browserfetcher.ex

def fetch(request, client_options) do
  # Start new browser session, with some extra parameters
  {:ok, session} =
    Wallaby.start_session(
      capabilities: %{
        javascriptEnabled: true,
        chromeOptions: %{args: ["--headless"]}
      }
    )

  # Visit the requested URL and fetch the page body 
  body =
    Wallaby.Browser.visit(session, request.url)
    |> Wallaby.Browser.page_source()

  url = Wallaby.Browser.current_url(session)
  
  # Don't forget to release resource, so you don't end up with millions of opened
  # browser windows
  :ok = Wallaby.end_session(session)
  
  # Finally return a structure which looks like a HTTPoison response
  {:ok, %HTTPoison.Response{status_code: 200, body: body, request_url: url}}
end