require 'spec_helper'
require 'immutable/set'

describe Immutable::Set do
  let(:set) { S[*values] }

  describe '#grep_v' do
    let(:grep_v) { set.grep_v(String, &block) }

    shared_examples 'check filtered values' do
      it 'returns the filtered values' do
        expect(grep_v).to eq(S[*filtered])
      end
    end

    context 'without a block' do
      let(:block) { nil }

      context 'with an empty set' do
        let(:values) { [] }
        let(:filtered) { [] }

        include_examples 'check filtered values'
      end

      context 'with a single item set' do
        let(:values) { ['A'] }
        let(:filtered) { [] }

        include_examples 'check filtered values'
      end

      context "with a single item set that doesn't contain match" do
        let(:values) { [1] }
        let(:filtered) { [1] }

        include_examples 'check filtered values'
      end

      context "with a multi-item set where one isn't a match" do
        let(:values) { [2, 'C', 4] }
        let(:filtered) { [2, 4] }

        include_examples 'check filtered values'
      end
    end

    describe 'with a block' do
      let(:block) { ->(item) { item + 100 }}

      context 'resulting items are processed with the block' do
        let(:values) { [2, 'C', 4] }
        let(:filtered) { [102, 104] }

        include_examples 'check filtered values'
      end
    end
  end
end