statsd_spec.rb

require 'spec_helper'

describe Datadog::Statsd do
  let(:socket) { FakeUDPSocket.new(copy_message: true) }

  subject do
    described_class.new('localhost', 1234,
      namespace: namespace,
      sample_rate: sample_rate,
      tags: tags,
      logger: logger,
      telemetry_flush_interval: -1,
      origin_detection: origin_detection,
      container_id: container_id,
    )
  end

  let(:container_id) { nil }
  let(:namespace) { 'sample_ns' }
  let(:sample_rate) { nil }
  let(:tags) { %w[abc def] }
  let(:logger) do
    Logger.new(log).tap do |logger|
      logger.level = Logger::INFO
    end
  end
  let(:log) { StringIO.new }
  let(:origin_detection) do
      # Only turn off origin detection for linux, other
      # platforms should work as before even with it enabled.
      !RUBY_PLATFORM.include?("linux")
  end

  before do
    allow(Socket).to receive(:new).and_return(socket)
    allow(UDPSocket).to receive(:new).and_return(socket)
  end

  describe '#initialize' do
    context 'when using provided values' do
      it 'sets the host correctly' do
        expect(subject.host).to eq 'localhost'
      end

      it 'sets the port correctly' do
        expect(subject.port).to eq 1234
      end

      it 'sets the namespace' do
        expect(subject.namespace).to eq 'sample_ns'
      end

      it 'sets the right tags' do
        expect(subject.tags).to eq %w[abc def]
      end

      context 'when using tags in a hash' do
        let(:tags) do
          {
            one: 'one',
            two: 'two',
          }
        end

        it 'sets the right tags' do
          expect(subject.tags).to eq %w[one:one two:two]
        end
      end
    end

    context 'when using environment variables' do
      subject do
        described_class.new(
          namespace: namespace,
          sample_rate: sample_rate,
          tags: %w[abc def]
        )
      end


      around do |example|
        ClimateControl.modify(
          'DD_AGENT_HOST' => 'myhost',
          'DD_DOGSTATSD_PORT' => '4321',
          'DD_ENTITY_ID' => '04652bb7-19b7-11e9-9cc6-42010a9c016d',
          'DD_ENV' => 'staging',
          'DD_SERVICE' => 'billing-service',
          'DD_VERSION' => '0.1.0-alpha',
          'DD_TAGS' => 'ghi,team:qa'
        ) do
          example.run
        end
      end

      it 'sets the host using the env var DD_AGENT_HOST' do
        expect(subject.host).to eq 'myhost'
      end

      it 'sets the port using the env var DD_DOGSTATSD_PORT' do
        expect(subject.port).to eq 4321
      end

      it 'sets the entity tag using ' do
        expect(subject.tags).to match_array [
          'abc',
          'def',
          'ghi',
          'env:staging',
          'service:billing-service',
          'team:qa',
          'version:0.1.0-alpha',
          'dd.internal.entity_id:04652bb7-19b7-11e9-9cc6-42010a9c016d'
        ]
      end
    end

    context 'when using default values' do
      subject do
        described_class.new
      end

      it 'sets the host to default values' do
        expect(subject.host).to eq '127.0.0.1'
      end

      it 'sets the port to default values' do
        expect(subject.port).to eq 8125
      end

      it 'sets no namespace' do
        expect(subject.namespace).to be_nil
      end

      it 'sets no tags' do
        expect(subject.tags).to be_empty
      end
    end

    context 'when testing connection type' do
      let(:fake_socket) do
        FakeUDPSocket.new(copy_message: true)
      end

      context 'when using a host and a port' do
        before do
          allow(UDPSocket).to receive(:new).and_return(fake_socket)
        end

        it 'uses an UDP socket' do
          expect(subject.transport_type).to eq :udp
        end

        it 'gives the right default size to the message buffer' do
          expect(Datadog::Statsd::MessageBuffer)
            .to receive(:new)
            .with(anything, hash_including(max_payload_size: 1_432))

