How to measure the execution time of a promise?

Question

I\'m trying to write a function that measures the execution time of another function:

export class Profiler {
    public measureSyncFunc(fn: () => any): P         


        

Answer 1

Don't use setInterval to count milliseconds (It's inaccurate, lags, drifts and has a minimum interval of about 4ms). Just get two timestamps before and after the execution.

function measureASyncFunc(fn: () => Promise): Promise {
    const start = Date.now();
    return fn.catch(() => {}).then(() => {
        const end = Date.now();
        const elapsed = end-start;
        return elapsed;
    });
}

For higher accuracy, replace Date.now by performance.now.