[mangodrunk]

I don’t think it’s worth doing that, and comparing it to scientific experiments doesn’t really apply.

You can do all that without mocks as well.

Making the tests run faster at the expense of better tests seems counterproductive.

Now you should think of reasons why you should not isolate.

[danparsonson]

> I don’t think it’s worth doing that

OK; it's your choice to do what you think is right.

> and comparing it to scientific experiments doesn’t really apply.

Why not? I think it's a fairly apt comparison; you have a theory ("this piece of code does the following things"), and write tests to prove it.

> You can do all that without mocks as well.

OK, but mocks make it easier and cleaner - so why wouldn't I do that?

> Making the tests run faster at the expense of better tests seems counterproductive.

Smaller, more focused, cleaner tests are better in my opinion; speed is a beneficial side effect.

> Now you should think of reasons why you should not isolate.

Why? That's your argument - it's not on me to prove it for you. If you can give me some good reason why mocking out the interfaces you are not testing is a bad idea, and some better alternative, then we can have a discussion about it.

[mangodrunk]

I don’t want to take too much of a tangent, but in scientific studies, you are trying to understand some phenomena, and isolating variables can help with very complex things. A test is typically not that complex. Another example is the use of animals in testing medicine, it can help but it obviously would be much better to test directly on humans but we don’t for good reason.

Your position is reasonable and I do think isolation can be beneficial, but I still wouldn’t use mocking to do it.

>Smaller, more focused, cleaner tests are better in my opinion.

Cleaner is subjective. I can write “small” and “focused” functional tests that are also quick to run.

I am of the opinion that functional tests provide more value. They are testing more of the actual code than an approximation, which in turn gives a better indicator that it works. Functional tests are less likely to change unless the input/output changes.

Now let’s say you mock something in your function. Let’s say you make a change to that but the input and output are the exact same. Now you have to update your test.