In this test case:

let (i, j) = twoSum [2, 2, 3] 4 in (min i j, max i j) `shouldBe` (0, 1)

Answer could be (0, 0), but it is wrong

Thanks! Update fixed tests, move last test case to root edge cases.

Thanks, rewrite part of description and add tests.

Can you show me the proper way to hide os.path module funtions?

I wrote it:

File path is never empty and can starts with slash (means that it already starts from root).

Then file path starts with / workdir ignored, cause file path is absolute path.

Multiple slashes are allowed, you can test it with readlink -m, example readlink -m "/../foo//////bar///hello/////world/.."