1 files changed, 226 insertions, 0 deletions
diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000000..ce0b95ddd4
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,226 @@
+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:
+    - '**/templates/**/*'
+    - '**/vendor/**/*'
+    - 'actionpack/lib/action_dispatch/journey/parser.rb'
+    - 'railties/test/fixtures/tmp/**/*'
+    - 'actionmailbox/test/dummy/**/*'
+    - 'node_modules/**/*'
+
+Performance:
+  Exclude:
+    - '**/test/**/*'
+
+Rails:
+  Enabled: true
+
+# Prefer assert_not over assert !
+Rails/AssertNot:
+  Include:
+    - '**/test/**/*'
+
+# Prefer assert_not_x over refute_x
+Rails/RefuteMethods:
+  Include:
+    - '**/test/**/*'
+
+# Prefer &&/|| over and/or.
+Style/AndOr:
+  Enabled: true
+
+# Do not use braces for hash literals when they are the last argument of a
+# method call.
+Style/BracesAroundHashParameters:
+  Enabled: true
+  EnforcedStyle: context_dependent
+
+# Align `when` with `case`.
+Layout/CaseIndentation:
+  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/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
+
+Layout/FirstParameterIndentation:
+  Enabled: true
+
+# Use Ruby >= 1.9 syntax for hashes. Prefer { a: :b } over { :a => :b }.
+Style/HashSyntax:
+  Enabled: true
+
+# Method definitions after `private` or `protected` isolated calls need one
+# extra level of indentation.
+Layout/IndentationConsistency:
+  Enabled: true
+  EnforcedStyle: rails
+
+# 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/SpaceAroundOperators:
+  Enabled: true
+
+Layout/SpaceBeforeComma:
+  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'
+    - 'actionmailbox/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/Tab:
+  Enabled: true
+
+# Blank lines should not have any spaces.
+Layout/TrailingBlankLines:
+  Enabled: true
+
+# No trailing whitespace.
+Layout/TrailingWhitespace:
+  Enabled: true
+
+# Use quotes for string literals when they are enough.
+Style/UnneededPercentQ:
+  Enabled: true
+
+# Use my_method(my_arg) not my_method( my_arg ) or my_method my_arg.
+Lint/RequireParentheses:
+  Enabled: true
+
+Lint/StringConversionInInterpolation:
+  Enabled: true
+
+Lint/UriEscapeUnescape:
+  Enabled: true
+
+Style/ParenthesesAroundCondition:
+  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/UnfreezeString:
+  Enabled: true