Function passthrough

public/mockServiceWorker.js:194–217

()

  const requestClone = request.clone()

  function passthrough() {
    // Cast the request headers to a new Headers instance
    // so the headers can be manipulated with.
    const headers = new Headers(requestClone.headers)

    // Remove the "accept" header value that marked this request as passthrough.
    // This prevents request alteration and also keeps it compliant with the
    // user-defined CORS policies.
    const acceptHeader = headers.get('accept')
    if (acceptHeader) {
      const values = acceptHeader.split(',').map((value) => value.trim())
      const filteredValues = values.filter(
        (value) => value !== 'msw/passthrough',
      )

      if (filteredValues.length > 0) {
        headers.set('accept', filteredValues.join(', '))
      } else {
        headers.delete('accept')
      }
    }

    return fetch(requestClone, { headers })
  }

  // Bypass mocking when the client is not active.
  if (!client) {