Cannot distinguish between missing arguments and field not wanted

[jml]

As per #77

On the example schema, this query:

{
  name
  owner {
    name
  }
}

Returns:

{
  "data": {
    "dog": {
      "name": "Mortgage",
      "owner": null
    }
  },
  "errors": [
    {
      "message": "No value provided for Name {getNameText = \"dogCommand\"}, and no default specified."
    }
  ]
}

I would expect it to return:

{
  "data": {
    "dog": {
      "name": "Mortgage",
      "owner": {
        "name": "jml"
      }
    }
  }
}

[jml]

The issue isn't that nested queries are broken, it's that:

• we try to match the incoming queried field (here "owner") against all fields in the schema
• the schema's doesKnowCommand is being checked before the schema's owner
• for fields with arguments (such as doesKnowCommand), the first thing we do is check for provided arguments
• the user-queried "owner": does not provide arguments, and doesKnowCommand requires an argument, so we error out