Good article, but you forgot one more thing: Readability.

Given that there are zero comments in the code, you are giving the impression of "The code is the documentation" attitude which forces the programmer to infer via the function signatures only, which compromises clean-code and maintainability. It is important to explain what these functions and one-liners do, as a different set of eyes might not easily understand what it is.

If a candidate did this in a pair-programming session, I'm afraid that I would not accept this solution unless a reasonable amount of documentation in the function signatures like JSDoc is present.