests/unit/test_gbq.py

@@ -1,21 +1,26 @@
 # -*- coding: utf-8 -*-
 
-import pandas.util.testing as tm
-import pytest
+try:
+    import mock
+except ImportError:  # pragma: NO COVER
+    from unittest import mock
+
 import numpy
 from pandas import DataFrame
+import pandas.util.testing as tm
+import pkg_resources
+import pytest
 
 import pandas_gbq.exceptions
 from pandas_gbq import gbq
 
-try:
-    import mock
-except ImportError:  # pragma: NO COVER
-    from unittest import mock
 
 pytestmark = pytest.mark.filter_warnings(
     "ignore:credentials from Google Cloud SDK"
 )
+pandas_installed_version = pkg_resources.get_distribution(
+    "pandas"
+).parsed_version
 
 
 @pytest.fixture
@@ -90,7 +95,6 @@ def no_auth(monkeypatch):
         ("INTEGER", None),  # Can't handle NULL
         ("BOOLEAN", None),  # Can't handle NULL
         ("FLOAT", numpy.dtype(float)),
-        ("TIMESTAMP", "datetime64[ns, UTC]"),
         ("DATETIME", "datetime64[ns]"),
     ],
 )
@@ -104,6 +108,16 @@ def test_should_return_bigquery_correctly_typed(type_, expected):
         assert result == {"x": expected}
 
 
+def test_should_return_bigquery_correctly_typed_timestamp():
+    result = gbq._bqschema_to_nullsafe_dtypes(
+        [dict(name="x", type="TIMESTAMP", mode="NULLABLE")]
+    )
+    if pandas_installed_version < pkg_resources.parse_version("0.24.0"):
+        assert result == {"x": "datetime64[ns]"}
+    else:
+        assert result == {"x": "datetime64[ns, UTC]"}
+
+
 def test_to_gbq_should_fail_if_invalid_table_name_passed():
     with pytest.raises(gbq.NotFoundException):
         gbq.to_gbq(DataFrame([[1]]), "invalid_table_name", project_id="1234")
@@ -200,6 +214,10 @@ def test_to_gbq_with_verbose_old_pandas_no_warnings(recwarn, min_bq_version):
         assert len(recwarn) == 0
 
 
+@pytest.mark.skipif(
+    pandas_installed_version < pkg_resources.parse_version("0.24.0"),
+    reason="Requires pandas 0.24+",
+)
 def test_to_gbq_with_private_key_new_pandas_warns_deprecation(
     min_bq_version, monkeypatch
 ):
@@ -413,6 +431,10 @@ def test_read_gbq_with_verbose_old_pandas_no_warnings(recwarn, min_bq_version):
         assert len(recwarn) == 0
 
 
+@pytest.mark.skipif(
+    pandas_installed_version < pkg_resources.parse_version("0.24.0"),
+    reason="Requires pandas 0.24+",
+)
 def test_read_gbq_with_private_key_new_pandas_warns_deprecation(
     min_bq_version, monkeypatch
 ):