freeze_time.rb

require 'active_support/testing/time_helpers'

RSpec.configure do |config|
  config.include ActiveSupport::Testing::TimeHelpers

  config.after do
    travel_back
    Timecop.return
  end

  config.extend Module.new {
    def freeze_time_around(time = Time.current)
      around do |ex|
        time = Time.zone.parse(time) if time.is_a? String

        Timecop.freeze(time) do
          ex.run
        end
      end
    end
  }

  config.around(:each, :freeze_time) do |ex|
    time = ex.metadata[:freeze_time]

    time = case time
           when String
             Time.zone.parse(time)
           when nil, true
             Time.zone.now
           else
             time
           end

    if time
      Timecop.freeze(time) do
        ex.run
      end
    else
      ex.run
    end
  end
end

start_spec.rb

describe "Start" do
  it "should save start time", :freeze_time do
    subject.start;
    expect(subject.started_at).to eq Time.zone.now
  end
  
  context 'stop war', freeze_time: '2022-02-24' do
    it 'works' do
      expect(Date.today.to_s).to eq '2022-02-24'
    end
  end
  
  context 'with time object', freeze_time: 2.hours.since do
    it 'works' do
      # ...
    end
  end
end