merge(

Close

Checks the indentation of the method name part in method calls that span more than one line.

Example: EnforcedStyle: aligned (default)

# bad
while myvariable
.b
  # do something
end

# good
while myvariable
      .b
  # do something
end

# good
Thing.a
     .b
     .c

Example: EnforcedStyle: indented

# good
while myvariable
  .b

  # do something
end

Example: EnforcedStyle: indentedrelativeto_receiver

# good
while myvariable
        .a
        .b

  # do something
end

# good
myvariable = Thing
               .a
               .b
               .c

        REGEX = /^[A-Za-z0-9_\.\-]+$/

Close

Checks for redundant escapes inside Regexp literals.

Example:

# bad
%r{foo\/bar}

# good
%r{foo/bar}

# good
/foo\/bar/

# good
%r/foo\/bar/

# good
%r!foo\!bar!

# bad
/a\-b/

# good
/a-b/

# bad
/[\+\-]\d/

# good
/[+\-]\d/

    DEFAULT_MANIFEST_PATH = File.expand_path("../../../config/engines.yml", __FILE__)

Close

Checks for use of the File.expand_path arguments. Likewise, it also checks for the Pathname.new argument.

Contrastive bad case and good case are alternately shown in the following examples.

Example:

# bad
File.expand_path('..', __FILE__)

# good
File.expand_path(__dir__)

# bad
File.expand_path('../..', __FILE__)

# good
File.expand_path('..', __dir__)

# bad
File.expand_path('.', __FILE__)

# good
File.expand_path(__FILE__)

# bad
Pathname(__FILE__).parent.expand_path

# good
Pathname(__dir__).expand_path

# bad
Pathname.new(__FILE__).parent.expand_path

# good
Pathname.new(__dir__).expand_path

        pattern.to_s.sub(%r{(/\*\*)?(/\*)?$}, "").sub(/^\!/, "")

Close

Checks for redundant escapes inside Regexp literals.

Example:

# bad
%r{foo\/bar}

# good
%r{foo/bar}

# good
/foo\/bar/

# good
%r/foo\/bar/

# good
%r!foo\!bar!

# bad
/a\-b/

# good
/a-b/

# bad
/[\+\-]\d/

# good
/[+\-]\d/

      def method_missing(*)
        yield if block_given?
      end

Close

Checks for the presence of method_missing without also defining respond_to_missing?.

Example:

#bad
def method_missing(name, *args)
  # ...
end

#good
def respond_to_missing?(name, include_private)
  # ...
end

def method_missing(name, *args)
  # ...
end

      class HTMLFormatter < Formatter # rubocop: disable Metrics/ClassLength

Close

Checks for comments put on the same line as some keywords. These keywords are: class, module, def, begin, end.

Note that some comments (:nodoc:, :yields:, rubocop:disable and rubocop:todo) are allowed.

Autocorrection removes comments from end keyword and keeps comments for class, module, def and begin above the keyword.

Safety:

Autocorrection is unsafe because it may remove a comment that is meaningful.

Example:

# bad
if condition
  statement
end # end if

# bad
class X # comment
  statement
end

# bad
def x; end # comment

# good
if condition
  statement
end

# good
class X # :nodoc:
  y
end

          name&.is_a?(String) && REGEX.match?(name)

Close

Checks for redundant safe navigation calls. instance_of?, kind_of?, is_a?, eql?, respond_to?, and equal? methods are checked by default. These are customizable with AllowedMethods option.

In the example below, the safe navigation operator (&.) is unnecessary because NilClass has methods like respond_to? and is_a?.

Safety:

This cop is unsafe, because autocorrection can change the return type of the expression. An offending expression that previously could return nil will be autocorrected to never return nil.

