Create App

rails new guard_demo --database=postgresql --skip-test-unit;
cd guard_demo;

Install RSpec for Rails

echo 'gem "rspec-rails", :group => [:development, :test]' >> Gemfile;
bundle install;
rails generate rspec:install;

Install Dependencies

bundle install

Run Server

rails s

Add Static Pages

• Link: https://www.railstutorial.org/book/static_pages
• Generate Controller

  rails g controller StaticPages home help
  

• Update Routes

  root to: 'static_pages#home'
  get 'static_pages/home', to: 'static_pages#home'
  get 'static_pages/help', to: 'static_pages#help'
  

Run PostgreSQL

Create and migrate DB

rails db:create db:migrate

Run Tests

bundle exec rspec

Add Guard RSpec

• Reference: https://github.com/guard/guard-rspec
• Add Guard RSpec to Gemfile

  group :development, :test do
    gem 'guard-rspec'
  end
  

• Install dependency

  bundle install
  

• Generate RSpec files

  bundle exec guard init rspec
  

• Run Guard

  bundle exec guard
  

• Run Rails Server in a separate Tab

  rails s
  

• Change a Unit Test to see the Guard Terminal window auto-run the Unit tests and fail
  • Change in spec/controllers/static_pages_controller_spec.rb
    • Before

      expect(response).to have_http_status(:success)
      

    • After

      expect(response).to have_http_status(404)
      

    • Result - Terminal displays test failure

      expected the response to have status code 404 but it was 200
      

  • Reference: https://github.com/rspec/rspec-rails/blob/master/lib/rspec/rails/matchers/have_http_status.rb

Add LiveReload - automatically reload after views modified

• Reference:

  • http:https://livereload.com/
  • https://github.com/guard/guard-livereload

• Add Ruby version to Gemfile

  source 'https://rubygems.org'
  ruby '2.4.2'
  

• Add Guard LiveReload to Gemfile

  group :development, :test do
    gem 'guard-livereload', '~> 2.5', require: false
  end
  

• Install dependencies

  bundle install
  

• Generate LiveReload config files

  bundle exec guard init livereload
  

• Install LiveReload browser extension (see guard-livereload Gem Readme and Wiki on Github)

  • Browser Extension - http:https://livereload.com/extensions/#installing-sections

• Switch to Ruby version

  rbenv global 2.4.2
  rbenv shell 2.4.2
  

• Overcome Errors - encountered errors and mitigation measures

  • Problem 1 - Error when running rails s

    Could not find eventmachine-1.2.5 in any of the sources
    Run `bundle install` to install missing gems.
    

  • Solution 1 - Change Gemfile to the following

    group :development, :test do
      gem 'eventmachine', '1.2.5',
        path: 'vendor/bundle/gems/eventmachine-1.2.5',
        require: 'eventmachine'
      # http:https://railscasts.com/episodes/264-guard
      gem 'rb-fsevent', :require => false if RUBY_PLATFORM =~ /darwin/i
      gem 'guard-rspec', '~> 4.7.3'
      gem 'guard-livereload', '~> 2.5.2'
    end
    

    • Update Gemfile.lock

      bundle update
      

  • Problen 2 - Error still when running rails s

    ~/guard_demo/vendor/bundle/gems/pg-0.21.0/lib/pg.rb:4:in `require': dlopen(~/guard_demo/vendor/bundle/gems/pg-0.21.0/lib/pg_ext.bundle, 9): Symbol not found: _rb_cFixnum (LoadError)
    

  • Solution - Switch from PostgreSQL 0.21.0 to 0.20.0 by changing Gemfile to the following:

    gem 'pg', '0.20',
      path: 'vendor/bundle/gems/pg-0.20.0',
      require: 'pg'
    

    • Update Gemfile.lock

      bundle update
      

  • Problem 3 - Error when trying to run Guard or Rails Server

    $ bundle exec guard
    
    21:55:09 - ERROR - Invalid Guardfile, original error is:
    > [#]
    > [#] incompatible library version - ~/guard_demo/vendor/bundle/gems/http_parser.rb-0.6.0/lib/ruby_http_parser.bundle,
    

    $ rails s
    Could not find http_parser.rb-0.5.3 in any of the sources
    Run `bundle install` to install missing gems.
    

  • Solution - Change Gemfile to from version 0.6.0 of http_parser.rb Gem to 0.5.3

    group :development, :test do
      gem 'http_parser.rb', '0.5.3'
    end
    

    • Update Gems

    bundle update
    

• Open two Terminal Tabs and run the following

  • In Tab 1 - rails s
  • In Tab 2 - bundle exec guard

• Edit code in Rails views and see each changes automatically reflected in Browser and Unit Tests run upon each change (no need to refresh the browser manually, or to manually run RSpec after each code change)

• The above issues encountered during installation of Guard-LiveReload have been reported here - guard/guard-livereload#177