it 'test to demonstrate the validation issue' do subject.params do requires :a, type: String, allow_blank: false, values: %w[x y z] given a: ->(val) { val == 'z' } do requires :inner3, type: Array, allow_blank: false do requires :bar, type: String, allow_blank: false given bar: ->(val) { val == 'b' } do requires :baz, type: Array do requires :new_category, type: String end end given bar: ->(val) { val == 'c' } do requires :baz, type: Array do requires :baz_category, type: String end end end end end subject.post('/nested-dependency') { declared(params).to_json } test = { a: 'z', inner3: [ { bar: 'b', baz: [{ new_category: 'nope' }] }, { bar: 'c', baz: [{ baz_category: 'nope' }] } ] } post '/nested-dependency', **test expect(last_response.status).to eq(200) end