Why does TypeScript trigger an ESLint error when using `extend` on a template string?

I am looking to create a TrimStart type in the following way:

type TrimStart<T extends string> = T extends ` ${infer Rest}` ? TrimStart<Rest> : T;

type TT = TrimStart<'   Vue React Angular'>; // 'Vue React Angular'

However, I encountered the error message: Parsing error: Type expected.eslint

Answer №1

Don't overlook declaring the generic parameter T in your code.

type CapitalizeWords<T> = T extends ` ${infer Word}` ? CapitalizeWords<Word> : T;

type CW = CapitalizeWords<'JavaScript TypeScript Python'>
// type CW = "JavaScript TypeScript Python"

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