Nested (optional) input types

[Willianvdv]

Given I have a users connection that accepts an input type that accepts a where argument, this where input type has a couple of optional arguments. With GraphQL, you can query like so:

query {
  usersCalledLee: users(where: { firstName: { _eq: "lee" }})
  usersThatAreBots: users(where: { bot: { _eq: true  })
}

In my reason-apollo app, the user can specify these filters and so the where is constructed in my app and passed via the query's variables to the appropriate connection.

module GetUsers = [%graphql
  {|
  query GetUsers($where: WhereInput!){
    reports(first: 100, where: $where }) {
      ...
    }
  }
|}
];

In order to construct the where, I have to specify all the Some and None values so it matches the type.

let where = {
  username: Some({_eq: "lee"})
  bot: None
}

Here's the problematic part, when I use this where as variables for the query, this None will be transformed to nil and send to the GraphQL server. As nil isn't valid input, the server will return a 500.

I'm quite new to the Reason and Apollo game, but I guess the fix for this case would be to use {} rather than nill as None value or remove the entries that have a None value.

What do you think?

[baransu]

That's an issue in graphql_ppx that reason-apollo is using. You can track it here: mhallin/graphql_ppx#59.

[Willianvdv]

Thanks for your reply @baransu! I'll track that issue.

[Willianvdv]

@baransu I saw that glennsl/bs-json/issues/50 got resolved, but I have troubles understanding how I can apply this. Can you help me how I can omit the null values from the where I've posted in the example?

[baransu]

The issue still exists in mhallin/graphql_ppx#59. Please check my latest comment. I know how this could be fixed but I'm missing knowledge about OCaml AST generation and how to implement it.