How to design the following resolver for GraphQL server?

Question

I am using react-apollo on meteor with mysql and sequelize, I am still a beginner in JS. Lets assume I have the following resolver function on my apollo-server:

Answer 1

You should think more about the design and what each of those queries should do. Those queries should not mutate the database or the global state.

The best thing you can do is to simply define a new type that includes total and filtered, like what you did as NumberOfPosts in your first try, and also the list of posts.

So, your schema would be like:

type Post {
  id: Int
  date: Float
  text: String
}

type PostList {
  total: Int
  filtered: Int
  posts: [Post]
}

type Query {
  posts(
    id: Ind,
    offset: Int,
    limit: Int,
    filter: String): PostList
}

schema {
  query: Query
}

And you resolve posts like:

posts(_, args) {
  return Post.findAndCountAll({ where: args }).then(result => {
    return {
      total: 1000,
      filtered: result.count,
      posts: result.rows
    }
  })
}

Notice how I just put 1000 for the total number. You can not get the total number of rows with findAndCountAll. If you that, need you can run two different queries in parallel and use Promise.all to wait for them to be resolved.

posts(_, args) {
  return Promise.all([
    Post.count(),
    Post.findAndCountAll({ where: args })
  ]).then(data => {
    return {
      total: data[0],
      filtered: data[1].count,
      posts: data[1].rows
    }
  })
}

The above code also could benefit from ES6's destructuring:

posts(_, args) {
  return Promise.all([
    Post.count(),
    Post.findAndCountAll({ where: args })
  ]).then(([totalCount, filteredData]) => {
    return {
      total: totalCount,
      filtered: filteredData.count,
      posts: filteredData.rows
    }
  })
}

Now you can run:

query {
  posts(filter:"example") {
    total
    filtered
    posts {
      id
      date
      text
    }
  }
}

and get:

{
  "data": {
    "posts": {
      "total": 1000,
      "filtered": 21,
      "posts": [
        {
          "id": 4,
          "date": 5105626122,
          "text": "jzybiwutudi"
        },
        ...
      ]
    }
  }
}