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2637. Promise Time Limit
Description
Given an asyncronous function fn
and a time t
in milliseconds, return a new time limited version of the input function.
A time limited function is a function that is identical to the original unless it takes longer than t
milliseconds to fullfill. In that case, it will reject with "Time Limit Exceeded"
. Note that it should reject with a string, not an Error
.
Example 1:
Input: fn = async (n) => { await new Promise(res => setTimeout(res, 100)); return n * n; } inputs = [5] t = 50 Output: {"rejected":"Time Limit Exceeded","time":50} Explanation: The provided function is set to resolve after 100ms. However, the time limit is set to 50ms. It rejects at t=50ms because the time limit was reached.
Example 2:
Input: fn = async (n) => { await new Promise(res => setTimeout(res, 100)); return n * n; } inputs = [5] t = 150 Output: {"resolved":25,"time":100} Explanation: The function resolved 5 * 5 = 25 at t=100ms. The time limit is never reached.
Example 3:
Input: fn = async (a, b) => { await new Promise(res => setTimeout(res, 120)); return a + b; } inputs = [5,10] t = 150 Output: {"resolved":15,"time":120} Explanation: The function resolved 5 + 10 = 15 at t=120ms. The time limit is never reached.
Example 4:
Input: fn = async () => { throw "Error"; } inputs = [] t = 1000 Output: {"rejected":"Error","time":0} Explanation: The function immediately throws an error.
Constraints:
0 <= inputs.length <= 10
0 <= t <= 1000
fn returns a promise
Solutions
-
type Fn = (...params: any[]) => Promise<any>; function timeLimit(fn: Fn, t: number): Fn { return async function (...args) { return Promise.race([ fn(...args), new Promise((_, reject) => setTimeout(() => reject('Time Limit Exceeded'), t), ), ]); }; } /** * const limited = timeLimit((t) => new Promise(res => setTimeout(res, t)), 100); * limited(150).catch(console.log) // "Time Limit Exceeded" at t=100ms */