Example:

# bad
do_something if attrs&.respond_to?(:[])

# good
do_something if attrs.respond_to?(:[])

# bad
while node&.is_a?(BeginNode)
  node = node.parent
end

# good
while node.is_a?(BeginNode)
  node = node.parent
end

# good - without `&.` this will always return `true`
foo&.respond_to?(:to_a)

          config.engines.each { |e| e.enabled = false }

Close

Check for uses of braces or do/end around single line or multi-line blocks.

Methods that can be either procedural or functional and cannot be categorised from their usage alone is ignored. lambda, proc, and it are their defaults. Additional methods can be added to the IgnoredMethods.

Example: EnforcedStyle: linecountbased (default)

# bad - single line block
items.each do |item| item / 5 end

# good - single line block
items.each { |item| item / 5 }

# bad - multi-line block
things.map { |thing|
  something = thing.some_method
  process(something)
}

# good - multi-line block
things.map do |thing|
  something = thing.some_method
  process(something)
end

Example: EnforcedStyle: semantic

# Prefer `do...end` over `{...}` for procedural blocks.

# return value is used/assigned
# bad
foo = map do |x|
  x
end
puts (map do |x|
  x
end)

# return value is not used out of scope
# good
map do |x|
  x
end

# Prefer `{...}` over `do...end` for functional blocks.

# return value is not used out of scope
# bad
each { |x|
  x
}

# return value is used/assigned
# good
foo = map { |x|
  x
}
map { |x|
  x
}.inspect

# The AllowBracesOnProceduralOneLiners option is ignored unless the
# EnforcedStyle is set to `semantic`. If so:

# If the AllowBracesOnProceduralOneLiners option is unspecified, or
# set to `false` or any other falsey value, then semantic purity is
# maintained, so one-line procedural blocks must use do-end, not
# braces.

# bad
collection.each { |element| puts element }

# good
collection.each do |element| puts element end

# If the AllowBracesOnProceduralOneLiners option is set to `true`, or
# any other truthy value, then one-line procedural blocks may use
# either style. (There is no setting for requiring braces on them.)

# good
collection.each { |element| puts element }

# also good
collection.each do |element| puts element end

Example: EnforcedStyle: bracesforchaining

# bad
words.each do |word|
  word.flip.flop
end.join("-")

# good
words.each { |word|
  word.flip.flop
}.join("-")

Example: EnforcedStyle: always_braces

# bad
words.each do |word|
  word.flip.flop
end

# good
words.each { |word|
  word.flip.flop
}

Example: BracesRequiredMethods: ['sig']

# Methods listed in the BracesRequiredMethods list, such as 'sig'
# in this example, will require `{...}` braces. This option takes
# precedence over all other configurations except IgnoredMethods.

# bad
sig do
  params(
    foo: string,
  ).void
end
def bar(foo)
  puts foo
end

# good
sig {
  params(
    foo: string,
  ).void
}
def bar(foo)
  puts foo
end

Example: IgnoredMethods: ['lambda', 'proc', 'it' ] (default)

# good
foo = lambda do |x|
  puts "Hello, #{x}"
end

foo = lambda do |x|
  x * 100
end

          config: config,

Close

Checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

This cop has EnforcedShorthandSyntax option. It can enforce either the use of the explicit hash value syntax or the use of Ruby 3.1's hash value shorthand syntax.

The supported styles are:

• always - forces use of the 3.1 syntax (e.g. {foo:})
• never - forces use of explicit hash literal value
• either - accepts both shorthand and explicit use of hash literal value

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

Example: EnforcedShorthandSyntax: always (default)

# bad
{foo: foo, bar: bar}

# good
{foo:, bar:}

Example: EnforcedShorthandSyntax: never

# bad
{foo:, bar:}

# good
{foo: foo, bar: bar}

Example: EnforcedShorthandSyntax: either

# good
{foo: foo, bar: bar}

# good
{foo:, bar:}

          formatter: formatter,

Close

Checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

This cop has EnforcedShorthandSyntax option. It can enforce either the use of the explicit hash value syntax or the use of Ruby 3.1's hash value shorthand syntax.