          subject
        end
      end

      context 'when using a socket_path' do
        subject do
          described_class.new(
            namespace: namespace,
            sample_rate: sample_rate,
            socket_path: '/tmp/socket'
          )
        end

        it 'uses an UDS socket' do
          expect(subject.transport_type).to eq :uds
        end

        it 'gives the right default size to the message buffer' do
          expect(Datadog::Statsd::MessageBuffer)
            .to receive(:new)
            .with(anything, hash_including(max_payload_size: 8_192))

          subject
        end
      end
    end
  end

  describe '#open' do
    before do
      # avoid initializing Forwarder, but call the real Statsd#new
      allow(Datadog::Statsd::Forwarder)
        .to receive(:new)
        .and_return(instance_double(Datadog::Statsd::Forwarder, flush: true, close: true))
    end

    it 'builds an instance of statsd correctly' do
      expect(described_class)
        .to receive(:new)
        .with('localhost', 1234,
          namespace: namespace,
          sample_rate: sample_rate,
          tags: tags,
        )

      described_class.open('localhost', 1234,
        namespace: namespace,
        sample_rate: sample_rate,
        tags: tags,
      ) {}
    end

    describe 'with a fake #new' do
      before do
        allow(described_class).to receive(:new).and_return(fake_statsd)
      end

      let(:fake_statsd) do
        instance_double(described_class, close: true)
      end

      it 'yields the statsd instance' do
        expect do |block|
          described_class.open(&block)
        end.to yield_with_args(fake_statsd)
      end

      it 'closes the statsd instance' do
        expect(fake_statsd).to receive(:close)

        described_class.open {}
      end

      it 'ensures the statsd instance is closed' do
        expect(fake_statsd).to receive(:close)

        # rubocop:disable Lint/RescueWithoutErrorClass
        described_class.open do
          raise 'stop'
        end rescue nil
        # rubocop:enable Lint/RescueWithoutErrorClass
      end
    end

    it 'does not hide creation errors' do
      expect do
        described_class.open(1,2,3,4,5) {}
      end.to raise_error(ArgumentError)
    end

    it 'forwards the namespace keywor argument correctly' do
      expect(described_class.open("host", namespace: "ns") { |statsd| statsd.namespace }).to eq 'ns'
    end
  end

  describe '#increment' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'foobar:1|c' do
      let(:basic_action) do
        subject.increment('foobar', tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the increment' do
      subject.increment('foobar')
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('foobar:1|c')
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'formats the message according to the statsd spec' do
        subject.increment('foobar', sample_rate: 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1|c|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the increment with the sample rate' do
        subject.increment('foobar', 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1|c|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.increment('foobar', sample_rate: 0.5, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1|c|@0.5'
      end
    end

    context 'with a increment by' do
      it 'increments by the number given' do
        subject.increment('foobar', by: 5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:5|c'
      end
    end
  end

  describe '#decrement' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'foobar:-1|c' do
      let(:basic_action) do
        subject.decrement('foobar', tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the decrement' do
      subject.decrement('foobar')
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'foobar:-1|c'
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the decrement with the sample rate' do
        subject.decrement('foobar', sample_rate: 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:-1|c|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the decrement with the sample rate' do
        subject.decrement('foobar', 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:-1|c|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.decrement('foobar', sample_rate: 0.5, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:-1|c|@0.5'
      end
    end

    context 'with a decrement by' do
      it 'decrements by the number given' do
        subject.decrement('foobar', by: 5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:-5|c'
      end
    end
  end

  describe '#count' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'foobar:123|c' do
      let(:basic_action) do
        subject.count('foobar', 123, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the count' do
      subject.count('foobar', 123)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'foobar:123|c'
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the count with sample rate' do
        subject.count('foobar', 123, 0.1)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:123|c|@0.1'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.count('foobar', 123, sample_rate: 0.1, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:123|c|@0.1'
      end
    end
  end

  describe '#gauge' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'begrutten-suffusion:536|g' do
      let(:basic_action) do
        subject.gauge('begrutten-suffusion', 536, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the gauge' do
      subject.gauge('begrutten-suffusion', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|g'
    end

