[1.8] Default value not provided for omitted optional input object with arguments with defaults

[Envek]

Summary

If query argument is optional complex input object with arguments with default values then these default values are not provided in this input object is omitted from the query arguments

Example

Given the following query definition:

class Types::QueryType < GraphQL::Schema::Object
  field :products, Types::Product.connection_type, null: false do
    argument :filters, Types::Product::Filter, required: false, default_value: {}
  end
  def products(filters:)
    # apply filters
  end
end
class Types::Product::Filter < GraphQL::Schema::InputObject
  graphql_name "ProductFilter"
  argument :archived,            Boolean, required: false, default_value: false
  argument :status,              String,  required: false
end

Generated docs says that filters have default values:

products(
  first: Int
  after: String
  last: Int
  before: String
  filters: ProductFilter = {archived: false}
): ProductConnection!

If executing a query without filters parameter then in method empty hash is passed (not as expected):

{
  products(first: 2) {
    edges { node { id } }
  }
}

def products(filter:) # filter: {} - plain hash as provided in default_value

If executing a query with empty filters parameter then in method passed a hash with default parameter set (as expected):

{
  products(first: 2, filters: {}) {
    edges { node { id } }
  }
}

def products(filter:) # filter: {:archived=>false} - instance of Types::Product::Filter

Environment

gem graphql 1.8.5
gem graphql-batch 0.3.9
ruby 2.5.1
rails 5.2.0

Notes

I'm naturally don't want to duplicate default values from Types::Product::Filter in the default_value option in filters argument definition.

[rmosolgo]

🤔 Hmm, thanks for the detailed report. How misleading that the generated schema suggests one thing while the runtime behavior shows something else!

I wonder what the spec has to say on this, which one is right...

[N0xFF]

It actual problem? I can't reproduce in 1.9.9 with Interpreter and AST.

Executing without filter argument returns a filter object as expected.

[Envek]

Yes, with Interpreter enabled it works like it should. ✔️ @N0xFF, thank you for pointing it out!
With disabled interpreter this issue is still there, though.

The only weird case left is that you still should specify any default value for filters argument (like empty hash) or Ruby will throw exception about not provided keyword argument.

[cantino]

We just ran into this as well in our app that doesn't yet use Interpreter. Defaults are not applied for the sub-object when the field using it has a default_value of {} (or when it has no default_value at all). Is there some way we could set the parent field's default_value to something like Types::Product::Filter.defaults? I.e.g, is there some method to generate the default output of an object?

[rmosolgo]

I'm sorry, I don't really have the bandwidth to support the old runtime these days. If you're a GraphQL-Pro customer, shoot me an email and I'll keep digging, or if anyone wants to submit a PR, I'd be happy to review and help as I can.