Types vs tests

Today, I saw a Twitter poll - "Poll: Imagine your team has to build a project with either types or tests. You can't have both.".

The results were:

Types - 50.9%

Tests - 49.1%

I was surprised by this.

If I can't add type declarations (type hints) or return types, I can still write tests to check what happens when different types are used.

I can also perform checks and throw errors or Exceptions if something isn't what I'd expect.

Here's the thing

I use types heavily, but I'd be more confident that my application would work if I had tests and that's the main objective when writing code for myself or clients and for my clients' customers.