# frozen_string_literal: true

describe DDTelemetry::Counter do
  subject(:counter) { described_class.new }

  describe 'new counter' do
    it 'starts at 0' do
      expect(subject.get(:erb)).to eq(0)
      expect(subject.get(:haml)).to eq(0)
    end
  end

  describe '#increment' do
    subject { counter.increment(:erb) }

    it 'increments the matching value' do
      expect { subject }
        .to change { counter.get(:erb) }
        .from(0)
        .to(1)
    end

    it 'does not increment any other value' do
      expect(counter.get(:haml)).to eq(0)
      expect { subject }
        .not_to change { counter.get(:haml) }
    end
  end

  describe '#get' do
    subject { counter.get(:erb) }

    context 'not incremented' do
      it { is_expected.to eq(0) }
    end

    context 'incremented' do
      before { counter.increment(:erb) }
      it { is_expected.to eq(1) }
    end

    context 'other incremented' do
      before { counter.increment(:haml) }
      it { is_expected.to eq(0) }
    end
  end

  describe '#labels' do
    subject { counter.labels }

    before do
      counter.increment(:erb)
      counter.increment(:erb)
      counter.increment(:haml)
    end

    it { is_expected.to contain_exactly(:haml, :erb) }
  end

  describe '#each' do
    subject do
      {}.tap do |res|
        counter.each { |label, count| res[label] = count }
      end
    end

    before do
      counter.increment(:erb)
      counter.increment(:erb)
      counter.increment(:haml)
    end

    it { is_expected.to eq(haml: 1, erb: 2) }

    it 'is enumerable' do
      expect(counter.map { |_label, count| count }.sort)
        .to eq([1, 2])
    end
  end

  describe '#to_s' do
    subject { counter.to_s }

    before do
      counter.increment(:erb)
      counter.increment(:erb)
      counter.increment(:haml)
    end

    it 'returns table' do
      expected = <<~TABLE
             │ count
        ─────┼──────
         erb │     2
        haml │     1
      TABLE

      expect(subject.strip).to eq(expected.strip)
    end
  end
end