require 'rom/relation'
require 'rom/command'
require 'rom/plugins/command/schema'

RSpec.describe ROM::Plugins::Command::Schema do
  describe '.build' do
    let(:command_class) do
      Class.new(ROM::Command) { use :schema }
    end

    context 'when relation has no schema defined' do
      let(:relation) do
        instance_double(ROM::Relation, schema?: false)
      end

      it 'sets default input handler when command does not have a custom one' do
        command = Class.new(command_class).build(relation)

        expect(command.input).to be(ROM::Command.input)
      end

      it 'sets custom input handler when command defines it' do
        my_handler = double(:my_handler)

        command = Class.new(command_class) { input my_handler }.build(relation)

        expect(command.input).to be(my_handler)
      end

      it 'sets custom input handler when it is passed as an option' do
        my_handler = double(:my_handler)

        command = Class.new(command_class).build(relation, input: my_handler)

        expect(command.input).to be(my_handler)
      end
    end

    context 'when relation has a schema' do
      let(:relation) do
        instance_double(ROM::Relation, schema?: true, schema_hash: schema_hash)
      end

      let(:schema_hash) do
        double(:schema_hash)
      end

      it 'sets schema hash as input handler' do
        command = Class.new(command_class).build(relation)

        expect(command.input).to be(schema_hash)
      end

      it 'sets a composed input handler with schema hash and a custom one' do
        my_handler = double(:my_handler)

        command = Class.new(command_class) { input my_handler }.build(relation)

        expect(my_handler).to receive(:[]).with('some value').and_return('my handler')
        expect(schema_hash).to receive(:[]).with('my handler').and_return('a tuple')

        expect(command.input['some value']).to eql('a tuple')
      end
    end
  end
end