    it 'sends the gauge with sequential values' do
      subject.gauge('begrutten-suffusion', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|g'

      subject.gauge('begrutten-suffusion', -107.3)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:-107.3|g', bytes_sent: 1119, packets_sent: 1
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the gauge with the sample rate' do
        subject.gauge('begrutten-suffusion', 536, sample_rate: 0.1)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|g|@0.1'
      end
    end

    describe 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'formats the message according to the statsd spec' do
        subject.gauge('begrutten-suffusion', 536, 0.1)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|g|@0.1'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.gauge('begrutten-suffusion', 536, sample_rate: 0.1, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|g|@0.1'
      end
    end
  end

  describe '#histogram' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'ohmy:536|h' do
      let(:basic_action) do
        subject.histogram('ohmy', 536, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the histogram' do
      subject.histogram('ohmy', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'ohmy:536|h'
    end

    it 'sends the histogram with sequential values' do
      subject.histogram('ohmy', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'ohmy:536|h'

      subject.histogram('ohmy', -107.3)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'ohmy:-107.3|h', bytes_sent: 1104, packets_sent: 1
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the histogram with the sample rate' do
        subject.histogram('ohmy', 536, sample_rate: 0.1)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'ohmy:536|h|@0.1'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.histogram('ohmy', 536, sample_rate: 0.1, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'ohmy:536|h|@0.1'
      end
    end
  end

  describe '#set' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'myset:536|s' do
      let(:basic_action) do
        subject.set('myset', 536, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the set' do
      subject.set('my.set', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'my.set:536|s'
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the set with the sample rate' do
        subject.set('my.set', 536, sample_rate: 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'my.set:536|s|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the set with the sample rate' do
        subject.set('my.set', 536, 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'my.set:536|s|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.set('my.set', 536, sample_rate: 0.5, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'my.set:536|s|@0.5'
      end
    end
  end

  describe '#timing' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'foobar:500|ms' do
      let(:basic_action) do
        subject.timing('foobar', 500, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the timing' do
      subject.timing('foobar', 500)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'foobar:500|ms'
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.timing('foobar', 500, sample_rate: 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:500|ms|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.timing('foobar', 500, 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:500|ms|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.timing('foobar', 500, sample_rate: 0.5, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:500|ms|@0.5'
      end
    end
  end

  describe '#time' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    let(:before_date) do
      DateTime.new(2020, 2, 25, 12, 12, 12)
    end

    let(:after_date) do
      DateTime.new(2020, 2, 25, 12, 12, 13)
    end

    before do
      Timecop.freeze(before_date)
      allow(Process).to receive(:clock_gettime).and_return(0)
    end

    it_behaves_like 'a metrics method', 'foobar:1000|ms' do
      let(:basic_action) do
        subject.time('foobar', tags: action_tags) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)
      end
    end

    context 'when actually testing time' do
      it 'sends the timing' do
        subject.time('foobar') do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|ms'
      end

      it 'ensures the timing is sent' do
        # rubocop:disable Lint/RescueWithoutErrorClass
        subject.time('foobar') do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
          raise 'stop'
        end rescue nil
        # rubocop:enable Lint/RescueWithoutErrorClass

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|ms'
      end
    end

    it 'returns the result of the block' do
      expect(subject.time('foobar') { 'test' }).to eq 'test'
    end

    it 'does not catch errors if block is failing' do
      expect do
        subject.time('foobar') do
          raise 'yolo'
        end
      end.to raise_error(StandardError, 'yolo')
    end

    it 'can run without "PROCESS_TIME_SUPPORTED"' do
      stub_const('PROCESS_TIME_SUPPORTED', false)

      expect do
        subject.time('foobar') {}
      end.not_to raise_error
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.time('foobar', sample_rate: 0.5) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|ms|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.time('foobar', 0.5) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|ms|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.time('foobar', sample_rate: 0.5, pre_sampled: true) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|ms|@0.5'
      end
    end
  end

