RSpec.describe Rule::Check do
  include_context 'predicates'

  describe '#call' do
    context 'with 1-level nesting' do
      subject(:rule) do
        Rule::Check.new(eql?.curry(1), name: :compare, keys: [:num])
      end

      it 'applies predicate to args extracted from the input' do
        expect(rule.(num: 1)).to be_success
        expect(rule.(num: 2)).to be_failure

        expect(rule.(num: 1).to_ast).to eql(
          [:input, [:compare, [
            :result, [1, [:check, [:compare, [:predicate, [:eql?, [[:left, 1], [:right, 1]]]]]]]]]
          ]
        )
      end
    end

    context 'with 2-levels nesting' do
      subject(:rule) do
        Rule::Check.new(eql?, name: :compare, keys: [[:nums, :left], [:nums, :right]])
      end

      it 'applies predicate to args extracted from the input' do
        expect(rule.(nums: { left: 1, right: 1 })).to be_success
        expect(rule.(nums: { left: 1, right: 2 })).to be_failure
      end

      #check rules reverse the order of params to enable cases like `left.gt(right)` to work
      it 'curries args properly' do
        result = rule.(nums: { left: 1, right: 2 })

        expect(result.to_ast).to eql([
          :input, [:compare, [
            :result, [1, [:check, [:compare, [:predicate, [:eql?, [[:left, 2], [:right, 1]]]]]]]]
          ]
        ])
      end
    end
  end
end