Guest cart lost when logging in

[John-Ad]

Problem

If a user is not logged in and they add items to their cart, when they proceed to checkout, they are prompted to log in. Once logged in, the cart they had when they were not logged in is lost.

Expected outcome

The guest cart should be merged with the customer cart. Eg, if orderOptions.mergeStrategy in vendure-config.ts is UseGuestStrategy, the customer cart should be replaced with the guest cart.

Possible fix

In /apps/storefront/src/app/sign-in/actions.ts, the mutate call in loginAction does not make use of the guest auth token. Adding the token allows for the carts to be merged:

const result = await mutate(LoginMutation, {
        username,
        password,
    }, { useAuthToken: true });