Spanner: Fix database not found error, Closes googleapis#4071

Author: chemelnucfin

spanner/google/cloud/spanner_v1/database.py

@@ -18,6 +18,7 @@
 import threading
 
 import google.auth.credentials
+from google.api_core import exceptions
 from google.gax.errors import GaxError
 from google.gax.grpc import exc_to_code
 from google.cloud.spanner_v1.gapic.spanner_client import SpannerClient
@@ -208,14 +209,8 @@ def create(self):
                 options=options,
             )
         except GaxError as exc:
-            if exc_to_code(exc.cause) == StatusCode.ALREADY_EXISTS:
-                raise Conflict(self.name)
-            elif exc_to_code(exc.cause) == StatusCode.NOT_FOUND:
-                raise NotFound('Instance not found: {name}'.format(
-                    name=self._instance.name,
-                ))
-            raise
-
+            exception = exceptions.from_grpc_error(exc.cause)
+            raise exception
         return future
 
     def exists(self):

spanner/tests/system/test_system.py

@@ -36,6 +36,7 @@
 
 from google.cloud._helpers import UTC
 from google.cloud.exceptions import GrpcRendezvous
+from google.cloud.exceptions import NotFound
 from google.cloud.spanner_v1._helpers import TimestampWithNanoseconds
 from google.cloud.spanner import Client
 from google.cloud.spanner import KeyRange
@@ -282,6 +283,35 @@ def test_create_database(self):
             for database in Config.INSTANCE.list_databases()]
         self.assertIn(temp_db_id, database_ids)
 
+    def test_table_not_found(self):
+        temp_db_id = 'temp_db' + unique_resource_id('_')
+
+        table_name1 = 'MyTable'
+        table_name2 = 'NotMyTable'
+        self.assertNotEqual(table_name1, table_name2)
+
+        create_table = (
+            'CREATE TABLE {} (\n'
+            '    Id      STRING(36) NOT NULL,\n'
+            '    Field1  STRING(36) NOT NULL\n'
+            ') PRIMARY KEY (Id)')
+        create_table = create_table.format(table_name1)
+        create_index = 'CREATE INDEX IDX ON {} (Field1)'.format(table_name2)
+
+        temp_db = Config.INSTANCE.database(
+            temp_db_id,
+            ddl_statements=[
+                create_table,
+                create_index,
+            ],
+        )
+        with self.assertRaisesRegexp(NotFound,
+                                     '404 Table not found: '
+                                     + table_name2):
+            temp_db.create()
+            
+
+
     def test_update_database_ddl(self):
         pool = BurstyPool()
         temp_db_id = 'temp_db' + unique_resource_id('_')