Setup Rspec, factory bot and database cleaner for Rails 5.2.6

Let’s find out how to configure a best test suite in Rails by using Rspec framwork and the other libraries that support rspec for writing smooth tests. We will be removing rails native test folder and other configurations.

For that we will be using Rspec, Factory bot for factories, Database cleaner.

Lets start from adding these gems into our Gemfile

group :development, :test do
  # Rspec testing module and needed libs
  gem 'factory_bot_rails', '5.2.0'
  gem 'rspec-rails', '~> 4.0.0'
end

group :test do
  # db cleaner for test suite 
  gem 'database_cleaner-active_record', '~> 2.0.1'
end

Now do

bunde install # this installs all the above gems

If you have already built the Rails app, your app may contain Rails own test suite. Remove the native rails test suite to add Rspec module to your project.

We use Rspec over rails native test module because rspec provides better helpers and machnism than Rails native test.

in application.rb file comment the following line

# require 'rails/test_unit/railtie'

inside the class Application add this line:

# Don't generate system test files.
config.generators.system_tests = nil

Remove the native rails test folder:

rm -r test/

We use factories over fixtures. Remove this line from rails_helper.rb

config.fixture_path = "#{::Rails.root}/spec/fixtures"

and modify this line to:

config.use_transactional_fixtures = false # instead of true

This is for preventing rails to generate the native test files when we run rails generators.

Database Cleaner

Now we configure the database cleaner that is used for managing data in our test cycles.

Open rails_helper.rb file and require that module

require 'rspec/rails'
require 'database_cleaner'  # <= add here

Note: Use only if you run integration tests with capybara or dealing with javascript codes in the test suite.

“Capybara spins up an instance of our Rails app that can’t see our test data transaction so even tho we’ve created a user in our tests, signing in will fail because to the Capybara run instance of our app, there are no users.”

I experienced database credentials issues:

➜ rspec
An error occurred while loading ./spec/models/user_spec.rb.
Failure/Error: ActiveRecord::Migration.maintain_test_schema!

Mysql2::Error::ConnectionError:
  Access denied for user 'username'@'localhost' (using password: NO)

First I thought of using database cleaner, later I realised that this error is because of my credentials.yml.enc file was corrupted somehow. I don’t know how that happend. So try to edit and see your credentials still exists in this file.

EDITOR="code --wait" bin/rails credentials:edit

Now in the Rspec configuration block we do the Database Cleaner configuration.

Add the following file:

spec/support/database_cleaner.rb

Inside, add the following:

# DB cleaner using database cleaner library
RSpec.configure do |config|
  # This says that before the entire test suite runs, clear 
  # the test database out completely
  config.before(:suite) do
    DatabaseCleaner.strategy = :transaction
    DatabaseCleaner.clean_with(:truncation)
  end

  # This sets the default database cleaning strategy to 
  # be transactions
  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  # include this if you uses capybara integration tests
  config.before(:each, :js => true) do
    DatabaseCleaner.strategy = :truncation
  end

  # These lines hook up database_cleaner around the beginning 
  # and end of each test, telling it to execute whatever 
  # cleanup strategy we selected
  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end
end

and be sure to require this file in rails_helper.rb

require 'rspec/rails'
require 'database_cleaner'
require_relative 'support/database_cleaner'  # <= here

Configure Factories

Note: We use factories over fixtures because factories provide better features that make writing test cases an easy task.

Create a folder to generate the factories:

mkdir spec/factories

Rails generators will automatically generate factory files for models inside this folder.

A generator for model automatically creating the following files:

spec/models/model_spec.rb
spec/factories/model.rb

Now lets load Factory bot configuration to rails test suite.

Add the following file:

spec/support/factory_bot.rb

and be sure to require this file in rails_helper.rb

require 'rspec/rails'
require 'database_cleaner'
require_relative 'support/database_cleaner'
require_relative 'support/factory_bot'  # <= here

You can see the following line commented

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

You can uncomment it to make all the factories available in your test suite. But I don’t recommend that to load all the files. We will be loading each factory whenver it is necessary.

Final rails_helper.rb file. We won’t use capybara for integration tests. So we are not adding database_cleaner configuration.

