[elyseum]

No need to ‘return’ when you throw an error, but your approach is valid IMO: if structure / readability is that important, refactor the switch to it’s own method with only if checks in it. Hard to make that simpler and more readable.

[notyourday]

If you don't have a 'return' there's nothing to say that some time later some junior developer would not modify throw to be something else or forget that throw does not return.

[dfee]

This will prevent the JR dev from making that mistake: https://eslint.org/docs/rules/no-fallthrough

[BiteCode_dev]

That's what tests are for.