  describe '#distribution_time' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    let(:before_date) do
      DateTime.new(2020, 2, 25, 12, 12, 12)
    end

    let(:after_date) do
      DateTime.new(2020, 2, 25, 12, 12, 13)
    end

    before do
      Timecop.freeze(before_date)
      allow(Process).to receive(:clock_gettime).and_return(0)
    end

    it_behaves_like 'a metrics method', 'foobar:1000|d' do
      let(:basic_action) do
        subject.distribution_time('foobar', tags: action_tags) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)
      end
    end

    context 'when actually testing time' do
      it 'sends the timing' do
        subject.distribution_time('foobar') do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|d'
      end

      it 'ensures the timing is sent' do
        # rubocop:disable Lint/RescueWithoutErrorClass
        subject.distribution_time('foobar') do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
          raise 'stop'
        end rescue nil
        # rubocop:enable Lint/RescueWithoutErrorClass

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|d'
      end
    end

    it 'returns the result of the block' do
      expect(subject.distribution_time('foobar') { 'test' }).to eq 'test'
    end

    it 'does not catch errors if block is failing' do
      expect do
        subject.distribution_time('foobar') do
          raise 'yolo'
        end
      end.to raise_error(StandardError, 'yolo')
    end

    it 'can run without "PROCESS_TIME_SUPPORTED"' do
      stub_const('PROCESS_TIME_SUPPORTED', false)

      expect do
        subject.distribution_time('foobar') {}
      end.not_to raise_error
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.distribution_time('foobar', sample_rate: 0.5) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|d|@0.5'
      end
    end

    context 'with a sample rate like statsd-ruby' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the timing with the sample rate' do
        subject.distribution_time('foobar', 0.5) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|d|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.distribution_time('foobar', sample_rate: 0.5, pre_sampled: true) do
          Timecop.travel(after_date)
          allow(Process).to receive(:clock_gettime).and_return(1)
        end

        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'foobar:1000|d|@0.5'
      end
    end
  end

  describe '#distribution' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it_behaves_like 'a metrics method', 'begrutten-suffusion:536|d' do
      let(:basic_action) do
        subject.distribution('begrutten-suffusion', 536, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends the distribution' do
      subject.distribution('begrutten-suffusion', 536)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|d'
    end

    context 'with a sample rate' do
      before do
        allow(subject).to receive(:rand).and_return(0)
      end

      it 'sends the set with the sample rate' do
        subject.distribution('begrutten-suffusion', 536, sample_rate: 0.5)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|d|@0.5'
      end
    end

    context 'with pre sampling' do
      before do
        allow(subject).to receive(:rand).and_return(1)
      end

      it 'sends the sample rate without additional sampling' do
        subject.distribution('begrutten-suffusion', 536, sample_rate: 0.5, pre_sampled: true)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'begrutten-suffusion:536|d|@0.5'
      end
    end
  end

  describe '#event' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }
    let(:title) { 'this is a title' }
    let(:text) { 'this is a longer text' }
    let(:timestamp) do
      Time.parse('01-01-2000').to_i
    end

    it_behaves_like 'a taggable method', '_e{15,21}:this is a title|this is a longer text', metrics: 0, events: 1 do
      let(:basic_action) do
        subject.event(title, text, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends events with title and text' do
      subject.event(title, text)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('_e{15,21}:this is a title|this is a longer text', metrics: 0, events: 1)
    end

    context 'when having line breaks in text or title' do
      let(:title) { "this is a\ntitle" }
      let(:text) { "this is a longer\ntext" }

      it 'sends events with title and text' do
        subject.event(title, text)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_e{16,22}:this is a\ntitle|this is a longer\ntext', metrics: 0, events: 1)
      end

      context 'when truncate_if_too_long option is specified' do
        let(:options) { { truncate_if_too_long: true } }

        it 'does not raise error' do
          expect do
            subject.event(title, text, options)
          end.not_to raise_error
        end
      end
    end

