UI2API
As more web applications make use of an interface to interact with their service layer, people now have more flexibility to set up and verify parts of their UI tests without needing to use a browser.
This simple gem makes it easy to subclass UI2API::Base
and provide all of the information necessary
to interact with the different REST endpoints available in your application.
This code is designed to be used with the watir_model gem. The Model stores data in a way that makes it easy to compare the input and output from both the API and the UI.
Note that while this gem can be used as the basis of an API Testing suite, its primary focus is on comparing input and output from UI to API and back.
Installation
Add this line to your application's Gemfile:
gem 'ui2api'
And then execute:
$ bundle
Or install it yourself as:
$ gem install ui2api
Usage
-
Set the base url
UI2API::Base.base_url = 'https://restful-booker.herokuapp.com'
-
Create a subclass with an endpoint:
module API class Booking < UI2API::Base def self.endpoint 'booking' end end end
-
Make API calls
booking = {firstname: 'Trey', lastname: 'Ruecker', totalprice: 83, depositpaid: true, bookingdates: {checkin: '3/23/2019', checkout: '3/27/2019'}} API::Booking.create(booking)
-
The Array or Hash of results is accessed with
#data
booking = {firstname: 'David', lastname: 'Jones', totalprice: 183, depositpaid: true, bookingdates: {checkin: '3/23/2019', checkout: '3/27/2019'}} created_booking = API::Booking.create(booking) booking_id = created_booking.data[:bookingid] stored_booking = API::Booking.show(id: booking_id).data expect(stored_booking).to eq booking
-
Use Watir Model
Note that the code in the previous example will actually fail. This is because we are storing dates as
String
values and the inputString
does not match the outputString
Hashes are hard to compare, which is why we have
WatirModel
. WatirModel is designed to store the canonical representation of related data in the appropriate data type, specifically so that data can be correctly compared.module Model class BookingDates < WatirModel key(:checkin, data_type: Date) { Faker::Date.forward } key(:checkout, data_type: Date) { checkin + 4 } end class Booking < WatirModel key(:firstname) { Faker::Name.first_name } key(:lastname) { Faker::Name.last_name } key(:totalprice, data_type: Integer) { Faker::Commerce.price.round } key(:depositpaid) { true } key(:bookingdates, data_type: BookingDates) { BookingDates.new } key(:additionalneeds) end end
Because we have a model class defined that is named the same as the API class,
UI2API
will automatically attempt to create an instance of the model from the return value of the API call. It is accessible from a method based on the name of the API/Model classes, so in this case#booking
:booking = Model::Booking.new created_booking = API::Booking.create(booking) booking_id = created_booking.data[:bookingid] stored_booking = API::Booking.show(id: booking_id).booking expect(stored_booking).to eq booking
-
Customize
You have a subclass, so if you need to add or change things before or after a call, just override the
UI2API
method in your subclass:module API class Booking < UI2API::Base attr_reader :id def initialize(*) super return if @data.is_a?(Array) @id = @data[:bookingid] end end end
Now we can use this like so:
booking = Model::Booking.new created_booking = API::Booking.create(booking) expect(created_booking.id).to eq created_booking.data[:bookingid]
Because this pattern comes in very handy, you can use
#define_attribute
to do the same thing:module API class Booking < UI2API::Base def initialize(*) super return if @data.is_a?(Array) define_attribute(:id, @data[:bookingid]) end end end
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/titusfortner/ui2api.
History
While I've been leveraging this approach at my past few jobs, my solutions were application specific and <cough>
not
satisfyingly elegant. My initial attempts at implementing this gem were much too over-engineered and weren't solving
the actual general use case, so this project has stayed on the shelf in spite of the industry need for it.
Then at the 2017 Selenium Conference in Berlin, Mark Winteringham gave
a talk titled REST APIs and WebDriver: In Perfect Harmony.
This gave me the outside vantage point I needed to see how to focus the project. I started by copying the functionality
of the code in Mark's repo,
and then added in some extra goodness that leveraging WatirModel provides.
License
The gem is available as open source under the terms of the MIT License.