How to extend World in the context of cucumber-rails? - ruby-on-rails

I am building an API with Rails, using the rails-api gem. I want to use cucumber-rails and the gem 'Airborne' to test it.
Airborne comes with some nice helper methods for testing API responses, which I want to have access to in my step definitions. I have done this kind of thing before in Sinatra, which was relatively straightforward to configure in the /features/env.rb file.
It seems, however, that with rails-cucumber the creation of the 'World' happens behind the scenes somewhere and I don't know how to extend it to use the Airborne module after it's been created.
I have tried the following:
Airborne.configure do |config|
config.rack_app = Rails.application
end
Cucumber::Rails::World.extend(Airborne)
When(/^I make a request for information about an event$/) do
get "/events/1"
end
Then(/^I receive the information as a JSON$/) do
expect_json {}
end
I am still getting a NoMethodError on #expect_json, which is an Airborne method.
So my question is: how can I extend the instance of World in the context of cucumber-rails?

Don't panic, the World has been saved. The solution is to wrap Airborne and whatever else in a module:
module MyHelpers
include Airborne
include Capybara::DSL
end
Then pass that:
World(MyHelpers)

Related

Problem with constant autoloading in a Rails project (works occasionally)

I am working with a Rails project and don't quite understand how Rails autoloading works in my particular case. I read some articles about Rails' autoloading and its pitfalls but those didn't really help me
I am building a processor for tasks (exercises). Each task has its custom processor class in Tasks::<TaskName>::Processor that mixes in module Tasks::Processor that contain shared code for task processors. Processors contain class Get (for processing GET requests) located in Tasks::<TaskName>::Processor::Get that mixes in Tasks::Processor::Get containing generic Get's code.
I've simplified the code a little bit so it's easier to understand and removed all the business logic but it's still enough to reproduce the problem.
So the problem is:
when I run Tasks::TaskOne::Processor.new.get it works fine, but if I run Tasks::TaskTwo::Processor.new.get after that it throws an error: NoMethodError: undefined method `new' for Tasks::Processor::Get:Module. It also works the other way round: if I run TaskTwo's processor's code first then it works fine but the TaskOne's processor will throw the error. It just fails to find the specific implementation of Get and instead finds the generic module and tries to instantiate it which is obviously impossible.
Here is the code together with the structure.
Shared code:
app/models/tasks/processor.rb:
module Tasks
# generic Processor (mixed in by custom processors)
module Processor
# ...
end
end
app/models/tasks/processor/get.rb:
module Tasks
module Processor
# generic Get
module Get
# ...
end
end
end
TaskOne's code:
app/models/tasks/task_one/processor.rb:
module Tasks
module TaskOne
# processor for task_one
class Processor
include Tasks::Processor # mix in generic task processor
def get
Get.new.call
end
end
end
end
app/models/tasks/task_one/processor/get.rb:
module Tasks
module TaskOne
class Processor
# task_one's processor's custom Get
class Get
include Tasks::Processor::Get # mix in generic Get
def call
puts "in task_one's Processor's Get"
end
end
end
end
end
And practically identical code for the TaskTwo:
app/models/tasks/task_two/processor.rb:
module Tasks
module TaskTwo
# processor for task_two
class Processor
include Tasks::Processor # mix in generic task processor
def get
Get.new.call
end
end
end
end
app/models/tasks/task_two/processor/get.rb:
module Tasks
module TaskTwo
class Processor
# task_two's processor's custom Get
class Get
include Tasks::Processor::Get # mix in generic Get
def call
puts "in task_two's Processor's Get"
end
end
end
end
end
It has most likely something to do with Rails' autoloading, because when I use plain ruby and manually require all the files and try to run the code the problem doesn't happen.
Could you, please, explain why it works like this and tell me what the best way to avoid this problem is? Seems like Rails doesn't like the fact that I have a class and a module with same name and it gets confused, but I thought it shouldn't be a problem as they are in different namespaces.
I could have just named the generic class something different, but I'd really like to understand why using the same class name for both specific implementation and generic one only works for the first thing to load but not for the next. Thank you very much for your help!
P.S. my version of Ruby is 2.5.1 and Rails version is 5.2.1
I was literally reading about autoloading yesterday. Your problem is the same as the one outlined here:
https://guides.rubyonrails.org/autoloading_and_reloading_constants.html#when-constants-aren-t-missed
Basically, any time you write Get.new.call, you need to be more specific. It doesn’t know which Get to use in the tree of possible Gets. The first time you call it, it hasn’t had to load up more than one Get class, and so it actually finds the right one. After that call, you’ve now auto loaded MORE classes, and now things start to get dicey. You need to either qualify your Get to be more specific, and/or use require_dependency to force the right classes to be loaded in. However given your case, I think require_dependency will just make it fail every time, since you’ll now have all of the classes loaded up.

