unittest 基础之 —— TestResult

testresult就是存储测试结果的，不过通过何种方式调用run函数，最终到Testcase中的run方法时

必须传一个result（如果为None则自己实例化一个TestResult对象)。这个result就是TestResult

对象或者是其子类的对象，我们每次执行的结果都会调用其addFailure，addSuccess，addSkip….

等方法将执行结果保存到TestResult实例属性中。我们还是来看看TestCase的run方法：

def run(self, result=None):
        orig_result = result
        if result is None:#如果没有传入result对象自己实例化一个TestResult对象
            result = self.defaultTestResult()
            startTestRun = getattr(result, 'startTestRun', None)
            if startTestRun is not None:
                startTestRun()

        self._resultForDoCleanups = result
        result.startTest(self)

        testMethod = getattr(self, self._testMethodName)
        if (getattr(self.__class__, "__unittest_skip__", False) or
            getattr(testMethod, "__unittest_skip__", False)):
            # If the class or method was skipped.
            try:
                skip_why = (getattr(self.__class__, '__unittest_skip_why__', '')
                            or getattr(testMethod, '__unittest_skip_why__', ''))
                self._addSkip(result, skip_why)#调用addSkip
            finally:
                result.stopTest(self)
            return
        try:
            success = False
            try:
                self.setUp()
            except SkipTest as e:
                self._addSkip(result, str(e))
            except KeyboardInterrupt:
                raise
            except:
                result.addError(self, sys.exc_info())#调用addError
            else:
                try:
                    testMethod()
                except KeyboardInterrupt:
                    raise
                except self.failureException:
                    result.addFailure(self, sys.exc_info())#调用addFailure
                except _ExpectedFailure as e:
                    addExpectedFailure = getattr(result, 'addExpectedFailure', None)
                    if addExpectedFailure is not None:
                        addExpectedFailure(self, e.exc_info)#调用addExpectedFailure
                    else:
                        warnings.warn("TestResult has no addExpectedFailure method, reporting as passes",
                                      RuntimeWarning)
                        result.addSuccess(self)#调用addSuccess
                except _UnexpectedSuccess:
                    addUnexpectedSuccess = getattr(result, 'addUnexpectedSuccess', None)
                    if addUnexpectedSuccess is not None:
                        addUnexpectedSuccess(self)
                    else:
                        warnings.warn("TestResult has no addUnexpectedSuccess method, reporting as failures",
                                      RuntimeWarning)
                        result.addFailure(self, sys.exc_info())
                except SkipTest as e:
                    self._addSkip(result, str(e))
                except:
                    result.addError(self, sys.exc_info())
                else:
                    success = True

                try:
                    self.tearDown()
                except KeyboardInterrupt:
                    raise
                except:
                    result.addError(self, sys.exc_info())
                    success = False

            cleanUpSuccess = self.doCleanups()
            success = success and cleanUpSuccess
            if success:
                result.addSuccess(self)
        finally:
            result.stopTest(self)
            if orig_result is None:
                stopTestRun = getattr(result, 'stopTestRun', None)
                if stopTestRun is not None:
                    stopTestRun()