如何模拟googleapiclient.discovery.build

Question

我试图模拟API调用的结果，以计算引擎来列出am。但不幸的是不能嘲笑一个精确的函数。

我尝试过使用补丁和模拟方法来模拟特定的调用，但仍未成功。

code.py文件如下所示

import googleapiclient.discovery
import logging

class Service:
    def __init__(self, project, event):
        self.project_id = project
        self.compute = googleapiclient.discovery.build('compute', 'v1',
                                                       cache_discovery=False)
        self.event = event
        self.zones = self._validate_event()

    def _validate_event(self):
        if "jsonPayload" not in self.event:
            zones = self.compute.zones().list(
                project=self.project_id).execute()['items']

        else:
            zones = self.compute.zones().get(project=self.project_id,
                                             zone=self.event["jsonPayload"]
                                             ["resource"]["zone"]).execute()

        logging.debug(f"Identified Zones are {zones}")
        return [zone["name"] for zone in zones]

我的测试文件如下所示

# in-built
from unittest import TestCase
from unittest.mock import patch

# custom
import code


class TestServiceModule(TestCase):
    def setUp(self):
        self.project_id = "sample-project-id"

    @patch('code.googleapiclient.discovery')
    def test__validate_event_with_empty_inputs(self, mock_discovery):
        mock_discovery.build.zones.list.execute.return_value = {"items": [
            {
                "name": "eu-west-1"
            }
        ]}

        obj = code.Service(event={}, project=self.project_id)

        print(obj.zones)

在上面的测试用例中，我期望在打印obj.zones时将"eu-west-1“作为值。

Answer 1

您没有正确地模拟googleapiclient.discovery.build方法。以下是单元测试解决方案：

例如。

code.py

import googleapiclient.discovery
import logging


class Service:
    def __init__(self, project, event):
        self.project_id = project
        self.compute = googleapiclient.discovery.build('compute', 'v1', cache_discovery=False)
        self.event = event
        self.zones = self._validate_event()

    def _validate_event(self):
        if "jsonPayload" not in self.event:
            zones = self.compute.zones().list(project=self.project_id).execute()['items']
        else:
            zones = self.compute.zones().get(project=self.project_id,
                                             zone=self.event["jsonPayload"]["resource"]["zone"]).execute()

        logging.debug(f"Identified Zones are {zones}")
        return [zone["name"] for zone in zones]

test_code.py

from unittest import TestCase, main
from unittest.mock import patch
import code


class TestService(TestCase):
    def setUp(self):
        self.project_id = "sample-project-id"

    @patch('code.googleapiclient.discovery')
    def test__validate_event_with_empty_inputs(self, mock_discovery):
        # Arrange
        mock_discovery.build.return_value.zones.return_value.list.return_value.execute.return_value = {
            "items": [{"name": "eu-west-1"}]}

        # Act
        obj = code.Service(event={}, project=self.project_id)

        # Assert
        mock_discovery.build.assert_called_once_with('compute', 'v1', cache_discovery=False)
        mock_discovery.build.return_value.zones.assert_called_once()
        mock_discovery.build.return_value.zones.return_value.list.assert_called_once_with(project='sample-project-id')
        mock_discovery.build.return_value.zones.return_value.list.return_value.execute.assert_called_once()
        self.assertEqual(obj.zones, ["eu-west-1"])


if __name__ == '__main__':
    main()

包含覆盖率报告的单元测试结果：

.
----------------------------------------------------------------------
Ran 1 test in 0.002s

OK
Name                                      Stmts   Miss  Cover   Missing
-----------------------------------------------------------------------
src/stackoverflow/56794377/code.py           14      1    93%   16
src/stackoverflow/56794377/test_code.py      16      0   100%
-----------------------------------------------------------------------
TOTAL                                        30      1    97%

版本：

• google-api-python-client==1.12.3
• Python 3.7.5