Attempt to set cookie inside server handle throws TypeError: immutable

[astev89]

Example code:

        event.cookies.set('test', JSON.stringify(new Date()), {
            path: '/',
            httpOnly: true,
            secure: process.env.NODE_ENV === 'production',
            sameSite: 'strict',
            maxAge: sessionData.exp,
        });

        const response = await resolve(event);
        return response;

I'm not sure if the header guard being set to immutable prior to event resolution inside handle is expected or not. Or even if anyone else has experienced this? Currently running next.480.

[teemingc]

I think you should create an issue for this. This should be clarified in the docs or removed/fixed if it unintended behaviour.

Previously, to set cookies in handle, you'd have to add it to response.headers after resolve(event).

[astev89]

Thank you for the reply and noted. Worth mentioning that using the previous method response.headers.append('Set-Cookie', ...) after event resolution is also throwing the same error for me. I'll work on getting a demo repo put together for this.