需求及问题
在框架中，捕获并记录用例运行时的print输出信息是非常重要的。如下图。
image.png
在原始的unittest.TextTestResult中，这些输出信息是直接输出终端的，当然也将全部的运行结果输出到文本文件中。
如果需要分别捕获不同用例的输出信息，一般采用重定向系统输入流的方式来实现，如下图。
image.png
每个用例在开始执行前将系统标准输出流重定向到一个自定义的io.String()流中，这样用例中的print等信息就会输出到此流中。在用例结束时获取该流中的数据，并还原系统标准输出流。
这种模式，用例在执行期间需要独占系统输出流。在用例多线程并发时（多进程并发无此问题），使用同一系统输出流，便会导致不同用例的输出捕获混乱。如果对线程加锁则相当于串行，并发便没有意义。
解决思路
使用自定义的io流，分线程存储结果，用例运行时记录下其线程id，执行结束时重全部的io流中取出用例线程id对应的输出信息，如下图。
image.png
实现步骤
- 自定义io流按线程存储输出的信息
import io
import threading
class ThreadStringIO(io.StringIO):
"""按线程存取结果"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.values = defaultdict(str) # 按线程号存储
def write(self, text):
# log.info('线程输出', text)
thread_id = str(threading.current_thread().ident)
super().write(text)
self.values[thread_id] += text
def writelines(self, lines):
super().writelines(lines)
thread_id = str(threading.current_thread().ident)
text = ''.join(lines)
self.values[thread_id] += text
def getvalues(self):
"""返回线程结果字典"""
return self.values
- 重写父类_setupStdout中重定向的io流
def _setupStdout(self):
"""分线程存储"""
if self.buffer:
if self._stderr_buffer is None:
# self._stderr_buffer = io.StringIO()
# self._stdout_buffer = io.StringIO()
self._stderr_buffer = ThreadStringIO()
self._stdout_buffer = ThreadStringIO()
sys.stdout = self._stdout_buffer
sys.stderr = self._stderr_buffer
- 重写_restoreStdout方法并返回按线程存储的io流数据
def _restoreStdout(self):
"""重写父类的_restoreStdout方法"""
if self.buffer:
# if self._mirrorOutput:
# output = sys.stdout.getvalue()
# error = sys.stderr.getvalue()
outputs = self._stdout_buffer.getvalues()
errors = self._stderr_buffer.getvalues()
sys.stdout = self._original_stdout
sys.stdout = self._original_stderr
self._stdout_buffer.seek(0)
self._stdout_buffer.truncate()
self._stderr_buffer.seek(0)
self._stderr_buffer.truncate()
return outputs, errors
- 用例运行开始时记录运行的线程id
def startTest(self, test: unittest.case.TestCase):
"""单个用例执行开始"""
test.result = TestCaseResult(test)
self.testcase_results.append(test.result)
test.result.thread_id = str(threading.current_thread().ident) # 线程id
test.result.start_at = time.time()
self.testsRun += 1
# self._mirrorOutput = False
self._setupStdout()
- 用例运行结束时从_restoreStdout返回的流数据中按用例线程id取出捕获的输出
def stopTest(self, test: unittest.case.TestCase) -> None:
"""单个用例结束"""
test.result.end_at = time.time()
test.result.duration = test.result.end_at - test.result.start_at
outputs, errors = self._restoreStdout()
test_output = outputs.get(test.result.thread_id, '') + errors.get(test.result.thread_id, '')
test.result.output = test_output.strip()
...
完整代码
import inspect
import platform
import sys
import time
import traceback
import unittest
import io
from unittest.result import failfast
import re
import threading
from collections import defaultdict
from logz import log
log.format = '%(asctime)s %(threadName)s %(thread)d %(levelname)s %(message)s'
TAG_PARTTEN = 'tag:(\w+)'
LEVEL_PARTTEN = 'level:(\d+)'
def get_case_tags(case: unittest.TestCase) -> list:
"""从用例方法的docstring中匹配出指定格式的tags"""
case_tags = None
case_doc = case._testMethodDoc
if case_doc and 'tag' in case_doc:
pattern = re.compile(TAG_PARTTEN)
case_tags = re.findall(pattern, case_doc)
return case_tags
def get_case_level(case: unittest.TestCase):
"""从用例方法的docstring中匹配出指定格式的level"""
case_doc = case._testMethodDoc
case_level = None # todo 默认level
if case_doc:
pattern = re.compile(LEVEL_PARTTEN)
levels = re.findall(pattern, case_doc)
if levels:
case_level = levels[0]
try:
case_level = int(case_level)
except:
raise ValueError(f'用例中level设置：{case_level} 应为整数格式')
return case_level
class TestStatus(object):
SUCCESS = 'success'
FAIL = 'fail'
ERROR = 'error'
SKIPPED = 'skipped'
XFAIL = 'xfail'
XPASS = 'xpass'
def time_to_string(timestamp: float) -> str:
"""时间戳转时间字符串"""
time_array = time.localtime(timestamp)
time_str = time.strftime("%Y-%m-%d %H:%M:%S", time_array)
return time_str
def get_platform_info():
"""获取执行平台信息"""
return {
"platform": platform.platform(),
"system": platform.system(),
"python_version": platform.python_version(),
# "env": dict(os.environ), # 可能包含敏感信息
}
def inspect_code(test):
test_method = getattr(test.__class__, test._testMethodName)
try:
code = inspect.getsource(test_method)
