feat: add support for NUMERIC type

google/cloud/spanner_v1/_helpers.py

@@ -15,6 +15,7 @@
 """Helper functions for Cloud Spanner."""
 
 import datetime
+import decimal
 import math
 
 import six
@@ -127,6 +128,8 @@ def _make_value_pb(value):
         return Value(string_value=value)
     if isinstance(value, ListValue):
         return Value(list_value=value)
+    if isinstance(value, decimal.Decimal):
+        return Value(string_value=str(value))
     raise ValueError("Unknown type: %s" % (value,))
 
 
@@ -201,6 +204,8 @@ def _parse_value_pb(value_pb, field_type):
             _parse_value_pb(item_pb, field_type.struct_type.fields[i].type)
             for (i, item_pb) in enumerate(value_pb.list_value.values)
         ]
+    elif field_type.code == type_pb2.NUMERIC:
+        result = decimal.Decimal(value_pb.string_value)
     else:
         raise ValueError("Unknown type: %s" % (field_type,))
     return result

google/cloud/spanner_v1/param_types.py

@@ -25,6 +25,7 @@
 FLOAT64 = type_pb2.Type(code=type_pb2.FLOAT64)
 DATE = type_pb2.Type(code=type_pb2.DATE)
 TIMESTAMP = type_pb2.Type(code=type_pb2.TIMESTAMP)
+NUMERIC = type_pb2.Type(code=type_pb2.NUMERIC)
 
 
 def Array(element_type):  # pylint: disable=invalid-name

tests/unit/test__helpers.py

@@ -208,6 +208,15 @@ def test_w_datetime(self):
         self.assertIsInstance(value_pb, Value)
         self.assertEqual(value_pb.string_value, datetime_helpers.to_rfc3339(now))
 
+    def test_w_numeric(self):
+        import decimal
+        from google.protobuf.struct_pb2 import Value
+
+        value = decimal.Decimal("9999999999999999999999999999.999999999")
+        value_pb = self._callFUT(value)
+        self.assertIsInstance(value_pb, Value)
+        self.assertEqual(value_pb.string_value, str(value))
+
     def test_w_unknown_type(self):
         with self.assertRaises(ValueError):
             self._callFUT(object())
@@ -431,6 +440,17 @@ def test_w_struct(self):
 
         self.assertEqual(self._callFUT(value_pb, field_type), VALUES)
 
+    def test_w_numeric(self):
+        import decimal
+        from google.protobuf.struct_pb2 import Value
+        from google.cloud.spanner_v1.proto.type_pb2 import Type, NUMERIC
+
+        VALUE = decimal.Decimal("99999999999999999999999999999.999999999")
+        field_type = Type(code=NUMERIC)
+        value_pb = Value(string_value=str(VALUE))
+
+        self.assertEqual(self._callFUT(value_pb, field_type), VALUE)
+
     def test_w_unknown_type(self):
         from google.protobuf.struct_pb2 import Value
         from google.cloud.spanner_v1.proto.type_pb2 import Type