Where is a good place to initialize an API?

I wanted to use this api: https://github.com/coinbase/coinbase-ruby and the first step is to initialize the API, like this:
coinbase = Coinbase::Client.new(ENV['COINBASE_API_KEY'], ENV['COINBASE_API_SECRET'])
I was wondering what the best place to put this code is, and how would I access it if I put it "there"? I want this variable (coinbase) to be accessible ANYWHERE in the application.
Thanks!
The answer to this question really depends on your use case and your approach. My geral recommendation, however, is to create a Service Object (in the DDD sense) (see the section named "Domain Objects Should Not Know Anything About Infrastructure Underneath" in that link), that handles all communication with the Coinbase API. And then, within this service object, you can simply initialize the Coinbase::Client object once for however many times you call into it. Here's an example:
# app/services/coinbase_service.rb
class CoinbaseService
cattr_reader :coinbase_client, instance_accessor: false do
Coinbase::Client.new(ENV['COINBASE_API_KEY'], ENV['COINBASE_API_SECRET'])
end
def self.do_something
coinbase_client.do_something_in_their_api
end
def self.do_something_else
coinbase_client.do_something_else_in_their_api
end
end
So then you might do, e.g.:
# From MyController#action_1
if CoinbaseService.do_something
# ...
else
# ...
end
Or:
# From MyModel
def do_something
CoinbaseService.do_something_else
end
To get the service object working, you may need to add app/services to your autoload paths in application.rb file. I normally just add this:
# config/application.rb
config.autoload_paths += %W(#{config.root}/app)
I find this Service Object approach to be very beneficial organizationally, more efficient (only 1 invocation of the new Coinbase client needed), easier to test (easy to mock-out calls to Coinbase::Client), and simply joyful :).
One way to go about having a global variable can be done as similar as initializing redis in a Rails application by creating an initializer in config/initializers/coinbase.rb with:
$coinbase = Coinbase::Client.new(ENV['COINBASE_API_KEY'], ENV['COINBASE_API_SECRET'])
Now, you can access $coinbase anywhere in the application!
In the file config/initializers/coinbase.rb
Rails.application.config.after_initialize do
CoinbaseClient = Coinbase::Client.new(
Rails.application.credentials.coinbase[:api_key],
Rails.application.credentials.coinbase[:api_secret])
end
In place of the encrypted credentials, you could also use environment variables: ENV['COINBASE_API_KEY'], ENV['COINBASE_API_SECRET']
The above will make the constant CoinbaseClient available everywhere in your app. It will also ensure all your gems are loaded before the client is initialized.
Note: I am using Rails 6.1.4.4, and Ruby 2.7.5

Ruby MiniTest test design advice

I am testing http/https content for images that are on a web application running Rails 2.3. The layout is basic. I have my controllers with accompanying test directories including functional and integration folders with tests.
I'm still relatively new to Rails but I was wondering if there was a way to create a file that can test attachments across different controllers. For example, I need to test if whether the images on this web app are either http or https on the About/Projects/People/Accounts/ and Explore controllers. Instead of opening each of the about_controller_test, project_controller_test, etc. files writing the lines of code, I wanted to know if there was a way that I can make a master file that includes all of the controllers.
What I would like to do is to create some sort of module that I can include/extend the controllers in. This makes sense in my head but I run into the problem with naming conventions. If I wanted to make an attachments_test.rb, I wouldn't be able to do this because I don't have an attachments_controller.rb file that maps to it. How can I work around this?
All I would like is to make a file named along the lines of testing_attachment_protocols_test.rb which doesn't map to any controller but where I can put my tests in. I want to have one file to write my tests for different controllers instead of writing 1 test in several files. Would this file be included into test_helper.rb? Any help would be appreciated. Thanks.
---------EDIT-----------------------
I figured out the structure that I basically would like to implement for the test. Below is the general structure of the test that I would like to do.
require File.dirname(__FILE__) + '/../test_helper'
require 'open-uri'
def controller
......
end
class controller; def rescue_action(e) raise e end: end
class controller < Test::Unit::TestCase
def setup
#controller = controller
#request = ActionController::TestRequest.new
#response = ActionController::TestResponse.new
end
test "attachments url pattern for home page should include http when not logged in" do
setup
get :home
assert not_logged_in
#puts #response.body
assert_select("a img", :url =~ /sw.amazonaws/) do |anchor|
assert_equal 'http', anchor.protocol
end
end
end
Now the thing that I have trouble now is what to put in the method call for controller. My goal is to try to be as dynamic as possible. My goal is pretty much to create an attribute accessor method for different Controllers. Any thoughts?

