Ruby設定3　Rubocop

# RuboCop

## PATH
```console
(m・_・bp) 18:16 ~/Desktop/vsnote2.0/ruby/lib/rubybook_2 % which rubocop
/Users/uekiyoshihiro/.rbenv/shims/rubocop

```
## RuboCopの導入
[ruby\-style\-guide/README\.ja\.md at japanese · fortissimo1997/ruby\-style\-guide](https://github.com/fortissimo1997/ruby-style-guide/blob/japanese/README.ja.md)

```console
# グローバルインストール
$ gem install rubocop

# インストール確認
$ rubocop -v

# インストール場所確認
$ which rubocop
/Users/myname/.rbenv/shims/rubocop
```

## Rubocopの使用とオプション
```console
$ rubocop

# 自動修正(--auto-correctでもOK)
$ rubocop -a

# 違反した項目をすべて無効とする設定ファイル（.rubocop_todo.yml）が生成される やらなくてもいいかな
$ rubocop --auto-gen-config
```

## Railsの設定に対応する
### Gemのインストール
```console
$ cd <プロジェクトルート> #プロジェクトルートに移動
$ gem install rubocop-performance #2つをインストール
$ gem install rubocop-rails
```
### 設定ファイルを新しく作成する
```console
$ cd <プロジェクトルート> #プロジェクトルートに移動
$ touch .rubocop.yml  #設定ファイルを新規作成
$ curl https://raw.githubusercontent.com/rails/rails/master/.rubocop.yml > .rubocop.yml #rails本家のコード規約をダウンロードして.rubocop.ymlファイルへ出力
```

