Python单元测试：模拟补丁

Question

我正试图为Cassandra编写单元测试，但无法使其工作。代码如下：

CassandraLoggingModel.py公司名称：

import uuid

from cassandra.cqlengine import columns
from datetime import datetime
from cassandra.cqlengine.models import Model

class CassandraRunLog(Model):

    pipeline_id = columns.Text(partition_key=True, max_length=180)
    task_id = columns.Text(partition_key=True, max_length=180)
    execution_date = columns.DateTime(partition_key=True)
    created_at = columns.DateTime(primary_key=True, default=datetime.now())
    host = columns.Text(max_length=1000)
    run_as_unixname = columns.Text(max_length=1000)
    logger = columns.Text(max_length=128)
    level = columns.Text(max_length=16)
    trace = columns.Text(max_length=10000)
    msg = columns.Text(max_length=64000)

在CassandraLogging.py在

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在测试.py在

import datetime
import logging
import mock
from CassandraLogging import CassandraHandler

@mock.patch('CassandraLoggingModel.CassandraRunLog')
def test_formatting(MockClassRunLog):

    run_log = MockClassRunLog.return_value

    # construct our logging handler
    handler = CassandraHandler('name')

    # Log an unformated message.
    record = logging.LogRecord(name='pytest',
                               level=logging.INFO,
                               pathname='something',
                               lineno=0,
                               msg='something',
                               args=(),
                               exc_info=None,
                               func='test_formatting')
    handler.emit(record)

    # we should have a record added to the DB
    run_log.save.assert_called_once_with()

我尝试在python中添加一个日志处理程序，它将日志消息存储到cassandra数据库中。我正在测试是否调用了模型的save方法。save方法在Cassandra模型中实现，CassandraRunLog继承自该模型。在

当我使用命令运行测试时：

py.test test.py

我得到以下错误：

E           AssertionError: Expected to be called once. Called 0 times.

有人能帮忙吗？在

Answer 1

没关系。我想出来了。测试无法连接到数据库，因此每次都将控制权传递给except块。在