Add explanations to cops

.rubocop.yml

@@ -24,6 +24,7 @@ AllCops:
     - 'bin/**/*'
     - 'generator_templates/**/*'
 
+# Gems in consecutive lines should be alphabetically sorted
 Bundler/OrderedGems:
   Enabled: false
 
@@ -50,6 +51,8 @@ Style/AlignArray:
 Style/AlignHash:
   Enabled: true
 
+# Here we check if the parameters on a multi-line method call or
+# definition are aligned.
 Style/AlignParameters:
   Enabled: false
 
@@ -74,6 +77,7 @@ Style/AsciiIdentifiers:
 Style/Attr:
   Enabled: true
 
+# This cop checks if usage of %() or %Q() matches configuration.
 Style/BarePercentLiterals:
   Enabled: true
 
@@ -94,9 +98,12 @@ Style/BlockDelimiters:
 Style/BlockEndNewline:
   Enabled: true
 
+ # This cop checks for braces around the last parameter in a method call
+# if the last parameter is a hash.
 Style/BracesAroundHashParameters:
   Enabled: false
 
+# This cop checks for uses of the case equality operator(===).
 Style/CaseEquality:
   Enabled: false
 
@@ -128,9 +135,13 @@ Style/ClassMethods:
 Style/ClassVars:
   Enabled: true
 
+# This cop checks for methods invoked via the :: operator instead
+# of the . operator (like FileUtils::rmdir instead of FileUtils.rmdir).
 Style/ColonMethodCall:
   Enabled: true
 
+# This cop checks that comment annotation keywords are written according
+# to guidelines.
 Style/CommentAnnotation:
   Enabled: false
 
@@ -138,6 +149,9 @@ Style/CommentAnnotation:
 Style/CommentIndentation:
   Enabled: true
 
+# Check for `if` and `case` statements where each branch is used for
+# assignment to the same variable when using the return of the
+# condition can be used instead.
 Style/ConditionalAssignment:
   Enabled: true
 
@@ -153,10 +167,14 @@ Style/DefWithParentheses:
 Style/Documentation:
   Enabled: false
 
+# This cop checks the . position in multi-line method calls.
 Style/DotPosition:
   Enabled: true
   EnforcedStyle: leading
 
+# This cop checks for uses of double negation (!!) to convert something
+# to a boolean value. As this is both cryptic and usually redundant, it
+# should be avoided.
 Style/DoubleNegation:
   Enabled: false
 
@@ -332,6 +350,8 @@ Style/MultilineOperationIndentation:
 Style/MultilineTernaryOperator:
   Enabled: true
 
+# This cop checks whether some constant value isn't a
+# mutable literal (e.g. array or hash).
 Style/MutableConstant:
   Enabled: true
 
@@ -437,6 +457,7 @@ Style/SpaceBeforeComment:
 Style/SpaceBeforeSemicolon:
   Enabled: true
 
+# Checks for spaces inside square brackets.
 Style/SpaceInsideBrackets:
   Enabled: true
 
@@ -476,6 +497,7 @@ Style/Tab:
 Style/TrailingBlankLines:
   Enabled: true
 
+# This cop checks for trailing comma in array and hash literals.
 Style/TrailingCommaInLiteral:
   Enabled: false
 
@@ -524,6 +546,7 @@ Metrics/AbcSize:
   Enabled: true
   Max: 60
 
+# This cop checks if the length of a block exceeds some maximum value.
 Metrics/BlockLength:
   Enabled: false
 
@@ -571,9 +594,13 @@ Metrics/PerceivedComplexity:
 Lint/AmbiguousOperator:
   Enabled: true
 
+# This cop checks for ambiguous regexp literals in the first argument of
+# a method invocation without parentheses.
 Lint/AmbiguousRegexpLiteral:
   Enabled: false
 
+# This cop checks for assignments in the conditions of
+# if/while/until.
 Lint/AssignmentInCondition:
   Enabled: false
 
@@ -638,6 +665,7 @@ Lint/FloatOutOfRange:
 Lint/FormatParameterMismatch:
   Enabled: true
 
+# This cop checks for *rescue* blocks with no body.
 Lint/HandleExceptions:
   Enabled: false
 
@@ -664,6 +692,7 @@ Lint/LiteralInCondition:
 Lint/LiteralInInterpolation:
   Enabled: true
 
+# This cop checks for uses of *begin...end while/until something*.
 Lint/Loop:
   Enabled: false
 
@@ -696,6 +725,8 @@ Lint/RescueException:
 Lint/ShadowedException:
   Enabled: false
 