except Exception as ex:
log.exception(ex)
code = ''
return code
class ThreadStringIO(io.StringIO):
"""按线程存取结果"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.values = defaultdict(str) # 按线程号存储
def write(self, text):
# log.info('线程输出', text)
thread_id = str(threading.current_thread().ident)
super().write(text)
self.values[thread_id] += text
def writelines(self, lines):
super().writelines(lines)
thread_id = str(threading.current_thread().ident)
text = ''.join(lines)
self.values[thread_id] += text
def getvalues(self):
"""返回线程结果字典"""
return self.values
class TestCaseResult(object):
"""用例测试结果"""
def __init__(self, test: unittest.case.TestCase, name=None):
self.test = test # 测试用例对象
self.name = name or test._testMethodName # 支持传入用例别名，unittest.TestCase自带属性方法
self.id = test.id() # 用例完整路径，unittest.TestCase自带方法
self.description = test.shortDescription() # 用例简要描述，unittest.TestCase自带方法
self.doc = test._testMethodDoc # 用例docstring，，unittest.TestCase自带属性方法
self.module_name = test.__module__ # 用例所在模块名
self.class_name = test.__class__.__name__ # 用例所在类名
self.class_id = f'{test.__module__}.{test.__class__.__name__}' # 用例所在类完整路径
self.class_doc = test.__class__.__doc__ # 用例所在类docstring描述
self.tags = get_case_tags(test) # 获取用例tags
self.level = get_case_level(test) # 获取用例level等级
self.code = inspect_code(test) # 获取用例源代码
# 用例执后更新的信息
self.start_at = None # 用例开始时间
self.end_at = None # 用例结束时间
self.duration = None # 用例执行持续时间
self.status = None # 用例测试状态
self.output = None # 用例内的print信息
self.exc_info = None # 用例异常信息
self.reason = None # 跳过,失败,出错原因
@property
def data(self): # 组合字典格式的用例结果数据
data = dict(
name=self.name,
id=self.test.id(),
description=self.description,
status=self.status,
tags=self.tags,
level=self.level,
time=dict(
start_at=self.start_at,
end_at=self.end_at,
duration=self.duration
),
class_name=self.class_name,
class_doc=self.class_doc,
module_name=self.module_name,
code=self.code,
output=self.output,
exc_info=self.exc_info,
reason=self.reason,
)
return data
class TestResult(unittest.TestResult):
"""测试结果,补充整个过程的运行时间"""
def __init__(self,
stream=None,
descriptions=None,
verbosity=None,
):
super().__init__(stream, descriptions, verbosity)
self.successes = []
self.testcase_results = [] # 执行的用例结果列表
self.verbosity = verbosity or 1
self.buffer = True
self.know_exceptions = None
self.name = None
self.start_at = None
self.end_at = None
self.duration = None
self.successes_count = 0
self.failures_count = 0
self.errors_count = 0
self.skipped_count = 0
self.expectedFailures_count = 0
self.unexpectedSuccesses_count = 0
self._stdout_buffers = dict() # 按线程存
self._stderr_buffers = dict() # 按线程存
self.threadId = str(threading.current_thread().ident)
@property
def summary(self):
"""组装结果概要, details分按运行顺序和按类组织两种结构"""
data = dict(
name=self.name,
success=self.wasSuccessful(),
stat=dict(
testsRun=self.testsRun,
successes=self.successes_count,
failures=self.failures_count,
errors=self.errors_count,
skipped=self.skipped_count,
expectedFailures=self.expectedFailures_count,
unexpectedSuccesses=self.unexpectedSuccesses_count,
),
time=dict(
start_at=self.start_at,
end_at=self.end_at,
duration=self.duration
),
platform=get_platform_info(), # 环境信息的最后状态
details=[testcase_result.data for testcase_result in self.testcase_results]
)
return data
def _setupStdout(self):
"""分线程存储"""
# rlock.acquire()
# if self._stdout_buffers.get(self.threadId) is None:
# self._stdout_buffers[self.threadId] = io.StringIO()
# self._stderr_buffers[self.threadId] = io.StringIO()
# sys.stdout = self._stdout_buffers[self.threadId]
# sys.stderr = self._stderr_buffers[self.threadId]
if self.buffer:
if self._stderr_buffer is None:
# self._stderr_buffer = io.StringIO()
# self._stdout_buffer = io.StringIO()
self._stderr_buffer = ThreadStringIO()
self._stdout_buffer = ThreadStringIO()
sys.stdout = self._stdout_buffer
sys.stderr = self._stderr_buffer
def _restoreStdout(self):
"""重写父类的_restoreStdout方法"""
if self.buffer:
# if self._mirrorOutput:
# output = sys.stdout.getvalue()
# error = sys.stderr.getvalue()
outputs = self._stdout_buffer.getvalues()
errors = self._stderr_buffer.getvalues()
sys.stdout = self._original_stdout
sys.stdout = self._original_stderr
