I’m trying to fetch a remote URL with a worker, modify headers and cache a new response. When I’m caching the response, I get the error:
Body has already been used. It can only be used once. Use tee() first if you need to read it twice.
I’m unsure how to use tee() in my case. Can you direct me, please?
async fetch(request, env, ctx) {
// Get url param from a query string
const urlParsed = new URL(request.url)
const remoteUrl = urlParsed.searchParams.get('url')
// Convert to a GET to be able to cache
const cacheKey = new Request(remoteUrl, {
headers: request.headers,
method: 'GET',
})
const cache = caches.default
const cacheResponse = await cache.match(cacheKey)
if (cacheResponse) return cacheResponse
// fetch remote file
const response = await fetch(remoteUrl)
// Clone the response so that it's no longer immutable
const newResponse = new Response(response.body, response)
// Add a custom header with a value
newResponse.headers.append('Access-Control-Allow-Origin', '*')
newResponse.headers.append('Access-Control-Allow-Methods', 'GET')
newResponse.headers.append(
'Access-Control-Allow-Headers',
'Origin, Content-Type, Accept, X-Requested-With, Authorization'
)
newResponse.headers.append('cache-control', 'max-age=86400')
// Error occurs here
await cache.put(cacheKey, newResponse)
return newResponse
},