# 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__)
# Prevent database truncation if the environment is production
abort('The Rails environment is running in production mode!') if Rails.env.production?
require 'rspec/rails'
require_relative 'support/factory_bot'

# 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|
  # If you're not using ActiveRecord, or you'd prefer not to run each of your
  # examples within a transaction, remove the following line or assign false
  # instead of true.
  config.use_transactional_fixtures = false

  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")
end

A spec directory look something like this:

spec/
  controllers/
    user_controller_spec.rb
    product_controller_spec.rb
  factories/
    user.rb
    product.rb
  models/
    user_spec.rb
    product_spec.rb
  mailers/
    mailer_spec.rb
  services/
    service_spec.rb  
  rails_helper.rb
  spec_helper.rb

References:

https://github.com/rspec/rspec-rails
https://relishapp.com/rspec/rspec-rails/docs
https://github.com/thoughtbot/factory_bot/blob/master/GETTING_STARTED.md#configure-your-test-suite
https://github.com/DatabaseCleaner/database_cleaner

Model Specs

Lets generate a model spec. A model spec is used to test smaller parts of the system, such as classes or methods.

# RSpec also provides its own spec file generators
➜ rails generate rspec:model user
      create  spec/models/user_spec.rb
      invoke  factory_bot
      create    spec/factories/users.rb

Now run the rpsec command. That’s it. You can see the output from rspec.

➜ rspec
*

Pending: (Failures listed here are expected and do not affect your suite's status)

  1) Item add some examples to (or delete) /home/.../spec/models/user_spec.rb
     # Not yet implemented
     # ./spec/models/user_spec.rb:4

Finished in 0.00455 seconds (files took 1.06 seconds to load)
1 example, 0 failures, 1 pending

Lets discuss how to write a perfect model spec in the next lesson.

Rails 5.2.0 API Only application with latest Ruby 2.5.1

Check for the new ruby and rails versions
https://www.ruby-lang.org/en/downloads/
https://rubygems.org/gems/rails/versions

Here we are going to install Ruby – 2.5.1 & Rails – 5.2.0 (API only application)

Get rbenv into action
If you are not installed rbenv, you can install it from here:
https://github.com/rbenv/rbenv
After the installation make sure that, your $PATH has included rbenv/shims path. Else rbenv will not work.

1. $ rbenv install --list # Gets the list of ruby versions available

$ rbenv install 2.5.1

ruby-build: definition not found: 2.5.1

The following versions contain `2.5.1' in the name:
  rbx-2.5.1

See all available versions with `rbenv install --list'.

If the version you need is missing, try upgrading ruby-build:

  brew update && brew upgrade ruby-build

Oops..!

rbenv cannot find the version: 2.5.1

Upgrade ruby-build

Mac OSX:

$ brew upgrade ruby-build --HEAD

Now install ruby 2.5.1

$ rbenv install 2.5.1

Create a new gemset:

Rbenv gemset is a separate script and not coming with rbenv. If you are not installed this, you can install it from here:
https://github.com/jf/rbenv-gemset

$ rbenv gemset create 2.5.1 demo-app
That set up a directory for you in ~/.rbenv/versions/2.5.1/gemsets/demo-app

Set the ruby version to the newest

$ rbenv local 2.5.1

$ rbenv version
=> 2.5.1

    Activate New Gemset


For activating a gemset we need to create a .rbenv-gemsets file in the current directory.

$ touch .rbenv-gemsets
$ echo demo-app > .rbenv-gemsets

Check active gemset:

$ rbenv gemset active

Install Rails 5.2.0 API only Application

$ gem install rails -v '5.2.0'

$ rails -v
Rails 5.2.0

Later we can delete this .rbenv-gemsets file and add a new file named ‘.ruby-gemset’ in the rails project directory. I cannot find any other option for doing this. If anyone know more about this, please give a comment. I appreciate that.

Create a New Rails app

$ rails new demo-app  --api -T # API only skip the testing framework altogether

For Full Rails:

$ rails new demo-app -T -d postgresql # skip the testing framework altogether, uses Postgres Database

-T to exclude Minitest – the default testing framework if you are planning to use RSpec to test your API.

