TS Interface doesn't force functions signature on implementers

This is interesting. The TypeScript team are quite clever chaps and they decided to do this deliberately.

The idea is that if your function can operate correctly without being passed an argument, it can safely ignore the argument and satisfy the interface. This means you can substitute your implementation without having to update all of the calling code.

The interface ensures that the argument is passed in all cases where you are consuming the interface - so you get type checking on the callers and it actually doesn't matter that your concrete class doesn't need any parameters.

Interface Function Parameter Not Enforced