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Discussion on: Lets Build Web Components! Part 3: Vanilla Components

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Benny Powers 🇮🇱🇨🇦 Author

if your goal is to test that the shadow root renders the way you expect, I suggest using the open-wc package semantic-dom-diff, which is built-in to open-wc's testing setup, like so:

import { expect, fixture } from `@open-wc/testing`;

describe('skyscanner flight search', function() {
  it('should render the correct Shadow DOM', async function() {
    const el = await fixture(`<skyscanner-flight-search></skyscanner-flight-search>`);
    await window.customElements.whenDefined('skyscanner-flight-search')
      <!-- this dom string will be semantically compared to the real dom -->
      <!-- comments will be stripped out -->
      <!-- and you'll get a helpful diff as otuput if you use open-wc's testing setup -->
      <div id="firstDiv"></div>
      <input id="inputSessionKey"/>