This cop checks if the length a class exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

This cop checks for uses of each_key and each_value Hash methods.

Note: If you have an array of two-element arrays, you can put parentheses around the block arguments to indicate that you're not working with a hash, and suppress RuboCop offenses.

Example:

# bad
hash.keys.each { |k| p k }
hash.values.each { |v| p v }
hash.each { |k, _v| p k }
hash.each { |_k, v| p v }

# good
hash.each_key { |k| p k }
hash.each_value { |v| p v }

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop can check for array literals made up of symbols that are not using the %i() syntax.

Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of3` will not enforce a style on an array of 2 or fewer elements.

Example: EnforcedStyle: percent (default)

# good
%i[foo bar baz]

# bad
[:foo, :bar, :baz]

Example: EnforcedStyle: brackets

# good
[:foo, :bar, :baz]

# bad
%i[foo bar baz]

This cop can check for array literals made up of symbols that are not using the %i() syntax.

Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of3` will not enforce a style on an array of 2 or fewer elements.

Example: EnforcedStyle: percent (default)

# good
%i[foo bar baz]

# bad
[:foo, :bar, :baz]

Example: EnforcedStyle: brackets

# good
[:foo, :bar, :baz]

# bad
%i[foo bar baz]

Checks for uses of if/unless modifiers with multiple-lines bodies.

Example:

# bad
{
  result: 'this should not happen'
} unless cond

# good
{ result: 'ok' } if cond

This cop checks for rescuing StandardError. There are two supported styles implicit and explicit. This cop will not register an offense if any error other than StandardError is specified.

Example: EnforcedStyle: implicit

# `implicit` will enforce using `rescue` instead of
# `rescue StandardError`.

# bad
begin
  foo
rescue StandardError
  bar
end

# good
begin
  foo
rescue
  bar
end

# good
begin
  foo
rescue OtherError
  bar
end

# good
begin
  foo
rescue StandardError, SecurityError
  bar
end

Example: EnforcedStyle: explicit (default)

# `explicit` will enforce using `rescue StandardError`
# instead of `rescue`.

# bad
begin
  foo
rescue
  bar
end

# good
begin
  foo
rescue StandardError
  bar
end

# good
begin
  foo
rescue OtherError
  bar
end

# good
begin
  foo
rescue StandardError, SecurityError
  bar
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop enforces consistent use of Object#is_a? or Object#kind_of?.

Example: EnforcedStyle: is_a? (default)

# bad
var.kind_of?(Date)
var.kind_of?(Integer)

# good
var.is_a?(Date)
var.is_a?(Integer)

Example: EnforcedStyle: kind_of?

# bad
var.is_a?(Time)
var.is_a?(String)

# good
var.kind_of?(Time)
var.kind_of?(String)

This cop can check for array literals made up of symbols that are not using the %i() syntax.

Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of3` will not enforce a style on an array of 2 or fewer elements.

Example: EnforcedStyle: percent (default)

# good
%i[foo bar baz]

# bad
[:foo, :bar, :baz]

Example: EnforcedStyle: brackets

# good
[:foo, :bar, :baz]

# bad
%i[foo bar baz]

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop checks for the formatting of empty method definitions. By default it enforces empty method definitions to go on a single line (compact style), but it can be configured to enforce the end to go on its own line (expanded style).

Note: A method definition is not considered empty if it contains comments.

Example: EnforcedStyle: compact (default)

# bad
def foo(bar)
end

def self.foo(bar)
end

# good
def foo(bar); end

def foo(bar)
  # baz
end

def self.foo(bar); end

Example: EnforcedStyle: expanded

# bad
def foo(bar); end

def self.foo(bar); end

# good
def foo(bar)
end

def self.foo(bar)
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop checks the indentation of the right hand side operand in binary operations that span more than one line.

Example:

# bad
if a +
b
  something
end

# good
if a +
   b
  something
end

This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.

The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.

