fix(helpers): JSON+LD detects number pproperly

[kristianeaw]

lodash isEmpty considers numbers (and booleans) an empty value (https://lodash.com/docs/4.17.10#isEmpty), so it is not possible to scape numbers properly.

For example if you try to scrape prices with the following rules, and 'price' has a value (for example 25.5), but 'offers.price' and '0.offers.price' does not, it will loop though the remaining fields and you end up with no value.

price: [
    ({htmlDom: $, url}: type) => $jsonld('price')($, url),
    ({htmlDom: $, url}: type) => $jsonld('offers.price')($, url),
    ({htmlDom: $, url}: type) => $jsonld('0.offers.price')($, url),
]

Wasn't sure if I should file an issue or a PR, or if this behavior is intended for some reason, but would love to see a fix/workaround for this 😊

[Kikobeats]

Hey, thanks for that.

Can you tell me a JSON+LD structure for creating a unit test there?

Just to be sure the these fails under the current codebase and it passes green after the change 🙂

[Kikobeats]

This could be the test

describe('.$jsonld', function () {
    it('detect numbers', () => {
      const $ = cheerio.load(`
      <script type="application/ld+json">{ "offers": { "price": 119.99 }}</script>
      <script type="application/ld+json">{ "price": { "price": "" }}</script>
      `)
      should($jsonld('offers.price')($)).be.equal('119.99')
    })
  })

Let me add it and merge this PR; thanks for it 🙂

[kristianeaw]

Thanks so much for getting to this so quickly! 😄

[Kikobeats]

released at v5.21.9 🎉