如何编写 GRPC python unittest

Question

We are using grpc as the RPC protocol for all our internal system. Most of the system is written in Java.

In Java, we can use InprocessServerBuilder for unittest. However, I haven't find a similar class in Python.

Can any one provide a sample code for how to do GRPC unittest in python?

Answer 1

How serendipitous that you have asked this question today; our unit test framework just entered code review . So for the time being the way to test is to use the full production stack to connect your client-side and server-side code (or to violate the API and mock a lot of internal stuff) but hopefully in days to weeks the much better solution will be available to you.

Answer 2

I find pytest-grpc is easy to follow and get it works in few minutes.

src: https://pypi.org/project/pytest-grpc/

Answer 3

Some example code to get started:

proto

syntax = "proto3";

service Library {
    rpc Search (Request) returns (Response);
}

message Request {
    string id = 1;
}

message Response {
    string status = 1;
}

python unit test

#!/usr/bin/env python
# coding=utf-8

import unittest

from grpc import StatusCode
from grpc_testing import server_from_dictionary, strict_real_time
from proto import rpc_pb2

class TestCase(unittest.TestCase):

    def __init__(self, methodName) -> None:
        super().__init__(methodName)

        servicers = {
            rpc_pb2.DESCRIPTOR.services_by_name['Library']: LibraryServicer()
        }
        self.test_server = server_from_dictionary(
            servicers, strict_real_time())

    def test_search(self):
        request = rpc_pb2.Request(
            id=2,
        )
        method = self.test_server.invoke_unary_unary(
            method_descriptor=(rpc_pb2.DESCRIPTOR
                .services_by_name['Library']
                .methods_by_name['Search']),
            invocation_metadata={},
            request=request, timeout=1)

        response, metadata, code, details = method.termination()
        self.assertTrue(bool(response.status))
        self.assertEqual(code, StatusCode.OK)

if __name__ == '__main__':
    unittest.main()