# frozen_string_literal: true

RSpec.describe Fear::Some do
  it_behaves_like Fear::RightBiased::Right do
    let(:right) { Fear.some("value") }
  end

  subject(:some) { Fear.some(42) }

  describe "#select" do
    subject { some.select(&predicate) }

    context "predicate evaluates to true" do
      let(:predicate) { ->(v) { v > 40 } }
      it { is_expected.to eq(some) }
    end

    context "predicate evaluates to false" do
      let(:predicate) { ->(v) { v < 40 } }
      it { is_expected.to eq(Fear.none) }
    end
  end

  describe "#reject" do
    subject { some.reject(&predicate) }

    context "predicate evaluates to true" do
      let(:predicate) { ->(v) { v > 40 } }
      it { is_expected.to eq(Fear.none) }
    end

    context "predicate evaluates to false" do
      let(:predicate) { ->(v) { v < 40 } }
      it { is_expected.to eq(some) }
    end
  end

  describe "#get" do
    subject { some.get }
    it { is_expected.to eq(42) }
  end

  describe "#or_nil" do
    subject { some.or_nil }
    it { is_expected.to eq(42) }
  end

  describe "#empty?" do
    subject { some.empty? }
    it { is_expected.to eq(false) }
  end

  describe "#match" do
    context "matched" do
      subject do
        some.match do |m|
          m.some(->(x) { x > 2 }) { |x| x * 2 }
          m.none { "noop" }
        end
      end

      it { is_expected.to eq(84) }
    end

    context "nothing matched and no else given" do
      subject do
        proc do
          some.match do |m|
            m.some(->(x) { x < 2 }) { |x| x * 2 }
            m.none { "noop" }
          end
        end
      end

      it { is_expected.to raise_error(Fear::MatchError) }
    end

    context "nothing matched and else given" do
      subject do
        some.match do |m|
          m.none { |x| x * 2 }
          m.else { :default }
        end
      end

      it { is_expected.to eq(:default) }
    end
  end

  describe "#to_s" do
    subject { some.to_s }

    it { is_expected.to eq("#<Fear::Some get=42>") }
  end

  describe "pattern matching" do
    subject { Fear.xcase("Some(v : Integer)") { |v:| "matched #{v}" }.call_or_else(var) { "nothing" } }

    context "some of int" do
      let(:var) { Fear.some(42) }

      it { is_expected.to eq("matched 42") }
    end

    context "some of string" do
      let(:var) { Fear.some("42") }

      it { is_expected.to eq("nothing") }
    end

    context "not some" do
      let(:var) { "42" }

      it { is_expected.to eq("nothing") }
    end
  end
end