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/*
** We support the GET, POST, HEAD, and OPTIONS methods from any origin, and accept the Content-Type header on requests.
** These headers must be present on all responses to all CORS requests.
** In practice, this means all responses to OPTIONS requests.
**
** Modified by Alejandro Akbal (VoidlessSeven7)
*/
/**
* Fetches the request content and returns it
* @param {*} request
*/
async function handleRequest(request) {
// Initialize url and query
const url = new URL(request.url);
const query = url.search.split('?q=')[1];
/*
* Rewrite request to point to API url. This also makes the request mutable
* so we can add the correct Origin header to make the API server think
* that this request isn't cross-site.
*/
request = new Request(query, request);
/*
* Set headers to make the endpoint think it's itself
*/
request.headers.set('Host', new URL(query).origin);
request.headers.set('Referer', new URL(query));
request.headers.set('Origin', new URL(query));
request.headers.set('Access-Control-Allow-Credentials', 'true');
request.headers.delete('X-Content-Type-Options');
// Fetch it
let response = await fetch(request);
// Recreate the response so we can modify the headers
response = new Response(response.body, response);
// Set CORS headers
response.headers.set('Access-Control-Allow-Origin', 'https://due.moe');
// Append to/Add Vary header so browser will cache response correctly
response.headers.append('Vary', 'Origin');
response.headers.set('Cache-Control', 'max-age=300');
// Return it
return response;
}
/**
* Makes sure that the necessary headers are present for this to be a valid pre-flight request
* @param {*} request
*/
async function handleOptions(request) {
/*
* Handle CORS pre-flight request.
* If you want to check the requested method + headers you can do that here.
*/
if (
request.headers.get('Origin') !== null &&
request.headers.get('Access-Control-Request-Method') !== null &&
request.headers.get('Access-Control-Request-Headers') !== null
) {
return new Response(null, {
headers: {
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Methods': 'GET, HEAD, POST, OPTIONS',
'Access-Control-Allow-Headers': '*',
},
});
/*
* Handle standard OPTIONS request.
* If you want to allow other HTTP Methods, you can do that here.
*/
} else {
return new Response(null, {
headers: {
Allow: 'GET, HEAD, POST, OPTIONS',
},
});
}
}
/*
** Event listener for fetching content (What starts everything)
*/
addEventListener('fetch', (event) => {
// Initialize
const request = event.request;
// Handle CORS preflight requests
switch (request.method) {
case 'OPTIONS':
event.respondWith(handleOptions(request));
break;
// Handle requests
case 'GET':
case 'HEAD':
case 'POST':
event.respondWith(handleRequest(request));
break;
// If no good option then return error
default:
event.respondWith(async () => {
return new Response(null, {
status: 405,
statusText: 'Method Not Allowed',
});
});
break;
}
});
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