Standard HTTP header to ask for deduplicated data

[mxstbr]

Instead of recommending to use a query param, why don't we recommend using a custom HTTP header to request deduplicated data?

• inflate is a noop if the data wasn't deflated it doesn't matter whether the backend ends up sending deduplicated data or not
• Headers aren't visible in the URL which is neater
• Backend usage is the ~same

I imagine something like this:

const httpLink = new HttpLink({
  credentials: 'include',
  uri: '/api',
  headers: {
    'X-GraphQL-Deduplicate': true
  }
});

app.use('/graphql', graphqlExpress((request) => {
  return {
    formatResponse: (response) => {
      if (request.headers['X-GraphQL-Deduplicate'] && response.data && !response.data.__schema) {
        return deflate(response.data);
      }

      return response;
    }
  };
}));

[gajus]

The only reason I have suggested GET query parameter is because thats what I was using when debugging/ developing. However, I agree that this information is better communicated via a header.

I will update the documentation.

p.s. request.headers exposes get and has methods.

Thank you