Created
March 16, 2016 23:06
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Context for tests
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# Inspired by http://stackoverflow.com/a/13875412 | |
class ContextMixin(object): | |
def setup_context(self): | |
self._ctxs = [] | |
for cls in reversed(self.__class__.mro()): | |
context_method = cls.__dict__.get('context') | |
if context_method: | |
ctx = context_method(self) | |
self._ctxs.append(ctx) | |
for ctx in self._ctxs: | |
try: | |
next(ctx) | |
except TypeError: | |
raise RuntimeError('{}.context() must yield'.format(cls.__name__)) | |
def teardown_context(self): | |
for ctx in reversed(self._ctxs): | |
for _ in ctx: | |
raise RuntimeError('{}.context() must not yield more than once'.format(cls.__name__)) | |
class A(ContextMixin): | |
def context(self): | |
print 'set up A' | |
yield | |
print 'tear down A' | |
class B(ContextMixin): | |
def context(self): | |
print 'set up B' | |
yield | |
print 'tear down B' | |
class C(object): | |
pass | |
class Test(C, B, A): | |
def context(self): | |
print 'set up test' | |
with open('/tmp/testfile', 'w') as f: | |
self.f = f | |
yield | |
print 'tear down test' | |
test = Test() | |
test.setup_context() | |
print 'run test here', test.f | |
test.teardown_context() | |
""" | |
Output: | |
set up A | |
set up B | |
set up test | |
run test here <open file '/tmp/testfile', mode 'w' at 0x1109d48a0> | |
tear down test | |
tear down B | |
tear down A | |
""" |
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