The supported styles are:

• always - forces use of the 3.1 syntax (e.g. {foo:})
• never - forces use of explicit hash literal value
• either - accepts both shorthand and explicit use of hash literal value

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

Example: EnforcedShorthandSyntax: always (default)

# bad
{foo: foo, bar: bar}

# good
{foo:, bar:}

Example: EnforcedShorthandSyntax: never

# bad
{foo:, bar:}

# good
{foo: foo, bar: bar}

Example: EnforcedShorthandSyntax: either

# good
{foo: foo, bar: bar}

# good
{foo:, bar:}

        Array(@args[1..-1])

Close

Checks that arrays are sliced with endless ranges instead of ary[start..-1] on Ruby 2.6+.

Safety:

This cop is unsafe because x..-1 and x.. are only guaranteed to be equivalent for Array#[], and the cop cannot determine what class the receiver is.

For example: ruby sum = proc { |ary| ary.sum } sum[-3..-1] # => -6 sum[-3..] # Hangs forever

Example:

# bad
items[1..-1]

# good
items[1..]

          case arg
          when "--registry" then @registry_path = @args.shift
          when "--registry-prefix" then @registry_prefix = @args.shift
          end

Close

Checks for if expressions that do not have an else branch.

NOTE: Pattern matching is allowed to have no else branch because unlike if and case, it raises NoMatchingPatternError if the pattern doesn't match and without having else.

Supported styles are: if, case, both.

Example: EnforcedStyle: if

# warn when an `if` expression is missing an `else` branch.

# bad
if condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
case var
when condition
  statement
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

Example: EnforcedStyle: case

# warn when a `case` expression is missing an `else` branch.

# bad
case var
when condition
  statement
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
if condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

Example: EnforcedStyle: both (default)

# warn when an `if` or `case` expression is missing an `else` branch.

# bad
if condition
  statement
end

# bad
case var
when condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

            uri.query = { version: version, uid: global_config.uuid }.to_query

Close

Checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

This cop has EnforcedShorthandSyntax option. It can enforce either the use of the explicit hash value syntax or the use of Ruby 3.1's hash value shorthand syntax.

The supported styles are:

• always - forces use of the 3.1 syntax (e.g. {foo:})
• never - forces use of explicit hash literal value
• either - accepts both shorthand and explicit use of hash literal value

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

Example: EnforcedShorthandSyntax: always (default)

# bad
{foo: foo, bar: bar}

# good
{foo:, bar:}

Example: EnforcedShorthandSyntax: never

# bad
{foo:, bar:}

# good
{foo: foo, bar: bar}

Example: EnforcedShorthandSyntax: either

# good
{foo: foo, bar: bar}

# good
{foo:, bar:}

      def initialize(json = {})
        @config = json
      end

Close

Checks for the presence of constructors and lifecycle callbacks without calls to super.

This cop does not consider method_missing (and respond_to_missing?) because in some cases it makes sense to overtake what is considered a missing method. In other cases, the theoretical ideal handling could be challenging or verbose for no actual gain.

Example:

# bad
class Employee < Person
  def initialize(name, salary)
    @salary = salary
  end
end

# good
class Employee < Person
  def initialize(name, salary)
    super(name)
    @salary = salary
  end
end

# bad
class Parent
  def self.inherited(base)
    do_something
  end
end

# good
class Parent
  def self.inherited(base)
    super
    do_something
  end
end

  are currently installed, then installs any missing engines and checks for new images available for existing engines.

Close

MD013 - Line length

Tags: line_length

Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)

This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.

This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.

You also have the option to exclude this rule for code blocks and tables. To do this, set the code_blocks and/or tables parameters to false.

Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.

to facilitate that. Check the current VERSION (`cat VERSION`) and upgrade accordingly running:

Close

MD013 - Line length

Tags: line_length

Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)

This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.

This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.

You also have the option to exclude this rule for code blocks and tables. To do this, set the code_blocks and/or tables parameters to false.

Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.