[conradk]

I have been made aware further down that I might have confused unit and integration tests a bit. Sorry about that. In Symfony code, the two co-exist and look somewhat similar. Maybe that's why I don't really differentiate them.

[bluGill]

To be honest I don't actually differentiate them either.

When my function under test calls sort() I don't fake that call out, so technically I just wrote an integration test. (In fact I work with one group that will inject a fake sort())

If I write a library foo which has sub-module bar which has class baz and fuzz, is the test for bar that tests both baz and fuzz a unit test of an integration test? Of course if you are a user of my library tests for foo are unit tests to you...

[szatkus]

I once spent an evening reading and watching wise people on the internet to find out where is difference between unit tests and integration tests. It's really fuzzy and depends on a source.

There's no agreement what is "unit". Few classes interacting with each other could still be a unit.

I didn't find any strict definition which would be useful in practice. I just write tests and guess they are mostly integration tests, some end-to-end tests and a few unit tests.