Nested `await` demo

demo.js

// Query builders are not actually promises, but have a `.then()` method which matches the promise interface.
// As soon as you `await` or `.then()` the builder, the query is executed, and a new promise is generated that will contain the result.
const getQueryBuilder = () => ({
  then: (resolve) =>
    resolve(
      new Promise((resolve) =>
        setTimeout(() => resolve(["query", "results"]), 1000),
      ),
    ),
})

// This method does nothing but wrap the query builder in a promise
const modifyQueryBuilder = async (queryBuilder) => {
  await new Promise((resolve) => setTimeout(resolve, 1000))
  return queryBuilder
}

// When we await the modification method, we also await the query's results
const execute = async () => {
  const queryBuilder = getQueryBuilder()
  const modifiedQueryBuilder = await modifyQueryBuilder(queryBuilder)

  // Prints ['query', 'results']
  console.log(modifiedQueryBuilder)
}

execute()