Confirming from a JUnit test that a FileReader was closed properly

Question

I'm writing some Java code that uses a FileReader to load data from a few input files. I'm using TDD pretty heavily, and I'd like to add some tests that ensure that I'm cleaning up properly by calling close() on the reader when I'm done with it. Unfortunately, I can't come up with a good way to test for this. Anyone have any insights? Edited to add: I know I can test explicitly for the close call using mock objects, but I'd like to avoid it if possible, partly because I find they lead to somewhat brittler code, and partly because I'm curious whether it's possible to write code that can recognize the effects of not closing a file.) JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

I think the way to do this is to inject the FileReader, or a Factory that creates the FileReader, into your class. Then in your unit test you can inject a mock version of the FileReader and check that the proper method on it has been called. You might want to look at JMock to create the mock FileReader and set up the expectation for the close method call.