(Medium) - Decouple Side-Effects

TestOnlyTheHttpServerDataSource.js

QUnit.test('Query the posts title given some HTML server response', (assert) => {
  const getRequest = (url) => {
    return Promise.resolve(`
      <section>
        <h1 class="post-title">How to bake a cake</h1>
      </section>
    `);
  };
  const httpServerDataSource = HttpServerDataSource(getRequest);
  return httpServerDataSource.findPostsTitle().then((postsTitle) => {
    assert.deepEqual(postsTitle, ['How to bake a cake']);
  });
});