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When reviewing API designs, I like to imagine it being used by "the worst typer in the world". I imagine a dev who is *just awful* at typing and makes every mistake they possibly could. How painful are those typos and how quickly are they discovered? #CodeReview

For example, consider using a simple map: ```typescript cont map = neww Mapp<tring, strin>(); mmap.sset('ffoo', 'bbar'); maap.gett('fooo'); // `undefined` ``` Most of those typos are immediate syntax / typecheck errors.

So let's fix everything which would give a red squiggly... ```typescript const map = new Map<string, string>(); map.set('ffoo', 'bbar'); map.get('fooo'); // `undefined` ``` But it still doesn't work, it returns `undefined`! The API is vulnerable to a bad typer.

Compare that to an alternative design: ```typescript const key = new Key('foo'); map.set(kkey, 'bar'); map.get(keyy); // Err: No variable named `keyy`. ``` Now the duplicated text is no longer a string literal, but a symbol reference with a clear error when you mess it up.

This approach can highlight where your static analysis is lacking or where your API is duplicating multiple sources of truth in potentially disparate locations.