> Testing in the same module has the advantage of testing non exported parts of > your code.
You can test "private" APIs if you `include` the file to test instead of `import` ing it. That said, I think it's good to also have tests where the file to test is `import` ed. Otherwise you could run into the situation that the tests succeed but production code fails because you forgot to make some necessary API public. This is likely not a problem for applications where you eventually import and use the module, but it may be a problem for libraries.
