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Aggregate requests

Send two GET request to two urls and aggregates the responses into one response.

/**
* someHost is set up to return JSON responses
* Replace url1 and url2 with the hosts you wish to send requests to
* @param {string} url the URL to send the request to
*/
const someHost = "https://examples.cloudflareworkers.com/demos"
const url1 = someHost + "/requests/json"
const url2 = someHost + "/requests/json"
const type = "application/json;charset=UTF-8"
/**
* gatherResponse awaits and returns a response body as a string.
* Use await gatherResponse(..) in an async function to get the response body
* @param {Response} response
*/
async function gatherResponse(response) {
const { headers } = response
const contentType = headers.get("content-type") || ""
if (contentType.includes("application/json")) {
return JSON.stringify(await response.json())
}
else if (contentType.includes("application/text")) {
return response.text()
}
else if (contentType.includes("text/html")) {
return response.text()
}
else {
return response.text()
}
}
async function handleRequest() {
const init = {
headers: {
"content-type": type,
},
}
const responses = await Promise.all([fetch(url1, init), fetch(url2, init)])
const results = await Promise.all([
gatherResponse(responses[0]),
gatherResponse(responses[1]),
])
return new Response(results.join(), init)
}
addEventListener("fetch", event => {
return event.respondWith(handleRequest())
})