    context 'with a known alert type' do
      it 'sends events with title and text along with a tag for the alert type' do
        subject.event(title, text, alert_type: 'warning')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_e{15,21}:this is a title|this is a longer text|t:warning', metrics: 0, events: 1)
      end
    end

    context 'with an unknown alert type' do
      it 'sends events with title and text along with a tag for the alert type' do
        subject.event(title, text, alert_type: 'yolo')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_e{15,21}:this is a title|this is a longer text|t:yolo', metrics: 0, events: 1)
      end
    end

    context 'with a known priority' do
      it 'sends events with title and text along with a tag for the priority' do
        subject.event(title, text, priority: 'low')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_e{15,21}:this is a title|this is a longer text|p:low', metrics: 0, events: 1)
      end
    end

    context 'with an unknown priority' do
      it 'sends events with title and text along with a tag for the priority' do
        subject.event(title, text, priority: 'yolo')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_e{15,21}:this is a title|this is a longer text|p:yolo', metrics: 0, events: 1)
      end
    end

    context 'with a timestamp event date' do
      it 'sends events with title and text along with a date timestamp' do
        subject.event(title, text, date_happened: timestamp)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|d:#{timestamp}", metrics: 0, events: 1)
      end
    end

    context 'with a string event date' do
      it 'sends events with title and text along with a date timestamp' do
        subject.event(title, text, date_happened: timestamp.to_s)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|d:#{timestamp}", metrics: 0, events: 1)
      end
    end

    context 'with a hostname' do
      it 'sends events with title and text along with a hostname' do
        subject.event(title, text, hostname: 'chihiro')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|h:chihiro", metrics: 0, events: 1)
      end
    end

    context 'with an aggregation key' do
      it 'sends events with title and text along with the aggregation key' do
        subject.event(title, text, aggregation_key: 'key 1')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|k:key 1", metrics: 0, events: 1)
      end
    end

    context 'with an source type name' do
      it 'sends events with title and text along with the source type name' do
        subject.event(title, text, source_type_name: 'source 1')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|s:source 1", metrics: 0, events: 1)
      end
    end

    context 'with several parameters (hostname, alert_type, priority, source)' do
      it 'sends events with title and text along with all the parameters' do
        subject.event(title, text, hostname: 'myhost', alert_type: 'warning', priority: 'low', source_type_name: 'source')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_e{15,21}:this is a title|this is a longer text|h:myhost|p:low|s:source|t:warning", metrics: 0, events: 1)
      end
    end
  end

  describe '#service_check' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }
    let(:name) { 'windmill' }
    let(:status) { 'grinding' }
    let(:timestamp) do
      Time.parse('01-01-2000').to_i
    end

    it_behaves_like 'a taggable method', '_sc|windmill|grinding', metrics: 0, service_checks: 1 do
      let(:basic_action) do
        subject.service_check(name, status, tags: action_tags)
        subject.flush(sync: true)
      end
    end

    it 'sends service check with name and status' do
      subject.service_check(name, status)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('_sc|windmill|grinding', metrics: 0, service_checks: 1)
    end

    context 'with hostname' do
      it 'sends service check with name and status along with hostname' do
        subject.service_check(name, status, hostname: 'amsterdam')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_sc|windmill|grinding|h:amsterdam', metrics: 0, service_checks: 1)
      end
    end

    context 'with message' do
      it 'sends service check with name and status along with message' do
        subject.service_check(name, status, message: 'the wind is rising')
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry('_sc|windmill|grinding|m:the wind is rising', metrics: 0, service_checks: 1)
      end
    end

    context 'with integer timestamp' do
      it 'sends service check with name and status along with timestamp' do
        subject.service_check(name, status, timestamp: timestamp)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_sc|windmill|grinding|d:#{timestamp}", metrics: 0, service_checks: 1)
      end
    end

    context 'with string timestamp' do
      it 'sends service check with name and status along with timestamp' do
        subject.service_check(name, status, timestamp: timestamp.to_s)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_sc|windmill|grinding|d:#{timestamp}", metrics: 0, service_checks: 1)
      end
    end