Rspec test framework:
https://github.com/rspec/rspec-rails

You can use the following with Rspec.
Shoulda Matchers:
Collection of testing matchers extracted from Shoulda (http://matchers.shoulda.io)
https://github.com/thoughtbot/shoulda-matchers

Database Cleaner:
Strategies for cleaning databases in Ruby. Can be used to ensure a clean state for testing
https://github.com/DatabaseCleaner/database_cleaner

Faker:
A library for generating fake data such as names, addresses, and phone numbers.
https://github.com/stympy/faker

use option: –no-rdoc –no-ri # skips the documentation

Remove Rbenv Gemset and add Ruby gems file

$ rm .rbenv-gemsets

$ cd demo-app
$ touch .ruby-gemset
$ echo demo-app > .ruby-gemset
$ rails s
=> Booting Puma
=> Rails 5.2.0 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.11.4 (ruby 2.5.1-p57), codename: Love Song
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop

Goto http://localhost:3000/

rails-5.2.api-application

Done! Lets go…

#Rails 4.2: How to create a full URL with given host and port

Basically if you need to generate url based on the current url during a request OR you can create your own Urls by using Rails ‘ActionDispatch::Integration::Session‘ class.

Rails creates an object ‘app’. It is and action dispatch session object.

You can make use of that object for creating your own URLs like:

> app.root_url(:port => 20)  => "http://www.example.com:20/"

> app.root_url(:port => 20, :host => 'www.bing.com')
 => "http://www.bing.com:20/"

During a request you can use like this:

 > request.url(:port => 20)

How to send Basic Authentication (BA) credentials in ruby on rails

HTTP Basic authentication is a simple authentication scheme in which user authentication is done by a username and password eliminating the needs of cookies, sessions and login pages. It is base64 encoded.

Rails provides a method for this type of authentication: authenticate_with_http_basic

This method can be used as follows:

authenticate_with_http_basic do |username, password|
  ——
end

Inside the block you can access the username and password.

But how to send a request with basic auth in rails ?

This is really tricky and I didn’t find any documentation for this. Here I am describing how to send a request with basic auth.

1. Use Faraday library (Faraday is an HTTP client lib)
https://github.com/lostisland/faraday

Create a connection:

connection = Faraday.new(:url => HOST) do |faraday|
      faraday.request  :url_encoded             # form-encode POST params
      faraday.response :logger                  # log requests to STDOUT
      faraday.adapter  Faraday.default_adapter  # make requests with Net::HTTP
      faraday.basic_auth(USERNAME, PASSWORD)
end

parameters = params[‘user’].permit!.to_h

response = connection.get do |req|
      req.url(params[:url])
      req.headers['Content-Type'] = 'application/json'
      req.params.merge!(parameters)
end

response = connection.post do |req|
        req.url(params[:url])
        req.headers['Content-Type'] = 'application/json'
        req.body = parameters
end

render json: response.body

Here,

HOST = 'http://lvh.me:3002'
USERNAME = 'EdcddzrbmET55016'
PASSWORD = 'UXBJnS309S49st3rHqmH5934'
params['url'] = '/users/profile'

We can use Faraday’s (‘faraday.basic_auth’) basic auth method to reach out our solution.

If you are getting any error like follows in post request

NoMethodError (undefined method `bytesize' for {}:ActiveSupport::HashWithIndifferentAccess):

Don’t forget to convert the ruby hash ‘parameters’ to json by calling ‘to_json’ upon it.

        req.body = parameters.to_json 

In Other way you can use something like this to generate the basic auth header

request.env['HTTP_AUTHORIZATION'] = ActionController::HttpAuthentication::Basic.encode_credentials(USERNAME, PASSWORD)

How to use Ruby Rest Client:

require 'rest_client'

headers = {
  :authorization => 'Basic FytxhZGKpbjpvcGVuIHNlc2FtHUHU'
}

response = RestClient.get 'https://yourdomain.com/api/users.json?activityId=02ddf868-6484-440f-8c39-c7d4fb4e7b33', headers
puts response

Rbenv: Start with new ruby and rails versions

Check for the new ruby and rails versions
https://www.ruby-lang.org/en/downloads/
https://rubygems.org/gems/rails/versions

Here we are going to install Ruby – 2.4.1 & Rails – 5.1.3

Get rbenv into action
If you are not installed rbenv, you can install it from here:
https://github.com/rbenv/rbenv
After the installation make sure that, your $PATH has included rbenv/shims path. Else rbenv will not work.

