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@lmiller1990
Created January 29, 2024 10:58
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awaited.ts
type Awaited<T> = T extends null | undefined ? T : // special case for `null | undefined` when not in `--strictNullChecks` mode
T extends object & { then(onfulfilled: infer F, ...args: infer _): any; } ? // `await` only unwraps object types with a callable `then`. Non-object types are not unwrapped
F extends ((value: infer V, ...args: infer _) => any) ? // if the argument to `then` is callable, extracts the first argument
Awaited<V> : // recursively unwrap the value
never : // the argument to `then` was not callable
T; // non-object or non-thenable
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