Undefined method 'merge' for empty hash

[shlima]

# works
present :aggregations, []

# raises an <NoMethodError: undefined method `merge' for :aggregations:Symbol>
present :aggregations, {}

"Framework Trace": [
      {
        "exception_object_id": 70108428652700,
        "id": 0,
        "trace": "grape (1.2.4) lib/grape/dsl/inside_route.rb:332:in `present'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 2,
        "trace": "grape (1.2.4) lib/grape/endpoint.rb:57:in `call'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 3,
        "trace": "grape (1.2.4) lib/grape/endpoint.rb:57:in `block (2 levels) in generate_api_method'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 4,
        "trace": "activesupport (6.0.0) lib/active_support/notifications.rb:182:in `instrument'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 5,
        "trace": "grape (1.2.4) lib/grape/endpoint.rb:56:in `block in generate_api_method'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 6,
        "trace": "grape (1.2.4) lib/grape/endpoint.rb:263:in `block in run'"
      },
      {
        "exception_object_id": 70108428652700,
        "id": 7,
        "trace": "activesupport (6.0.0) lib/active_support/notifications.rb:182:in `instrument'"
      },

[shlima]

I've made a temp solution:

present :aggregations, {}, with: GrapeSerializer

# frozen_string_literal: true

class GrapeSerializer
  def self.represent(object, *)
    object.as_json
  end
end

[dblock]

What's the stack for this error?

Try writing a unit test in Grape?