如何用构造函数进行单元测试

Question

I am trying to make a Unit Test out of a public Constructor.

Using Visual Studio 2012

How can I create a simple Unit Test out of this Constructor.

    public ScenarioSelectViewModel(IEventRecorderSvc service)
    {
        eventRecordingSvc = svc;

        OkCmd = new DelegateCommand<Window>(
            OkCmd Executed,
            OkCmd CanExecute);

        RefreshAvailableScenarioStepExecutionsCommand = new       DelegateCommand<object>(
            RefreshAvailableScenarioStepExecutionsCommandExecuted,
            RefreshAvailableScenarioStepExecutionsCommandCanExecute);

        if (RefreshAvailableScenarioStepExecutionsCommand.CanExecute(null))
        {
            RefreshAvailableScenarioStepExecutionsCommand.Execute(null);
        }
    }

Answer 1

Assuming OkCmd and RefreshAvailableScenarioStepExecutionsCommand are publicly exposed properties inyour class ScenarioSelectViewModel.

You are doing 2 things in the constructor which should be tested:

• Okmd and RefreshAvailableScenarioStepExecutionsCommand Initialization
• Execution of RefreshAvailableScenarioStepExecutionsCommand Command.

You can start asserting the objects that are created, then asserting their publicly exposed properties, ie OkCmd.Execute and OkCmd.CanExecute to whatever you are expecting them to be. Same goes with RefreshAvailableScenarioStepExecutionsCommand .

Then you can assert the execution of the RefreshAvailableScenarioStepExecutionsCommand command