# frozen_string_literal: true

require_relative '../spec_helper' # Use the RSpec framework

# Load the class under test
require_relative '../../lib/mini_kraken/core/fail'

module MiniKraken
  module Core
    describe Fail do
      subject { Fail.instance }

      context 'Initialization:' do
        it 'should have one instance' do
          expect { Fail.instance }.not_to raise_error
        end

        it 'should know its name' do
          expect(subject.name).to eq('fail')
        end
      end # context

      context 'Provided services:' do
        let(:ctx) { Context.new }

        it 'should unconditionally return a failure result' do
          solver = nil
          expect { solver = subject.solver_for([], ctx) }.not_to raise_error

          # Solver quacks like a Fiber
          dummy_arg = double('dummy-stuff')
          result = solver.resume(dummy_arg)
          expect(result).to be_failure

          # Only one "solution", next 'resume' call should return nil
          result = solver.resume(dummy_arg)
          expect(result).to be_nil
        end
      end # context
    end # describe
  end # module
end # module