Extract all ids from html
var extract = require('extract-html-id')
var assert = require('assert')
var html = `
<div id="foo">
<p id="bar">hello planet</p>
</div>
`
var expected = [ 'foo', 'bar']
assert.deepEqual(extract(html), expected, 'array was same')
Get an array of ids for the given string. Uses a regex so safe to run on non-html strings too. Returns the first ID per DOM element. Returns an empty array if no matches are found.