Example:

# bad
class Person
  # ...
end

# good
# Description/Explanation of Person class
class Person
  # ...
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop can check for array literals made up of symbols that are not using the %i() syntax.

Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of3` will not enforce a style on an array of 2 or fewer elements.

Example: EnforcedStyle: percent (default)

# good
%i[foo bar baz]

# bad
[:foo, :bar, :baz]

Example: EnforcedStyle: brackets

# good
[:foo, :bar, :baz]

# bad
%i[foo bar baz]

This cop can check for array literals made up of symbols that are not using the %i() syntax.

Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of3` will not enforce a style on an array of 2 or fewer elements.

Example: EnforcedStyle: percent (default)

# good
%i[foo bar baz]

# bad
[:foo, :bar, :baz]

Example: EnforcedStyle: brackets

# good
[:foo, :bar, :baz]

# bad
%i[foo bar baz]

This cop enforces consistent use of Object#is_a? or Object#kind_of?.

Example: EnforcedStyle: is_a? (default)

# bad
var.kind_of?(Date)
var.kind_of?(Integer)

# good
var.is_a?(Date)
var.is_a?(Integer)

Example: EnforcedStyle: kind_of?

# bad
var.is_a?(Time)
var.is_a?(String)

# good
var.kind_of?(Time)
var.kind_of?(String)

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop checks for rescuing StandardError. There are two supported styles implicit and explicit. This cop will not register an offense if any error other than StandardError is specified.

Example: EnforcedStyle: implicit

# `implicit` will enforce using `rescue` instead of
# `rescue StandardError`.

# bad
begin
  foo
rescue StandardError
  bar
end

# good
begin
  foo
rescue
  bar
end

# good
begin
  foo
rescue OtherError
  bar
end

# good
begin
  foo
rescue StandardError, SecurityError
  bar
end

Example: EnforcedStyle: explicit (default)

# `explicit` will enforce using `rescue StandardError`
# instead of `rescue`.

# bad
begin
  foo
rescue
  bar
end

# good
begin
  foo
rescue StandardError
  bar
end

# good
begin
  foo
rescue OtherError
  bar
end

# good
begin
  foo
rescue StandardError, SecurityError
  bar
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop enforces the consistent usage of %-literal delimiters.

Specify the 'default' key to set all preferred delimiters at once. You can continue to specify individual preferred delimiters to override the default.

Example:

# Style/PercentLiteralDelimiters:
#   PreferredDelimiters:
#     default: '[]'
#     '%i':    '()'

# good
%w[alpha beta] + %i(gamma delta)

# bad
%W(alpha #{beta})

# bad
%I(alpha beta)

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop checks for redundant return expressions.

Example:

def test
  return something
end

def test
  one
  two
  three
  return something
end

It should be extended to handle methods whose body is if/else or a case expression with a default branch.

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cops checks for inconsistent indentation.

Example:

class A
  def test
    puts 'hello'
     puts 'world'
  end
end

This cop checks for braces around the last parameter in a method call if the last parameter is a hash. It supports braces, no_braces and context_dependent styles.

Example: EnforcedStyle: braces

# The `braces` style enforces braces around all method
# parameters that are hashes.

# bad
some_method(x, y, a: 1, b: 2)

# good
some_method(x, y, {a: 1, b: 2})

Example: EnforcedStyle: no_braces (default)

# The `no_braces` style checks that the last parameter doesn't
# have braces around it.

# bad
some_method(x, y, {a: 1, b: 2})

# good
some_method(x, y, a: 1, b: 2)

Example: EnforcedStyle: context_dependent

# The `context_dependent` style checks that the last parameter
# doesn't have braces around it, but requires braces if the
# second to last parameter is also a hash literal.

# bad
some_method(x, y, {a: 1, b: 2})
some_method(x, y, {a: 1, b: 2}, a: 1, b: 2)

# good
some_method(x, y, a: 1, b: 2)
some_method(x, y, {a: 1, b: 2}, {a: 1, b: 2})