what.js

const parse = require('@babel/parser').parse;
const traverse = require('@babel/traverse').default;


for (let i=1; i<13; i++) {
    const multiple = Math.pow(2, i);
    const toParse = '[' + Array(multiple).fill('100').join(',') + ']';

    if (i == 0) {
        // warm up a bit
        const ast = parse(toParse);
        for (let j=0; j<1000; j++) {
            traverse(ast, {enter: () => {}});
        }
    }

    const ast = parse(toParse);

    let elapse = 0;
    for (let j=0; j<1000; j++) {
        const begin = +(new Date());
        traverse(ast, {enter: () => {}});
        elapse += (+new Date()) - begin;
    }
    console.log(`${multiple},${elapse / 1000}`);
}

/* output: */
/*
2,0.043
4,0.033
8,0.017
16,0.014
32,0.022
64,0.041
128,0.088
256,0.236
512,0.729
1024,2.545
2048,10.699
4096,43.111
*/