import rclpy

from rclpy.node import Node

from sample_interfaces.srv import AddTwoStrings

import random

unittest

import unittest

import pytest

class AddTwoStringTestClass(unittest.Testcase):

def setUp(self):
    rcply.init(self):
    self.node_name = "node_" + str(random.randint(100,10000))
    print(self.node_name)
    self.node = Node(self.node_name)
    self.client = self.node.create_client(AddTwoStrings, "add_two_strings")

def tearDown(self):
    self.node.destiny_client(self.client)
    self.node.destory_node()
    rclpy.shutdown()

def test_a_call_service(self):
    print("Starting test A")
    request = AddTwoStrings.Request()
    request.str1 = "Some String"
    request.str2 = "Second String"
    self.future = self.client.call_async(request)
    while rclpy.ok():
        print('inside the loop')
        rclpy.spin_one(self.node)
        if self.client.wait_for_service(timeout_sec = 1.0):
            print('waiting for service')
            #rclpy.spin_once(self.node)
            continue
        print(self.client.call(request))
        if self.future.done():
            try:
                response = self.future.result()
            except Exception as e:
                print('error arrived')
                assert 1==0
                break
            else:
                print("Result received:", response.sum)
                break