example.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Demo</title>
  </head>
  <body>
    <pre>
      npx serve .
      open http://localhost:5000/example
    </pre>
    <pre id="log"></pre>
    <script type="module">
      import createFetch, {query, bodify, headers} from './dist/index.js'

      const myFetch = createFetch(fetch, [
        query(),
        bodify(),
        headers({'x-requested-with': 'fetch'}),
      ])
      myFetch('/', {
        method: 'POST',
        query: {foo: 'bar'},
        body: new URLSearchParams({lang: '中文'}),
      }).then(r => {
        console.info(r)
        log.textContent = [...r.headers].join('\n')
      })
    </script>
  </body>
</html>