## .rubocop.ymlの中身
```console
require:
  - rubocop-performance
  - rubocop-rails

AllCops:
  TargetRubyVersion: 2.5
  # RuboCop has a bunch of cops enabled by default. This setting tells RuboCop
  # to ignore them, so only the ones explicitly set in this file are enabled.
  DisabledByDefault: true
  Exclude:
    - '**/tmp/**/*'
    - '**/templates/**/*'
    - '**/vendor/**/*'
    - 'actionpack/lib/action_dispatch/journey/parser.rb'
    - 'railties/test/fixtures/tmp/**/*'
    - 'actionmailbox/test/dummy/**/*'
    - 'actiontext/test/dummy/**/*'
    - '**/node_modules/**/*'

Performance:
  Exclude:
    - '**/test/**/*'

# Prefer assert_not over assert !
Rails/AssertNot:
  Include:
    - '**/test/**/*'

# Prefer assert_not_x over refute_x
Rails/RefuteMethods:
  Include:
    - '**/test/**/*'

Rails/IndexBy:
  Enabled: true

Rails/IndexWith:
  Enabled: true

# Prefer &&/|| over and/or.
Style/AndOr:
  Enabled: true

# Align `when` with `case`.
Layout/CaseIndentation:
  Enabled: true

Layout/ClosingHeredocIndentation:
  Enabled: true

# Align comments with method definitions.
Layout/CommentIndentation:
  Enabled: true

Layout/ElseAlignment:
  Enabled: true

# Align `end` with the matching keyword or starting expression except for
# assignments, where it should be aligned with the LHS.
Layout/EndAlignment:
  Enabled: true
  EnforcedStyleAlignWith: variable
  AutoCorrect: true

Layout/EmptyLineAfterMagicComment:
  Enabled: true

Layout/EmptyLinesAroundAccessModifier:
  Enabled: true
  EnforcedStyle: only_before

Layout/EmptyLinesAroundBlockBody:
  Enabled: true

# In a regular class definition, no empty lines around the body.
Layout/EmptyLinesAroundClassBody:
  Enabled: true

# In a regular method definition, no empty lines around the body.
Layout/EmptyLinesAroundMethodBody:
  Enabled: true

# In a regular module definition, no empty lines around the body.
Layout/EmptyLinesAroundModuleBody:
  Enabled: true

# Use Ruby >= 1.9 syntax for hashes. Prefer { a: :b } over { :a => :b }.
Style/HashSyntax:
  Enabled: true

Layout/FirstArgumentIndentation:
  Enabled: true

# Method definitions after `private` or `protected` isolated calls need one
# extra level of indentation.
Layout/IndentationConsistency:
  Enabled: true
  EnforcedStyle: indented_internal_methods

# Two spaces, no tabs (for indentation).
Layout/IndentationWidth:
  Enabled: true

Layout/LeadingCommentSpace:
  Enabled: true

Layout/SpaceAfterColon:
  Enabled: true

Layout/SpaceAfterComma:
  Enabled: true

Layout/SpaceAfterSemicolon:
  Enabled: true

Layout/SpaceAroundEqualsInParameterDefault:
  Enabled: true

Layout/SpaceAroundKeyword:
  Enabled: true

Layout/SpaceBeforeComma:
  Enabled: true

Layout/SpaceBeforeComment:
  Enabled: true

Layout/SpaceBeforeFirstArg:
  Enabled: true

Style/DefWithParentheses:
  Enabled: true

# Defining a method with parameters needs parentheses.
Style/MethodDefParentheses:
  Enabled: true

Style/FrozenStringLiteralComment:
  Enabled: true
  EnforcedStyle: always
  Exclude:
    - 'actionview/test/**/*.builder'
    - 'actionview/test/**/*.ruby'
    - 'actionpack/test/**/*.builder'
    - 'actionpack/test/**/*.ruby'
    - 'activestorage/db/migrate/**/*.rb'
    - 'activestorage/db/update_migrate/**/*.rb'
    - 'actionmailbox/db/migrate/**/*.rb'
    - 'actiontext/db/migrate/**/*.rb'

Style/RedundantFreeze:
  Enabled: true

# Use `foo {}` not `foo{}`.
Layout/SpaceBeforeBlockBraces:
  Enabled: true

# Use `foo { bar }` not `foo {bar}`.
Layout/SpaceInsideBlockBraces:
  Enabled: true
  EnforcedStyleForEmptyBraces: space

# Use `{ a: 1 }` not `{a:1}`.
Layout/SpaceInsideHashLiteralBraces:
  Enabled: true

Layout/SpaceInsideParens:
  Enabled: true

# Check quotes usage according to lint rule below.
Style/StringLiterals:
  Enabled: true
  EnforcedStyle: double_quotes

# Detect hard tabs, no hard tabs.
Layout/IndentationStyle:
  Enabled: true

# Empty lines should not have any spaces.
Layout/TrailingEmptyLines:
  Enabled: true

# No trailing whitespace.
Layout/TrailingWhitespace:
  Enabled: true

# Use quotes for string literals when they are enough.
Style/RedundantPercentQ:
  Enabled: true

Lint/AmbiguousOperator:
  Enabled: true

Lint/AmbiguousRegexpLiteral:
  Enabled: true

Lint/ErbNewArguments:
  Enabled: true

# Use my_method(my_arg) not my_method( my_arg ) or my_method my_arg.
Lint/RequireParentheses:
  Enabled: true

Lint/ShadowingOuterLocalVariable:
  Enabled: true

Lint/RedundantStringCoercion:
  Enabled: true

Lint/UriEscapeUnescape:
  Enabled: true

Lint/UselessAssignment:
  Enabled: true

Lint/DeprecatedClassMethods:
  Enabled: true

Style/ParenthesesAroundCondition:
  Enabled: true

Style/HashTransformKeys:
  Enabled: true

Style/HashTransformValues:
  Enabled: true

Style/RedundantBegin:
  Enabled: true

Style/RedundantReturn:
  Enabled: true
  AllowMultipleReturnValues: true

Style/Semicolon:
  Enabled: true
  AllowAsExpressionSeparator: true

# Prefer Foo.method over Foo::method
Style/ColonMethodCall:
  Enabled: true

Style/TrivialAccessors:
  Enabled: true

Performance/FlatMap:
  Enabled: true

Performance/RedundantMerge:
  Enabled: true

Performance/StartWith:
  Enabled: true

Performance/EndWith:
  Enabled: true

Performance/RegexpMatch:
  Enabled: true

Performance/ReverseEach:
  Enabled: true

Performance/UnfreezeString:
  Enabled: true

Performance/DeletePrefix:
  Enabled: true

Performance/DeleteSuffix:
  Enabled: true

```




## githooksの設定
[【Ruby on Rails】rubocop と pre\-commit を利用して git commit 時にコーディングチェックを行う \- きゃまなかのブログ](https://techblog.kyamanak.com/entry/2018/06/19/221910)