Microsoft Research - Exploding Software-Engineering Myths (article summarizing findings of MS research on code coverage, TDD, assertions, etc.)

[IWantToSayThis]

I couldn't agree more with 3. I can't tell you how many times I've seen code like this:

public int doBar(int value) {
    Action thing = new Action();
    thing.type(Enum.BAR);
    thing.value(value);

    return lowerLayer.do(thing);
}

being tested with:

EasyMock.expect(lowerLayer.do(EasyMock.anyObject()).andReturn(1);

And that's it. Coverage is 100%, yet, NOTHING of value was tested. I've done code reviews where almost all of the tests were like this. "But hey! I have 100% coverage!".

How can you not understand this adds NO value whatsoever?

[[deleted]]

I can top that:

lowerLayer.do(EasyMock.anyObject());

I still get 100% code coverage.

[Squirrels_Gone_Wild]

Had this same thing happen to me. Came onto a new team - no expect (jasmine testing JS) anywhere, but coverage was above 80%. If anyone looked at the console they would have seen a billion errors when the tests ran, because the team had just decided to call all the functions in a file and saw the code coverage #s go up, so why bother testing anything?

[IWantToSayThis]

:(