How do I make functions in a gem available to Sinatra views?

The question here asks how to extract Rails view helper functions into a gem, and the accept answer is pretty good.
I am wondering - how to do the same for Sinatra? I'm making a gem that has a bunch of helper functions defined in a module, and I'd like to make these functions available to Sinatra views. But whatever I try, I cannot seem to access the functions, I just get a undefined local variable or method error.
So far, my gem structure looks like this (other stuff like gemspec omitted):
cool_gem/
lib/
cool_gem/
helper_functions.rb
sinatra.rb
cool_gem.rb
In cool_gem.rb, I have:
if defined?(Sinatra) and Sinatra.respond_to? :register
require 'cool_gem/sinatra'
end
In helper_functions.rb, I have:
module CoolGem
module HelperFunctions
def heading_tag(text)
"<h1>#{text}</h1>"
end
# + many more functions
end
end
In sinatra.rb, I have:
require 'cool_gem/helper_functions'
module CoolGem
module Sinatra
module MyHelpers
include CoolGem::HelperFunctions
end
def self.registered(app)
app.helpers MyHelpers
end
end
end
This doesn't work. Where am I going wrong?
(And in case you're wondering, yes, I need the helper functions in a separate file. I plan to make the gem compatible with Rails as well, so I want to keep the functions isolated/de-coupled if possible).
You’re mainly just missing the call to Sinatra.register (in cool_gem/sinatra.rb):
require 'sinatra/base'
require 'cool_gem/helper_functions'
module CoolGem
# you could just put this directly in the CoolGem module if you wanted,
# rather than have a Sinatra sub-module
module Sinatra
def self.registered(app)
#no need to create another module here
app.helpers CoolGem::HelperFunctions
end
end
end
# this is what you're missing:
Sinatra.register CoolGem::Sinatra
Now any classic style Sinatra app that requires cool_gem will have the helpers available. If you use the modular style you’ll also need to call register CoolGem::Sinatra inside the Sinatra::Base subclass.
In this case, if you are just providing some helper methods, an easier way might be to just use the helpers method (again in cool_gem/sinatra.rb):
require 'sinatra/base'
require 'cool_gem/helper_functions'
Sinatra.helpers CoolGem::HelperFunctions
Now the methods will be available in classic style apps, and modular style apps will need to call helpers CoolGem::HelperFunctions. This is a bit simpler, but if you are adding methods to the DSL context you will need to use registered as above.

How to stub in Rails development environment?

I'm looking for a reliable way to dynamically stub certain methods in my development environment. One example use case is when I need to do development that normally requires access to the Facebook Graph APIs but I don't have Internet access. I'd like to be able to stub the calls to fb_graph methods so it looks as if I'm authenticated and have profile data. Ideally I could turn the stubs on or off with a minor config change.
Any ideas? I'm assuming something like mocha can handle this?
You can use the VCR gem which will record the results of an initial HTTP request into a yml file and then use the contents of that yml file on subsequent http requests. It can then be configured to ignore the VCR logic and always make HTTP requests, if so desired:
https://www.relishapp.com/myronmarston/vcr
Mocha can certainly do it. But it feels a bit strange.
You could also do something like dependency injection.
For instance:
class User < AR::Base
def find_friends
Facebook.find_friends(facebook_id)
end
end
class Facebook
def self.find_friends(id)
# connect to Facebook here
end
end
class FakeFacebook
def self.find_friends(id)
# a fake implementation here
end
end
And inside an initializer:
if Rails.env.development?
User::Facebook = FakeFacebook
end

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