Rebased upon parameter pre-parsing

Author: Zhen

neo4j/bolt/connection.py

@@ -239,12 +239,7 @@ def append(self, signature, fields=(), response=None):
             log_info("C: INIT (%r, {...})", fields[0])
         else:
             raise ValueError("Unknown message signature")
-        try:
-            self.packer.pack_struct(signature, fields)
-        except ValueError as e:
-            # We failed to pack this message, therefore we close this connection to avoid sending corrupted data
-            self.close()
-            raise e
+        self.packer.pack_struct(signature, fields)
         self.output_buffer.chunk()
         self.output_buffer.chunk()
         self.responses.append(response)

neo4j/v1/api.py

@@ -614,8 +614,7 @@ def rollback(self):
     def close(self):
         """ Close this transaction, triggering either a COMMIT or a ROLLBACK.
         """
-        conn_closed = self.session._connection.closed()
-        if not self.closed() and not conn_closed:
+        if not self.closed():
             try:
                 self.sync()
             except CypherError:

test/integration/test_session.py

@@ -435,14 +435,14 @@ def test_should_sync_after_rollback(self):
 
     def test_errors_on_write_transaction(self):
         session = self.driver.session()
-        with self.assertRaises(ValueError):
+        with self.assertRaises(TypeError):
             session.write_transaction(lambda tx, uuid : tx.run("CREATE (a:Thing {uuid:$uuid})", uuid=uuid), uuid4())
         session.close()
 
     def test_errors_on_run_transaction(self):
         session = self.driver.session()
         tx = session.begin_transaction()
-        with self.assertRaises(ValueError):
+        with self.assertRaises(TypeError):
             tx.run("CREATE (a:Thing {uuid:$uuid})", uuid=uuid4())
         tx.rollback()
         session.close()