Struggling to return a list of items from cache from a different query root

[adam-thomas-privitar]

I feel like my use case might be more obvious than I think, but I'm really struggling to wrap my head around the docs. This is my last of throw of the dice. Any help much appreciated.

What im trying to do is to make it so a query, lets call it Query B, returns the known items which have previously been fetched into my graphcache by Query A. I believe since I accessed these deep items differently in Query A and Query B, I need to hint with my own resolvers. However, in the docs, I cant see a way in which I can fetch all records of a given type and return them where I need.

Query A

This query is made before query B, and basically its the "tags" im interested in. I'll comment in the query the typename for clarity.

query QueryA {
    exampleItem(id: '12345') {
        __typename    // ExampleItem
         id
         name
         tags {
               __typename   // Tag
              id
              value
         }
    } 
}

Query B

This is a query which now fetches a list of tags. I'd like it to returns the Tags which have already been retrieved as part of the above entity.

query QueryB {
  tags {
    __typename    // TagConnection
    edges {
       __typename    // TagEdge
      node {
        __typename  // Tag
        id
        value
      }
    }
  }
}

So essentially, I now need query B to get all the Tags already populated into the denormalised cache by QueryA, but wrapped in this outer structure (nodes/edges).

This is where my struggles begin. I have proven to myself I can return what I want for the tags query root by adding something dumb like this:

  resolvers: {
    Query: {
      tags: (parent, args, cache) => {
        return {
          __typename: 'TagConnection',
          edges: [
            {
              __typename: 'TagEdge',
              node: {
                __typename: 'Tag',
                id: 'im an example',
                value: 'lol',
              },
            },
          ],
        }
      },
    },
  },

But how can I use cache to return an array of all known Tags in the cache, so I can return them all here?

As youve probably realised, I'm going to use relay style pagination. Im yet to load the graphcache extension for that -- and I dont know if that affects the answer to my problem.

[adam-thomas-privitar]

I think the issue is the same as these:

#1843
#1251

In which case, I'm going to hack around it by iterating the private cache manually for now.