test: skip null/numeric related tests on emulator (#94)

Author: Ilya Gurov

README.md

@@ -204,6 +204,19 @@ with engine.begin() as connection:
 ```
 Connectionless way of use is also deprecated since SQLAlchemy 2.0 and soon will be removed (see in [SQLAlchemy docs](https://docs.sqlalchemy.org/en/14/core/connections.html#connectionless-execution-implicit-execution)).
 
+Running tests
+------------
+Spanner dialect includes a compliance, migration and unit test suite. To run the tests the `nox` package commands can be used:
+```
+# Run the whole suite
+$ nox
+
+# Run a particular test session
+$ nox -s migration_test
+```
+**Running tests on Spanner emulator**  
+The dialect test suite can be runned on [Spanner emulator](https://cloud.google.com/spanner/docs/emulator). Several tests, relating to `NULL` values of data types, are skipped when executed on emulator.
+
 Contributing
 ------------
 

test/test_suite.py

@@ -14,9 +14,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import decimal
 import operator
+import os
 import pytest
-import decimal
 import pytz
 from unittest import mock
 
@@ -329,7 +330,17 @@ class DateTest(DateFixtureTest, _DateTest):
     and maintain DRY concept just inherit the class to run tests successfully.
     """
 
-    pass
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null_bound_comparison(self):
+        super().test_null_bound_comparison()
+
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null(self):
+        super().test_null()
 
 
 class DateTimeMicrosecondsTest(_DateTimeMicrosecondsTest, DateTest):
@@ -349,6 +360,18 @@ def test_round_trip(self):
         eq_(row[0].rfc3339(), compare)
         assert isinstance(row[0], DatetimeWithNanoseconds)
 
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null_bound_comparison(self):
+        super().test_null_bound_comparison()
+
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null(self):
+        super().test_null()
+
 
 class DateTimeTest(_DateTimeTest, DateTimeMicrosecondsTest):
     """
@@ -359,7 +382,17 @@ class DateTimeTest(_DateTimeTest, DateTimeMicrosecondsTest):
     tests successfully.
     """
 
-    pass
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null_bound_comparison(self):
+        super().test_null_bound_comparison()
+
+    @pytest.mark.skipif(
+        bool(os.environ.get("SPANNER_EMULATOR_HOST")), reason="Skipped on emulator"
+    )
+    def test_null(self):
+        super().test_null()
 
 
 @pytest.mark.skip("Spanner doesn't support Time data type.")