使用pytest的Python单元测试覆盖率

Question

我是pytest的新手，我想添加以下3种方法来覆盖单元测试，而不需要实际使用真正的mongodb实例，而是模拟它。可以尝试使用真实的数据库实例，但不建议使用。请求提供如何模拟mongodb客户端并获取文档的示例

import os
import logging
import urllib.parse
from dotenv import load_dotenv
from pymongo import MongoClient
from logger import *
load_dotenv()

def getMongoConnection():
userName = urllib.parse.quote_plus(os.getenv("USER_NAME"))
password = urllib.parse.quote_plus(os.getenv("PASSWORD"))
hostName1_port = os.getenv("HOST_NAME1")
hostName2_port = os.getenv("HOST_NAME2")
hostName3_port = os.getenv("HOST_NAME3")
authSourceDatabase = os.getenv("AUTH_SOURCE_DATABASE")
replicaSet = os.getenv("REPLICA_SET")
connectTimeoutMS = "1000"
socketTimeoutMS = "30000"
maxPoolSize = "100"
try:
client = MongoClient('mongodb://'+userName+':'+password+'@'+hostName1_port+','+hostName2_port+','+hostName3_port+'/'+authSourceDatabase+'?ssl=true&replicaSet='+replicaSet +
'&authSource='+authSourceDatabase+'&retryWrites=true&w=majority&connectTimeoutMS='+connectTimeoutMS+'&socketTimeoutMS='+socketTimeoutMS+'&maxPoolSize='+maxPoolSize)
return client
except Exception as e:
logging.error("Error while connecting to mongoDB.")
return False

def connectToDBCollection(client, databaseName, collectionName):
db = client[databaseName]
collection = db[collectionName]
return collection

def getDoc(bucketName, databaseName, collectionName):
try:
client = getMongoConnection()
if client != False:
collection = connectToDBCollection(
client, databaseName, collectionName)
return collection.find_one({'bucket': bucketName})
except Exception as e:
logging.error("An exception occurred while fetching doc, error is ", e)

编辑：(尝试使用以下代码，能够覆盖大多数情况，但看到错误(

def test_mongo():
db_conn = mongomock.MongoClient()
assert isinstance(getMongoConnection(), MongoClient)

def test_connect_mongo():
return connectToDBCollection(mongomock.MongoClient(), "sampleDB", "sampleCollection")

//trying to cover exception block for getMongoConnection()
def test_exception():
with pytest.raises(Exception) as excinfo:
getMongoConnection()
assert str(excinfo.value) == False

def test_getDoc():
collection = mongomock.MongoClient().db.collection
stored_obj = collection.find_one({'_id': 1})
assert stored_obj == getDoc("bucket", "db", "collection")

def test_createDoc():
collection = mongomock.MongoClient().db.collection
stored_obj = collection.insert_one({'_id': 1})
assert stored_obj == createDoc("bucket", "db", "collection")

def test_updateDoc():
collection = mongomock.MongoClient().db.collection
stored_obj = collection.replace_one({'_id': 1}, {'_id': 2})
assert stored_obj == updateDoc(
{'_id': 1}, {'$set': {'_id': 2}}, "db", "collection")

错误：test_exception-失败：未提升<类"异常">test_createDoc-TypeError：并非所有参数都在字符串格式化过程中转换断言错误：assert<0x7fc0e835a400>==处的pymongo.results.UpdateResult对象<0x7fc0e8211900>处的pymongo.results.UpdateResult对象；

Answer 1

看起来MongoClient是一个带有databaseName和collectionName的嵌套dict，或者是用密钥访问器实现的。

你可以先用模拟客户

import unittest
mocked_collection = unittest.mock.MagicMock()
# mock the find_one method
mocked_collection.find_one.return_value = {'data': 'collection_find_one_result'}
mocked_client = unittest.mock.patch('pymongo.MongoClient').start()
mocked_client.return_value = {
'databaseName': {'collectionname': mocked_collection}
}

Answer 2

也许可以尝试像MongoMock这样的专门的mocking库？

特别是，使用@mongomock.patch的最后一个示例看起来可能与您的代码相关。