> Consider the article's birthdayGreeting example. Author is happy that static typing catcges the birthdayGreeting("John", "20") bug because "20" is not a numbe

> Consider the article's birthdayGreeting example. Author is happy that static typing catcges the birthdayGreeting("John", "20") bug because "20" is not a number. But birthdayGreeting(" ", 123) is not caught (" " is not a name) and neither is birthdayGreeting("Anna," -12335). birthdayGreeting("Anna" 4.5), though, is caught, which arguably is wrong since 4.5 is an age. Author here. I think your examples illustrate my point rather than provide a counter example. I mentioned later in the post that we validate when creating the type (from e.g. user input) so we know that the `Name` type is always valid (and " ") is not a name. So the type ensures that we have a valid name. So this will definitely be caught in our codebase. As for birthdayGreeting("Anna" 4.5) and birthdayGreeting("Anna," -12335), number means a float in JS so it actually would be valid, though admittedly I had full integers in mind when writing this. Another example of where stricter typing than what TS providers (which Rust does!) would have helped better define the invariant. So in short: the problem in the code there was that I was trying to show a simple example, which means I didn't define all the types as strictly as I normally would have, and it surfaced more bugs that would have been caught with types.