    context 'with several parameters (hostname, message, timestamp)' do
      it 'sends service check with name and status along with all parameters' do
        subject.service_check(name, status, hostanme: 'amsterdam', message: 'the wind is rising', timestamp: timestamp.to_s)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry("_sc|windmill|grinding|d:#{timestamp}|m:the wind is rising", metrics: 0, service_checks: 1)
      end
    end
  end

  describe '#close' do
    before do
      # do some writing so the socket is opened
      subject.increment('lol')
      subject.flush(sync: true)
    end

    context 'when not using the flush option' do
      it 'closes the socket' do
        expect(socket).to receive(:close)

        subject.close(flush: false)
      end

      it 'does not write buffered data to the socket' do
        subject.increment('test')

        expect(socket).not_to receive(:send)

        subject.close(flush: false)
      end
    end

    context 'when using the flush option' do
      it 'closes the socket' do
        expect(socket).to receive(:close)

        subject.close
      end

      it 'writes the buffered data to the socket' do
        subject.increment('test')

        expect(socket).to receive(:send)

        subject.close
      end
    end
  end

  # TODO: This specs will have to move to another class (a responsibility that we will have to separate)
  describe 'Stat names' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it 'accepts any object with #to_s as a stat name' do
      o = double('a stat', to_s: 'yolo')

      subject.increment(o)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('yolo:1|c')
    end

    it 'accepts a class name as a stat name' do
      subject.increment(Object)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('Object:1|c')
    end

    it 'replaces Ruby constants delimeter with graphite package name' do
      class Datadog::Statsd::SomeClass; end
      subject.increment(Datadog::Statsd::SomeClass)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'Datadog.Statsd.SomeClass:1|c'
    end

    it 'replaces statsd reserved chars in the stat name' do
      subject.increment('ray@hostname.blah|blah.blah:blah')
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'ray_hostname.blah_blah.blah_blah:1|c'
    end

    it 'works with frozen strings' do
      subject.increment('some-stat'.freeze)
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry('some-stat:1|c')
    end
  end

  # TODO: This specs will have to move to another class (a responsibility that we will have to separate)
  describe 'Tag names' do
    let(:namespace) { nil }
    let(:sample_rate) { nil }
    let(:tags) { nil }

    it 'replaces reserved chars for tags' do
      subject.increment('stat', tags: ['name:foo,bar|foo'])
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'stat:1|c|#name:foobarfoo'
    end

    it 'handles the cases when some tags are frozen strings' do
      subject.increment('stat', tags: ['first_tag'.freeze, 'second_tag'])
      subject.flush(sync: true)
    end

    it 'converts all values to strings' do
      tag = double('a tag', to_s: 'yolo')

      subject.increment('stat', tags: [tag])
      subject.flush(sync: true)

      expect(socket.recv[0]).to eq_with_telemetry 'stat:1|c|#yolo'
    end
  end

  describe 'External env' do
    let(:tags) { nil }

    before do
      ENV['DD_EXTERNAL_ENV'] = 'it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759'
    end

    context 'with origin detection configured on' do
      let(:origin_detection) { true }
      let(:container_id) { "container" }

      it 'outputs the external env value' do
        subject.gauge('thing', 42)
        subject.flush(sync: true)

        # With the lengthy external env being included in the telemetry payload, we send multiple payloads
        # and need to capture them all.
        packets = []
        while (packet = socket.recv)
          packets << packet[0]
        end
        combined_message = packets.join("\n")

        expect(combined_message).to eq_with_telemetry('sample_ns.thing:42|g|c:container|e:it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759',
                                                      container: 'container', external_env: 'it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759') 
      end
    end

    context 'with origin detection configured off' do
      let(:origin_detection) { false }

      it 'does not output the external env value' do
        subject.gauge('thing', 42)
        subject.flush(sync: true)

        expect(socket.recv[0]).to eq_with_telemetry 'sample_ns.thing:42|g'
      end
    end
  end
end