TravelToJavascript

This gem provides a helper travel_to_javascript that locks time in javascript. It supports rspec and minitest using capybara.

Override Date and Date.now in JavaScript by args.

⚠️ cautions when using

It is not possible to stop time between pages by performing visits etc. in travel_to_javascript because JavaScript will be reloaded when the page is reloaded.
If the judgment is made on the JavaScript side when loarding the page, it may not work because the judgment may be made before executing execute_script.

Installation

Add this line to your application's Gemfile:

gem 'travel_to_javascript'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install travel_to_javascript

Usage

travel_to_javascript can be used by include TravelToJavascript.

By passing the object of Capybara::Session(ex. page) and the date and time to the argument of travel_to_javascript, the time of JavaScript in the block can be fixed at the time of the argument.

Rspec

require 'spec_helper'
require 'travel_to_javascript'

RSpec.describe 'SampleFeatureSpec', type: :feature do
  include TravelToJavascript

  it 'sample spec' do
   # NOTE: Use a JavaScript enabled driver.
    page = Capybara::Session.new(:headless_chrome, TestApp)
    travel_to_javascript(page, DateTime.parse('2000-01-01 1:11:11.111+9:00')) do
      page.execute_script('console.error(Date.now(), new Date())')
      pp page.driver.browser.manage.logs.get(:browser).map(&:message)
      # locks time by args in block.
      # => ["console-api 2:32 946656671111 Sat Jan 01 2000 01:11:11 GMT+0900"]
    end
    page.execute_script('console.error(Date.now(), new Date())')
    pp page.driver.browser.manage.logs.get(:browser).map(&:message)
    # restore time outside block.
    # => ["console-api 2:32 1586652460142 Sun Apr 12 2020 09:47:40 GMT+0900"]
  end
end

Minitest

require 'test_helper'
require 'travel_to_javascript'

class SampleFeatureTest < Minitest::Test
  include TravelToJavascript

  def test_sample
     # NOTE: Use a JavaScript enabled driver.
    page = Capybara::Session.new(:headless_chrome, TestApp)
    travel_to_javascript(page, DateTime.parse('2000-01-01 1:11:11.111+9:00')) do
      page.execute_script('console.error(Date.now(), new Date())')
      pp page.driver.browser.manage.logs.get(:browser).map(&:message)
      # locks time by args in block.
      # => ["console-api 2:32 946656671111 Sat Jan 01 2000 01:11:11 GMT+0900"]
    end
    page.execute_script('console.error(Date.now(), new Date())')
    pp page.driver.browser.manage.logs.get(:browser).map(&:message)
    # restore time outside block.
    # => ["console-api 2:32 1586652460142 Sun Apr 12 2020 09:47:40 GMT+0900"]
  end
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Madogiwa0124/travel_to_javascript. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the TravelToJavascript project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.