responseReducer returns entire payload when leaf is not truthy

[Dmitry Ivanov]

Package

graphql-hooks

Environment

• graphql-hooks version: latest

Description

In this code responseReducer applies only if it returns a truthy value:

data:
                // enrich data with responseReducer if defined
                (typeof options.responseReducer === 'function' &&
                  options.responseReducer(data, response)) ||
                data,

Consider a use case when we query a single leaf:

query something {
  haslevels {
    and {
      we {
        only {
          need {
            this
          }
        }
      }
    }
  }
}

My responseReducer will look like this:

responseReducer: (data) => data?.haslevels?.and?.we?.only?.need?.this;

Let's say false or '' is a valid value in this use case. We won't receive it, we'll get the entire data object back.

How to reproduce

Create a responseReducer that points to a single field in the response. Make that field being cast to false.

Suggested solution (optional)

Do not check for the function value to be truthy?