Guard Demo

• Steps to Build the Guard Demo

  • 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://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://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://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