How to perform batch Create/Add mutation for a many-to-many relation in amplify app-sync?

[socialyadept]

I just finished to test the Many-To-Many Connections example and It worked for me. However, I still can't figure it out how to use only one mutation (and if it's even possible) to achieve the same result as the one given in the documentation. For example:

mutation CreateLinks {
    p1u1: createPostEditor(input: { id: "P1U1", postID: "P1", editorID: "U1" }) {
        id
    }   
    p1u2: createPostEditor(input: { id: "P1U2", postID: "P1", editorID: "U2" }) {
        id
    }
}

So far I was able to handle this with promise, but I'm not sure if this is the best approach (because it involves to execute as much mutations as there are users):

        const users = [{id: "U1", username: "user1"}, {id: "U2", username: "user2"}];
        const post = { id: "P1", title: "Post 1" };
        /*
        After creating two users and a post using the appropriate mutations
        Using the CreatePost join below to make user1 and user2 editor on Post 1
        */
        function graphqlCreatePostEditor(editorID) {
            return new Promise((resolve, reject) => {
              resolve(
                API.graphql(graphqlOperation(createPostEditor, {
                  input: {
                      postID: post.id,
                      editorID
                    }
                }))
              )
            })
          }
  
        let promises = users.map(user=> {
            return graphqlCreatePostEditor(user.id)
            .then(e => {
                console.log(e)
            return e;
            })
        });

        Promise.all(promises)
            .then(results => {
                console.log(results)
            })
            .catch(e => {
                console.error(e);
            })

Originally posted by @devnantes44 in aws-amplify/amplify-cli#91 (comment)

Anyone having a solution to this? I just want to create a mutation that can first create the post and add all the editors let's say they come from an array directly into the join table of PostEditor table. Any clue?