self._stdout_buffer.seek(0)
self._stdout_buffer.truncate()
self._stderr_buffer.seek(0)
self._stderr_buffer.truncate()
return outputs, errors
def _get_exc_msg(self, err):
exctype, value, tb = err
exc_msg = str(value)
exc_full_path = f'{exctype.__module__}.{exctype.__name__}'
if self.know_exceptions and isinstance(self.know_exceptions, dict):
exc_msg = self.know_exceptions.get(exc_full_path, exc_msg)
return exc_msg
def _exc_info_to_string(self, err, test):
"""重写父类的转换异常方法, 去掉buffer的输出"""
exctype, value, tb = err
while tb and self._is_relevant_tb_level(tb):
tb = tb.tb_next
if exctype is test.failureException:
# Skip assert*() traceback levels
length = self._count_relevant_tb_levels(tb)
else:
length = None
tb_e = traceback.TracebackException(
exctype, value, tb, limit=length, capture_locals=self.tb_locals)
msgLines = list(tb_e.format())
return ''.join(msgLines)
def startTestRun(self):
"""整个执行开始"""
self.start_at = time.time()
if self.verbosity > 1:
log.info(f'===== 测试开始, 开始时间: {time_to_string(self.start_at)} =====')
def stopTestRun(self):
"""整个执行结束"""
self.end_at = time.time()
self.duration = self.end_at - self.start_at
self.success = self.wasSuccessful()
if self.verbosity > 1:
log.info(f'===== 测试结束, 持续时间: {self.duration}秒 =====')
# log.info(self.summary['stat'])
# log.info(self.summary['time'])
def startTest(self, test: unittest.case.TestCase):
"""单个用例执行开始"""
test.result = TestCaseResult(test)
self.testcase_results.append(test.result)
test.result.thread_id = str(threading.current_thread().ident) # 线程id
test.result.start_at = time.time()
self.testsRun += 1
# self._mirrorOutput = False
self._setupStdout()
if self.verbosity > 1:
log.info(f'执行用例: {test.result.name}: {test.result.description}, 开始时间: {time_to_string(test.result.start_at)}')
def stopTest(self, test: unittest.case.TestCase) -> None:
"""单个用例结束"""
test.result.end_at = time.time()
test.result.duration = test.result.end_at - test.result.start_at
outputs, errors = self._restoreStdout()
test_output = outputs.get(test.result.thread_id, '') + errors.get(test.result.thread_id, '')
test.result.output = test_output.strip()
if self.verbosity > 1:
log.info(f'结果: {test.result.status}, 持续时间: {test.result.duration}秒')
elif self.verbosity > 0:
log.info(f'{test.result.name} ... {test.result.status}')
if self.verbosity > 0:
if test.result.output:
log.info(f'{test.result.output.strip()}')
if test.result.exc_info:
log.exception(test.result.exc_info)
def addSuccess(self, test):
"""重写父类方法, 单个用例成功时在stopTest前调用"""
test.result.status = TestStatus.SUCCESS
self.successes.append(test)
self.successes_count += 1
# super().addSuccess(test)
@failfast
def addFailure(self, test, err):
"""重写父类方法, 用例失败时在stopTest前调用"""
test.result.status = TestStatus.FAIL
test.result.exc_info = self._exc_info_to_string(err, test)
test.result.reason = self._get_exc_msg(err)
self.failures_count += 1
# super().addFailure(test, err)
self.failures.append((test, self._exc_info_to_string(err, test)))
# self._mirrorOutput = True
@failfast
def addError(self, test, err):
"""重写父类方法, 用例异常时在stopTest前调用"""
test.result.status = TestStatus.ERROR
test.result.exc_info = self._exc_info_to_string(err, test)
test.result.reason = self._get_exc_msg(err)
self.errors_count += 1
# super().addError(test, err)
self.errors.append((test, self._exc_info_to_string(err, test)))
# self._mirrorOutput = True
def addSkip(self, test, reason):
"""重写父类方法, 用例跳过时在stopTest前调用"""
test.result.status = TestStatus.SKIPPED
test.result.reason = reason
self.skipped_count += 1
# super().addSkip(test, reason)
self.skipped.append((test, reason))
def addExpectedFailure(self, test, err):
"""重写父类方法, 用例期望失败时在stopTest前调用"""
test.result.status = TestStatus.XFAIL
test.result.exc_info = self._exc_info_to_string(err, test)
test.result.reason = self._get_exc_msg(err)
self.expectedFailures_count += 1
# super().addExpectedFailure(test, err)
self.expectedFailures.append(
(test, self._exc_info_to_string(err, test)))
@failfast
def addUnexpectedSuccess(self, test):
"""重写父类方法, 用例非期望成功时在stopTest前调用"""
test.result.status = TestStatus.XPASS
self.expectedFailures_count += 1
# super().addUnexpectedSuccess(test)
self.unexpectedSuccesses.append(test)