Fastest possible way to see if an element exists

[peterbe]

I'm sorry if this isn't a feature request or bug but I'm hunting for a way to use cheerio in the fastest possible way and my use case is simple. I just want to find out if an element exists. I don't need the element or know how many there are.

What I'm currently doing is something like this:

const $ = cheerio.load(htmlString)
cssselectors.forEach(selector => {
  if ($(selector).length) {
    console.log('It exists!')
  } else {
    console.log('Does not exist')
  }
}

In my use case I have hundreds or thousands of CSS selectors and I just want to find out, for each one, if there exists an element at all.

[fb55]

First thing that comes to mind is to use css-select directly (cheerio uses css-select as its selector engine). Something like this:

const {selectOne} = require('css-select')

const $ = cheerio.load('<document>')
const doesElementExist = !!selectOne('.someSelector', $.root().get(), $._options)

This way, each search terminates as soon as an element was found.

[fb55]

Another option would be to use

$.root().filter(`:scope:has(${mySelector})`)