cli-perf

It's an utility you can use to measure performance of some of your js functions.

Example

Assume you have file called concatVariants.js.

``javascript
const arr = [1, 2, 3];
const arr2 = [3, 4, 5];

module.exports = {
spread() {
return [...arr, ...arr2];
},
method() {
return arr.concat(arr2);
},
iteratorsPush() {
const res = [];
for (const x of arr) {
res.push(x);
}
for (const x of arr2) {
res.push(x);
}
},
forLoop() {
const res = Array(arr.length + arr2.length);
for (let i = 0; i < arr.length; i++) {
res[i] = arr[i];
}
for (let j = 0; j < arr2.length; j++) {
res[j + arr.length] = arr2[j];
}
return res;
},
};
`

And you want to findout which of the functions are the fastest.

You can run

`
npx cli-perf ./concatVariants.js
`

And it will show you benchmark measurements:

`
spread x 23,610,583 ops/sec ±1.94% (76 runs sampled)
method x 7,474,967 ops/sec ±2.73% (76 runs sampled)
iteratorsPush x 29,162,670 ops/sec ±2.46% (79 runs sampled)
forLoop x 77,835,824 ops/sec ±2.52% (79 runs sampled)
Fastest is forLoop
``