+# This cop looks for use of the same name as outer local variables
+# for block arguments or block local variables.
 Lint/ShadowingOuterLocalVariable:
   Enabled: false
 
@@ -707,6 +738,7 @@ Lint/StringConversionInInterpolation:
 Lint/UnderscorePrefixedVariableName:
   Enabled: true
 
+# This cop checks for using Fixnum or Bignum constant
 Lint/UnifiedInteger:
   Enabled: true
 
@@ -716,6 +748,7 @@ Lint/UnifiedInteger:
 Lint/UnneededDisable:
   Enabled: false
 
+# This cop checks for unneeded usages of splat expansion
 Lint/UnneededSplatExpansion:
   Enabled: false
 
@@ -723,9 +756,11 @@ Lint/UnneededSplatExpansion:
 Lint/UnreachableCode:
   Enabled: true
 
+# This cop checks for unused block arguments.
 Lint/UnusedBlockArgument:
   Enabled: false
 
+# This cop checks for unused method arguments.
 Lint/UnusedMethodArgument:
   Enabled: false
 
@@ -772,12 +807,18 @@ Performance/LstripRstrip:
 Performance/RangeInclude:
   Enabled: true
 
+# This cop identifies the use of a `&block` parameter and `block.call`
+# where `yield` would do just as well.
 Performance/RedundantBlockCall:
   Enabled: true
 
+# This cop identifies use of `Regexp#match` or `String#match in a context
+# where the integral return value of `=~` would do just as well.
 Performance/RedundantMatch:
   Enabled: true
 
+# This cop identifies places where `Hash#merge!` can be replaced by
+# `Hash#[]=`.
 Performance/RedundantMerge:
   Enabled: true
   MaxKeyValuePairs: 1
@@ -803,6 +844,8 @@ Performance/TimesMap:
 
 # Security ####################################################################
 
+# This cop checks for the use of JSON class methods which have potential
+# security issues.
 Security/JSONLoad:
   Enabled: true
 
@@ -830,9 +873,11 @@ Rails/Date:
 Rails/Delegate:
   Enabled: true
 
+# This cop checks dynamic `find_by_*` methods.
 Rails/DynamicFindBy:
   Enabled: false
 
+# This cop enforces that 'exit' calls are not used within a rails app.
 Rails/Exit:
   Enabled: true
   Exclude:
@@ -851,6 +896,9 @@ Rails/FindEach:
 Rails/HasAndBelongsToMany:
   Enabled: true
 
+# This cop is used to identify usages of http methods like `get`, `post`,
+# `put`, `patch` without the usage of keyword arguments in your tests and
+# change them to use keyword args.
 Rails/HttpPositionalArguments:
   Enabled: false
 
@@ -863,6 +911,8 @@ Rails/Output:
     - 'lib/backup/**/*'
     - 'lib/tasks/**/*'
 
+# This cop checks for the use of output safety calls like html_safe and
+# raw.
 Rails/OutputSafety:
   Enabled: false
 
@@ -878,9 +928,11 @@ Rails/ReadWriteAttribute:
 Rails/ScopeArgs:
   Enabled: true
 
+# This cop checks for the use of Time methods without zone.
 Rails/TimeZone:
   Enabled: false
 
+# This cop checks for the use of old-style attribute validation macros.
 Rails/Validation:
   Enabled: true
 
@@ -941,15 +993,19 @@ RSpec/Focus:
 RSpec/InstanceVariable:
   Enabled: false
 
+# Checks for `subject` definitions that come after `let` definitions.
 RSpec/LeadingSubject:
   Enabled: false
 
+# Checks unreferenced `let!` calls being used for test setup.
 RSpec/LetSetup:
   Enabled: false
 
+# Check that chains of messages are not being stubbed.
 RSpec/MessageChain:
   Enabled: false
 
+# Checks that message expectations are set using spies.
 RSpec/MessageSpies:
   Enabled: false
 
@@ -957,12 +1013,15 @@ RSpec/MessageSpies:
 RSpec/MultipleDescribes:
   Enabled: false
 
+# Checks if examples contain too many `expect` calls.
 RSpec/MultipleExpectations:
   Enabled: false
 
+# Checks for explicitly referenced test subjects.
 RSpec/NamedSubject:
   Enabled: false
 
+# Checks for nested example groups.
 RSpec/NestedGroups:
   Enabled: false
 
@@ -971,9 +1030,11 @@ RSpec/NotToNot:
   EnforcedStyle: not_to
   Enabled: true
 
+# Check for repeated description strings in example groups.
 RSpec/RepeatedDescription:
   Enabled: false
 
+# Checks for stubbed test subjects.
 RSpec/SubjectStub:
   Enabled: false