rspecで時間操作をする

今まではtimecop使ってたんだけど、細かい制御までは特にする必要もなかったので ActiveSupport::Testing::TimeHelpers を使ってみる

spec/rails_helper.rbに以下を追記

# This file is copied to spec/ when you run 'rails generate rspec:install'
require 'spec_helper'
ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../config/environment', __dir__)
abort("The Rails environment is running in production mode!") if Rails.env.production?
require 'rspec/rails'
require 'webdrivers'
require 'email_spec'
require 'email_spec/rspec'

Dir[Rails.root.join('spec', 'support', '**', '*.rb')].sort.each { |f| require f }

# Checks for pending migrations and applies them before tests are run.
# If you are not using ActiveRecord, you can remove these lines.
begin
  ActiveRecord::Migration.maintain_test_schema!
rescue ActiveRecord::PendingMigrationError => e
  puts e.to_s.strip
  exit 1
end
RSpec.configure do |config|
  config.use_transactional_fixtures = true
  config.infer_spec_type_from_file_location!

  # Filter lines from Rails gems in backtraces.
  config.filter_rails_from_backtrace!
  # arbitrary gems may also be filtered via:
  # config.filter_gems_from_backtrace("gem name")
  
  config.include ActiveJob::TestHelper
  config.include ActiveSupport::Testing::TimeHelpers # <-- 追記
end

使いたい箇所で travel_toで囲む

context "Sample" do
  it  do
    travel_to('2020-1-1 0:00'.to_time) do
      # do test
    end
  end
end

aroundを使って広範囲に反映する

context "Sample" do
  around do |e|
    travel_to('2020-1-1 0:00'.to_time) { e.run }
  end

  it  do
    # do test
  end

  it  do
    # do test
  end
end