Storefront API now supports cart attributes with blank keys or values

The GraphQL Storefront API now supports setting cart attributes with either blank keys or values. This change applies to all API versions. This matches the behavior of the AJAX API, which allows for setting blank keys and attributes.


This is a companion discussion topic for the original entry at https://shopify.dev/changelog/storefront-api-now-supports-cart-attributes-with-blank-keys-or-values