Authorization via decorators type-graphql in combination with express-graphql throws 500 error on authorization failure

[Jackywathy]

Hi, I'm running into an issue when using type-graphql in conjunction with express-graphql. When I try to access an endpoint while not authorized, the server returns the appropriate error message, but with a 500 error code. An example response below:

{"errors":[{"message":"Access denied! You need to be authorized to perform this action!","locations":[{"line":2,"column":3}],"path":["userDetails"]}],"data":null}

I believe the reason for this is because the data attribute is set to null, which is technically against the graphql spec. express-graphql expects data to be either not equal to null or not present, and thus throws a 500 error. Is there any workaround to this problem? Thanks.

Below is my authorization decorator code and the resolver in question, which I have applied.

const userAuthChecker: AuthChecker<Context> = async ({
    context,
}: ResolverData<Context>): Promise<boolean> => {
    // ... some conditions which return true
    return false;
};

class UserResolver {
    @Authorized()
    @Query(() => UserResponse)
    async userDetails(@Ctx() { res, conn }: Context): Promise<UserResponse> {
       // ... some more conditions
       return new UserResponse();
    }
}