Langr Software Solutions | The Compulsive Coder, Episode 7: Please AAA

Q. What behavior does the following JUnit test describe? (In other words, what’s an appropriate name for the test?)

            MockInitialContext mic = MockInitialContextFactory.getContext();
            mic.map.put(ClassicConstants.JNDI_CONTEXT_NAME, "tata");
    
            LoggerFactory.getLogger(ContextDetachingSCLTest.class);
    
            ContextJNDISelector selector = (ContextJNDISelector) ContextSelectorStaticBinder.getSingleton().getContextSelector();
            Context context = selector.getLoggerContext();
            assertEquals("tata", context.getName());
            System.out.println(selector.getContextNames());
            assertEquals(2, selector.getCount());

Maybe it helps, just a bit, if I tell you that the test name is testCreateContext.

Why must I spend time reading through each line of a test like this to understand what it’s really trying to prove?

The test designer might have made the central point of the test obvious, by visually chunking the test into its Arrange-Act-Assert (AAA) parts:

            MockInitialContext mic = MockInitialContextFactory.getContext();
            mic.map.put(ClassicConstants.JNDI_CONTEXT_NAME, "tata");
            LoggerFactory.getLogger(ContextDetachingSCLTest.class);
            ContextJNDISelector selector = (ContextJNDISelector) ContextSelectorStaticBinder.getSingleton().getContextSelector();
    
            Context context = selector.getLoggerContext();
    
            assertEquals("tata", context.getName());
            System.out.println(selector.getContextNames());
            assertEquals(2, selector.getCount());

Well, I think that’s right at least, given what we know.

(Yes, the word “test” in the name duplicates the requisite @Test annotation. And yes, there are other problems with the test, e.g. printing anything to the console. But it’s excruciatingly simple to first ensure the structure of a test is clear.)

Standards are only that if they are constantly adhered to.

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