1. $ rbenv install --list # Gets the list of ruby versions available

$ rbenv install 2.4.1

ruby-build: definition not found: 2.4.1

The following versions contain `2.4.1' in the name:
  rbx-2.4.1

See all available versions with `rbenv install --list'.

If the version you need is missing, try upgrading ruby-build:

  brew update && brew upgrade ruby-build

Oops..!

rbenv cannot find the version: 2.4.1

Upgrade ruby-build

Mac OSX:

$ brew upgrade ruby-build --HEAD

Now install ruby 2.4.1

$ rbenv install 2.4.1

Create a new gemset:

Rbenv gemset is a separate script and not coming with rbenv. If you are not installed this, you can install it from here:
https://github.com/jf/rbenv-gemset

$ rbenv gemset create 2.4.1 demo-app
That set up a directory for you in ~/.rbenv/versions/2.4.1/gemsets/demo-app

Set the ruby version to the newest

$ rbenv local 2.4.1

$ rbenv version
=> 2.4.1

    Activate New Gemset


For activating a gemset we need to create a .rbenv-gemsets file in the current directory.

$ touch .rbenv-gemsets
$ echo demo-app > .rbenv-gemsets

Check active gemset:

$ rbenv gemset active

Install Rails 5.1.3

$ gem install rails -v '5.1.3'
$ gem install --no-rdoc --no-ri rails -v '5.1.3' # skips the documentation

Later we can delete this .rbenv-gemsets file and add a new file named ‘.ruby-gemset’ in the rails project directory. I cannot find any other option for doing this. If anyone know more about this, please give a comment. I appreciate that.

Create a New Rails app

$ rails new demo-app

$ rm .rbenv-gemsets

$ cd demo-app
$ touch .ruby-gemset
$ echo demo-app > .ruby-gemset
$ touch .ruby-version
$ echo 2.4.1 > .ruby-version
$ rails s
=> Booting Puma
=> Rails 5.1.3 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.9.1 (ruby 2.4.1-p111), codename: Private Caller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop

Goto http://localhost:3000/

rails-5-new.png

Done! Lets go…

#Rails 4.2 #Ruby2.2 How to find association class and other info from an object and its association name

When I was doing a Rails project, I encountered one situation like: I need the association class of an association object. I have the object and its association name as input. How can I find the association class?

Suppose we have Student class that belongs to a school

class School
  has_many students
end

class Student
  belongs_to :school
end

and suppose so many other relations like this in our project.

So we have

s = Student.last
:school symbol 

I can use

s.school.class and s.school.class.name

But what if the school is blank? The result is ‘NilClass’ From the above code.

Basically for has_many associations now we get the class name as

"ActiveRecord::Associations::CollectionProxy"

because recently in new rails version a change of the Array of objects as associations to its own ‘CollectionProxy’ collections.

So we can use ‘ActiveRecord::Reflection::ClassMethods’ for finding all the association info.

Note that this Rails module is so useful to find all the association related information.

In the above situation we can use ‘reflect_on_association’ method for finding association reflection info. And it returns ‘ActiveRecord::Reflection’ Object.

http://api.rubyonrails.org/classes/ActiveRecord/Reflection/ClassMethods.html#method-i-reflect_on_association

Check the following code:

> s.class.reflect_on_association(:school)
=> ##}, @scope_lock=#
, @class_name="Topic", @foreign_key="school_id">

Set up capistrano deployment for Ruby On Rails

STEP 1:
Install capistrano gem

group :test, :development do
  gem 'capistrano'
end

Install capistrano with rvm

gem 'rvm-capistrano'

STEP 2:
Prepare your Project for Capistrano
Capify your project. The following command initialise your project with Capistrano.

$ capify .

