Rails

Application

rails new my_app --database=postgresql # create app
rails s # start
rails s -p 1234 # start with port 1234
rails c # console 
rake -T # list task

Scaffold

rails g scaffold product name:string price:decimal{7,2}

Check on Heroku Reserved Words before naming

Migration

rake db:drop
rake db:create
rake db:migrate
rake db:rollback
RAILS_ENV=test rake db:drop

Add column

rails g migration add_email_to_users email:string

Common Migration datatype

:binary
:boolean
:date
:datetime
:decimal
:float
:integer
:bigint
:primary_key
:string
:text
:time
:timestamp

Postgres specific datatype

Rspec

rspec
rspec spec/models/user.spec.rb
rspec spec/models/user.spec.rb:43

Spec for ‘belong to’

assc = described_class.reflect_on_association(:user_group)
expect(assc.macro).to eq :belongs_to

Spec for presence of

group = FactoryBot.build(:application_group, name: '')
expect(template).to_not be_valid

Rake Task

Create rake task with argument

task :task1 => [:environment] do
  puts ENV['path']
end

task :task2 => [:environment] do
  puts ARGV[1]
end

task :task3, [:message] => :environment do |t, args|
  args.with_defaults(:path => "default")
  puts args.path
end

rake task1 path="your path"
rake task2 "your_path"
rake "task3[your_path]"