# bad# Expect extend be before constantclassPerson<ApplicationRecordhas_many:ordersANSWER=42extendSomeModuleincludeAnotherModuleend# goodclassPerson# extend and include go firstextendSomeModuleincludeAnotherModule# inner classesCustomError=Class.new(StandardError)# constants are nextSOME_CONSTANT=20# afterwards we have public attribute macrosattr_reader:name# followed by other macros (if any)validates:name# then we have public delegate macrosdelegate:to_s,to: :name# public class methods are next in linedefself.some_methodend# initialization goes between class methods and instance methodsdefinitializeend# followed by other public instance methodsdefsome_methodend# protected attribute macros and methods go nextprotectedattr_reader:protected_namedefsome_protected_methodend# private attribute macros, delegate macros and methods# are grouped near the endprivateattr_reader:private_namedelegate:some_private_delegate,to: :namedefsome_private_methodendend
# badfoo(<<-SQL
bar
SQL)foo(<<-SQL,123,<<-NOSQL,
bar
SQL
baz
NOSQL)foo(bar(<<-SQL
baz
SQL),123,)# goodfoo(<<-SQL)
bar
SQLfoo(<<-SQL,123,<<-NOSQL)
bar
SQL
baz
NOSQLfoo(bar(<<-SQL),
baz
SQL123,)
irb(main):001:0>"hoge".to_i=>0irb(main):002:0>Integer("hoge",10)Traceback (most recent call last):
5: from /usr/local/bin/irb:23:in `<main>' 4: from /usr/local/bin/irb:23:in `load'
3: from /usr/local/lib/ruby/gems/2.6.0/gems/irb-1.0.0/exe/irb:11:in `<top (required)>' 2: from (irb):2
1: from (irb):2:in `Integer'
ArgumentError (invalid value for Integer(): "hoge")
一貫して DateTime ではなく Time を使うように推奨しているが、
複数のタイムゾーンやサマータイムを扱ったりするときなど、
特別なケースでは二つは代替可能なものではないのでデフォルトで Disabled になっているらしい。
# bad - uses `DateTime` for current timeDateTime.now# good - uses `Time` for current timeTime.now# bad - uses `DateTime` for modern dateDateTime.iso8601('2016-06-29')# good - uses `Time` for modern dateTime.iso8601('2016-06-29')# good - uses `DateTime` with start argument for historical dateDateTime.iso8601('1751-04-23',Date::ENGLAND)
# badarray.deletee# goodarray.delete(e)# good# Operators don't need parensfoo==bar# good# Setter methods don't need parensfoo.bar=baz# okay with `puts` listed in `IgnoredMethods`puts'test'# okay with `^assert` listed in `IgnoredPatterns`assert_equal'test',x
if , case に対して、 else が存在しないと警告してくれる。 if だけ、 case だけ、という設定も可能。
# warn when an `if` or `case` expression is missing an `else` branch.# badifconditionstatementend# badcasevarwhenconditionstatementend# goodifconditionstatementelse# the content of `else` branch will be determined by Style/EmptyElseend# goodcasevarwhenconditionstatementelse# the content of `else` branch will be determined by Style/EmptyElseend
認定によりRubyベースでシステム開発を行ううえで必要な基礎的な知識と応用力をもつことをアピールすることができます。試験の合格者は、Rubyアソシエーションにより「 Ruby Association Certified Ruby Programmer Silver/Gold version 2.1」として認定されます。
$ rails g migration ChangeHogesNameNotNull
Running via Spring preloader in process 6959
invoke active_record
create db/migrate/xxxxxxxxxxx_change_hoges_name_not_null.rb
class CreateProducts < ActiveRecord::Migration[6.0]
def change
create_table :products do |t|
t.string :name
t.integer :price
t.timestamps
end
end
end
class CreateCarts < ActiveRecord::Migration[6.0]
def change
create_table :carts do |t|
t.timestamps
end
end
end
class CreateCartItems < ActiveRecord::Migration[6.0]
def change
create_table :cart_items do |t|
t.integer :quantity, default: 0
t.references :product, null: false, foreign_key: true
t.references :cart, null: false, foreign_key: true
t.timestamps
end
end
end
class Product < ApplicationRecord
end
class Cart < ApplicationRecord
has_many :cart_items
end
class CartItem < ApplicationRecord
belongs_to :product
belongs_to :cart
end
The dependency tzinfo-data (>= 0) will be unused by any of the platforms Bundler is installing for. Bundler is installing for ruby but the dependency is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those platforms to the bundle, run `bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java`.
The purpose of this line is to include the tzinfo-data gem in the bundle on Windows to act as a source of time zone data. This gem is unnecessary on Ubuntu (and Unix-based systems in general) because the system includes time zone data that can be read directly by tzinfo.
