Node measure execution time - return value from an async passed as parameter to another function

Question

I want to write a function to measure the performance of parts of code (other methods) that could return a value. This is what I came out at the moment:

const fn = async (): Promise<any> => {
    setTimeout(async (): Promise<any> => {
        return new Promise((resolve) => resolve('Hello World!'));
    }, 3000);
};

async measure(fn: () => Promise<any>): Promise<any> {
    const startTime = this.performance.now();
    const result = await functionToMeasure();
    const endTime = this.performance.now();

    const executionTime = endTime - startTime;
    console.log(`Executed in ${executionTime} ms`);

    return result;
}

const result = async measure(functionToMeasure); // result is undefined

The result is that functionToMeasure actually runs but it never returns something and at the moment I can use it only with void function.

I'd like to fix it if possible, or I can change completely if there's a better way to do it.

EDIT:

Actual code

const callback = async (): Promise<any> => {
    return await doSomethingAndReturn();
};
const searchResults: string[] = await measure(callback);

Do I've to wrap doSomethingAndReturn in an async Promise?

Answer 1

You need to wrap the setTimeout call in a promise and then resolve the result, so it should look something like this:

const {performance} = require('perf_hooks');

async function executeAndMeasure(fn) {
    const startTime = performance.now();
    const result = await fn();
    const endTime = performance.now();

    const executionTime = endTime - startTime;
    console.log(`Executed in ${executionTime} ms`);

    return result;
}

function someFnThatReturnsAPromise() {
    return new Promise(resolve => {
        setTimeout(() => {
            resolve("Hello World");
        }, 3000);
    })
}

async function someAsyncFunction() {
    return 123;
}

(async () => {
    let result = await executeAndMeasure(someFnThatReturnsAPromise);
    console.log(`result was ${result}`);
    result = await executeAndMeasure(someAsyncFunction);
    console.log(`result was ${result}`);
})();