Input field default value is ignored

[tristanlins]

Running example can found here: https://github.com/tristanlins/graphql-input-default-test

I've build a query with an input parameter, that have default values. It looks like this:

type Query {
    list(listing: Listing! = { size: 10 }): [String!]!
}

input Listing {
    size: Int! = 10
    after: String
}

Here are two things that I think are not working properly. First, I have to redefine the size in the parameter default value, even though it has a default value in the type definition.

Second, if I execute a query without overwriting listing, it works without problems. But if I just want to set the after value, I get an error that I should also define size - although actually a default value is defined.

Working query

query {
  list
}

Result

{
  "data": {
    "list": [
      "size: 10",
      "after: null"
    ]
  }
}

Failing query

query {
  list(listing: { after: "test" })
}

Result

{
  "errors": [
    {
      "message": "Validation error of type WrongType: argument 'listing' with value 'ObjectValue{objectFields=[ObjectField{name='after', value=StringValue{value='test'}}]}' is missing required fields '[size]' @ 'list'",
      "locations": [
        {
          "line": 2,
          "column": 8
        }
      ],
      "extensions": {
        "classification": "ValidationError"
      }
    }
  ],
  "data": null
}

---

Actually, my expectation would be that I do not have to specify size and always use the default value until I override size. So it is at least in the specification (or at least I understood it that way).

If no value is provided for a defined input object field and that field definition provides a default value, the default value should be used.

https://graphql.github.io/graphql-spec/June2018/#sec-Input-Objects

[vojtapol]

It seems that default values in input objects are currently not supported.