Dependent Types: Level Up Your Types

Dependent types make types into first-class language constructs and ensure type safety depending on values and not only types. They help to get rid of all unit tests because dependent types require a proof that a function behaves as expected. This proof needs to be written by the developer himself and verifies that the function works correctly for all possible inputs. So a type, in the end, is a proof for the compiler and no unit tests are needed. Type checking may become undecidable since these types can depend on any value or expression.
This paper gives an overview what problem dependent types solve, kinding, dependent type theory and then a fairly big part about the differences to other systems. It then shows some current ongoing research and finally explains why dependent types may play a bigger role in the far future.