removing __typename field from urql query result before mutation

Question

when querying data from a GraphQL Server, urql adds a _typename field to track the cache:

{
    __typename  "Book"
    name  "test"
    description "the book"
    id  "hPl39w4rzc2HZxkfHDyj"
    auther "John Doe"
}

I want to update this object and save it back to the database. when the useMutation function is called __typename is passed also and since it is not part of the server schema it results in an error:

Field \"__typename\" is not defined by type

I know I can do something like this before calling useMutation:

delete input.__typename;

but I want to know if there is a better way of handling globally in urql? For instance, in apollo-client you can use ApolloLink to remove __typename from all the variables before updating

Answer 1

const result = {
    __typename:  "Book",
    name:  "test",
    description: "the book",
    id:  "hPl39w4rzc2HZxkfHDyj",
    auther: "John Doe"
}

const {__typename, ...rest} = result;

console.log(rest)

It's probably best to keep that marker on the objects in the graphql client because it helps the cache do its thing. So you can instead remove it as needed -- here you can update "rest" and use that to call your update mutation.