STEP 3:
Do proper modificatons in Capistrano Recipe (config/deploy.rb)
http://guides.beanstalkapp.com/deployments/deploy-with-capistrano.html

Lets do the deployment for staging environment.
Create a ruby file under config/deploy/ folder named staging.rb
Copy the following content

set :domain, "mydomain.in"
role :app, domain
role :web, domain
role :db, domain, :primary => true
role :resque_worker, domain   # if you are using workers in your project, set role for them if needed
role :resque_scheduler, domain # if you are using workers in your project

set :deploy_to, "/home/my_deploy_path/"  # the deployment directory
set :environment, "staging"
set :rails_env, "staging"
set :branch, "staging"
set :previous_environment, "develop"

STEP 4:
Setup capistrano in deployment server

$ cap staging deploy:setup

This will Create folder structure that capistrano uses in the process.

Make sure that everything is set up correctly on the server by the command

$ cap staging deploy:check

Now you can see a message like:
“You appear to have all necessary dependencies installed”

Create shared/config folder in your deploy_to path
and copy database.yml and other config files as you written in the symlink_shared task in cap recipie (if any)

STEP 5:
Deploy your project:

cap staging deploy

How to categorise a blog posts data by month in Ruby On Rails

Suppose we have created a ‘BlogPost’ Model in Rails and it have the following fields in a blog post:

title – title of the blog post
posted_on – date posted
permalink – a permanent link of each blog post (act as a primary key)
publish – a boolean field which decides the post need to show or not

Lets write a method in ‘BlogPost’ Model to get a recent list of posts.
Pass a ‘months_old’ parameter to determine how much months old posts we wanted to list.
Just select the required columns to show the details of the post (by ‘:select => ‘). And Group each post by posted month.

  def self.get_recent_months_post(months_old)
    @blog_posts = where("publish = ? AND posted_on > ?", true, Date.today - months_old.months).all(:select => "title, posted_on, permalink", :order => "posted_on DESC")
    (@blog_posts.group_by { |t| t.posted_on.beginning_of_month }).sort.reverse
  end

We successfully written the method above. Now lets write a method to get the archives (old posts).

  def self.get_archives(old)
    @blog_posts = where("publish = ? AND posted_on  "title, posted_on, permalink", :order => "posted_on DESC")
    (@blog_posts.group_by { |t| t.posted_on.beginning_of_month }).sort.reverse
  end

How to create a migration file dynamically by meta programming in rails 4.0

If you want to create a migration file from a module written in lib file or somewhere from your ruby file and execute it, use the metaprogramming which can create a class or method dynamically. The following code snippet shows the methods we use and gives a better idea to create migration file dynamically.

def create_columns(tb_with_cols)
    add_columns = ""
    tb_name = tb_with_cols.keys.first
    columns = tb_with_cols.values.first
    columns.each { |c_name, c_type| add_columns << "\tadd_column(':#{tb_name}', :#{c_name}, :#{c_type})\n" }

    add_columns
 end

 def migration_file_content(tb_with_cols)
   cols = create_columns(tb_with_cols)
<<-RUBY
  class AddMissingColumnsToTable < ActiveRecord::Migration
     def change_table
    #{cols}
   end
 end
  RUBY
 end


 def write_content_to_file(path, content)
    File.open(path, 'w+') do |f|
      f.write(content)
    end
 end

Just call the method migration_file_content in your code. Pass the parameter tb_with_cols as a Hash, in which the key is the table_name and value is the columns that should be added to that table. Ex:

tb_with_cols = {:users => {:name => :string, :age => :integer, :address => :text} }
content = migration_file_content(tb_with_cols)
write_content_to_file("#{Rails.root}/db/migrations/', content)

After that call the method write_content_to_file with your new migration file path and the content from our migration_file_content method. 🙂

Rails way of creating a new full url with new parameters after removing old parameters from a url

If we have some keys and values and we just need to create a url with this data just pass the url and hash as a parameter to the following method.

def generate_url_with_params(url, params = {})
    uri = URI(url)
    uri.query = params.to_query
    uri.to_s
end

If you want to get rid of the parameters from a url use the following method.

  def generate_url_without_params(url, params = {})
    uri = URI(url)
    full_params = Rack::Utils.parse_query uri.query
    params.each do |key, val|
      full_params.delete key
    end
    uri.query = full_params.to_param
    uri.to_s
  end