For very simple programs, sure.
Type checkers do not verify behavior. Unit tests verify behavior
Type checkers do not verify behavior. Unit tests verify behavior
Types do verify behavior - e.g. this function always returns an Int, that function only returns a UserId, this other function doesn't do any I/O.
What you really want is to be able to state properties, e.g. "for all x/y, mul(x, 0) = 0, mul(x, 1) = x, mul(x, 2) = x + x, mul(x, y) = mul(y, x)", and so on. And working with these kinds of statements (via e.g. quickcheck or whatever) might generate tests, but feels a lot more like working with types. You're making proofs, not examples.