This repo is a minimal reproduction of the issue where Azure Static Webapps strips out cookies that are set.

It's probably related to this issue: Azure/static-web-apps#760

To run locally: pnpm install and then pnpm dev

I've set this up to deploy to Azure SWA and you can see the difference between requests made to the local devserver and Azure SWA:

Notice that in production, the set-cookie header is not included even though the arr-disable-session-affinity header is correctly passed through. Both are set in the same file. You can see in src/hooks.server.ts:

export const handle: Handle = async ({ event, resolve }) => {
	event.setHeaders({ 'Arr-Disable-Session-Affinity': 'true' });
	event.cookies.set('testcookie', 'testcookie', {
		path: '/',
		maxAge: 31536000000,
		sameSite: "lax",
		httpOnly: false,
	});
	return await resolve(event);
};