我想将元数据添加到我为使用 Python 的 unittest 框架而编写的 TestCase 中的各个测试。元数据（实际上是一个字符串）需要通过测试过程并输出到 XML 文件。
除了保留在测试中之外，unittest 和我的测试代码都不会使用这些数据。 （我有一个稍后会运行的程序，打开 XML 文件，然后查找元数据/字符串）。
我以前使用过 NUnit，它允许使用 C# 属性来执行此操作。具体来说，你可以把它放在一个类之上：
[Property("SmartArrayAOD", -3)]
然后在 XML 输出中找到它。
是否可以在 Python 的 unittest 中将元数据附加到测试中？
【问题讨论】：
标签： python nunit python-unittest
如果您只想在每次单元测试后将内容写入 XML 文件，只需将 tearDown 方法添加到您的测试类（例如，如果您有 , give it a）。
class MyTest(unittest.TestCase):
def tearDown(self):
dump_xml_however_you_do()
def test_whatever(self):
pass
如果您想要一种从所有测试中收集和跟踪元数据并在最后返回的通用方法，请尝试在测试类的 __init__() 中创建一个 astropy 表，并在 tearDown() 期间向其中添加行，然后提取一个从 unittest 引用您的测试类的初始化实例，如下所示：
unittest.TestCase 的可重用子类，这样我们就不必重复处理表（将所有示例代码放在同一个文件中或复制导入）
"""
Demonstration of adding and retrieving meta data from python unittest tests
"""
import sys
import warnings
import unittest
import copy
import time
import astropy
import astropy.table
if sys.version_info < (3, 0):
from StringIO import StringIO
else:
from io import StringIO
class DemoTest(unittest.TestCase):
"""
Demonstrates setup of an astropy table in __init__, adding data to the table in tearDown
"""
def __init__(self, *args, **kwargs):
super(DemoTest, self).__init__(*args, **kwargs)
# Storing results in a list made it convenient to aggregate them later
self.results_tables = [astropy.table.Table(
names=('Name', 'Result', 'Time', 'Notes'),
dtype=('S50', 'S30', 'f8', 'S50'),
)]
self.results_tables[0]['Time'].unit = 'ms'
self.results_tables[0]['Time'].format = '0.3e'
self.test_timing_t0 = 0
self.test_timing_t1 = 0
def setUp(self):
self.test_timing_t0 = time.time()
def tearDown(self):
test_name = '.'.join(self.id().split('.')[-2:])
self.test_timing_t1 = time.time()
dt = self.test_timing_t1 - self.test_timing_t0
# Check for errors/failures in order to get state & description. https://stackoverflow.com/a/39606065/6605826
if hasattr(self, '_outcome'): # Python 3.4+
result = self.defaultTestResult() # these 2 methods have no side effects
self._feedErrorsToResult(result, self._outcome.errors)
problem = result.errors or result.failures
state = not problem
if result.errors:
exc_note = result.errors[0][1].split('\n')[-2]
elif result.failures:
exc_note = result.failures[0][1].split('\n')[-2]
else:
exc_note = ''
else: # Python 3.2 - 3.3 or 3.0 - 3.1 and 2.7
# result = getattr(self, '_outcomeForDoCleanups', self._resultForDoCleanups) # DOESN'T WORK RELIABLY
# This is probably only good for python 2.x, meaning python 3.0, 3.1, 3.2, 3.3 are not supported.
exc_type, exc_value, exc_traceback = sys.exc_info()
state = exc_type is None
exc_note = '' if exc_value is None else '{}: {}'.format(exc_type.__name__, exc_value)
# Add a row to the results table
self.results_tables[0].add_row()
self.results_tables[0][-1]['Time'] = dt*1000 # Convert to ms
self.results_tables[0][-1]['Result'] = 'pass' if state else 'FAIL'
with warnings.catch_warnings():
warnings.filterwarnings('ignore', category=astropy.table.StringTruncateWarning)
self.results_tables[0][-1]['Name'] = test_name
self.results_tables[0][-1]['Notes'] = exc_note
def manage_tests(tests):
"""
Function for running tests and extracting meta data
:param tests: list of classes sub-classed from DemoTest
:return: (TextTestResult, Table, string)
result returned by unittest
astropy table
string: formatted version of the table
"""
table_sorting_columns = ['Result', 'Time']
# Build test suite
suite_list = []
for test in tests:
suite_list.append(unittest.TestLoader().loadTestsFromTestCase(test))
combo_suite = unittest.TestSuite(suite_list)
# Run tests
results = [unittest.TextTestRunner(verbosity=1, stream=StringIO(), failfast=False).run(combo_suite)]
# Catch test classes
suite_tests = []
for suite in suite_list:
suite_tests += suite._tests
# Collect results tables
results_tables = []
for suite_test in suite_tests:
if getattr(suite_test, 'results_tables', [None])[0] is not None:
results_tables += copy.copy(suite_test.results_tables)
# Process tables, if any
if len(results_tables):
a = []
while (len(a) == 0) and len(results_tables):
a = results_tables.pop(0) # Skip empty tables, if any
results_table = a
for rt in results_tables:
if len(rt):
with warnings.catch_warnings():
warnings.filterwarnings('ignore', category=DeprecationWarning)
results_table = astropy.table.join(results_table, rt, join_type='outer')
try:
results_table = results_table.group_by(table_sorting_columns)
except Exception:
print('Error sorting test results table. Columns may not be in the preferred order.')
column_names = list(results_table.columns.keys())
alignments = ['<' if cn == 'Notes' else '>' for cn in column_names]
if len(results_table):
rtf = '\n'.join(results_table.pformat(align=alignments, max_width=-1))
exp_res = sum([result.testsRun - len(result.skipped) for result in results])
if len(results_table) != exp_res:
print('ERROR forming results table. Expected {} results, but table length is {}.'.format(
exp_res, len(results_table),
))
else:
rtf = None
else:
results_table = rtf = None
return results, results_table, rtf
class FunTest1(DemoTest):
@staticmethod
def test_pass_1():
pass
@staticmethod
def test_fail_1():
assert False, 'Meant to fail for demo 1'
class FunTest2(DemoTest):
@staticmethod
def test_pass_2():
pass
@staticmethod
def test_fail_2():
assert False, 'Meant to fail for demo 2'
res, tab, form = manage_tests([FunTest1, FunTest2])
print(form)
print('')
for r in res:
print(r)
for error in r.errors:
print(error[0])
print(error[1])
$ python unittest_metadata.py
Name Result Time Notes
ms
-------------------- ------ --------- ----------------------------------------
FunTest2.test_fail_2 FAIL 5.412e-02 AssertionError: Meant to fail for demo 2
FunTest1.test_fail_1 FAIL 1.118e-01 AssertionError: Meant to fail for demo 1
FunTest2.test_pass_2 pass 6.199e-03
FunTest1.test_pass_1 pass 6.914e-03
<unittest.runner.TextTestResult run=4 errors=0 failures=2>
应该适用于 python 2.7 或 3.7。您可以将所需的任何列添加到表中。您可以在setUp、tearDown 甚至在测试期间将参数和内容添加到表中。
此解决方案访问unittest.suite.TestSuite 的受保护属性_tests，可能会产生意外结果。这个特定的实现在 python2.7 和 python3.7 中按我的预期工作，但是套件的构建和询问方式的细微变化很容易导致奇怪的事情发生。不过，我想不出另一种方法来提取对 unittest 使用的类实例的引用。
【讨论】：