starburstgem/starburst

This cop checks for redundant return expressions.

Example:

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

# bad
def test
  return something
end

# bad
def test
  one
  two
  three
  return something
end

# good
def test
  return something if something_else
end

# good
def test
  if x
  elsif y
  else
  end
end

Example: AllowMultipleReturnValues: false (default)

# bad
def test
  return x, y
end

Example: AllowMultipleReturnValues: true

# good
def test
  return x, y
end

This cop transforms usages of a method call safeguarded by a non nil check for the variable whose method is being called to safe navigation (&.). If there is a method chain, all of the methods in the chain need to be checked for safety, and all of the methods will need to be changed to use safe navigation. We have limited the cop to not register an offense for method chains that exceed 2 methods.

Configuration option: ConvertCodeThatCanStartToReturnNil The default for this is false. When configured to true, this will check for code in the format !foo.nil? && foo.bar. As it is written, the return of this code is limited to false and whatever the return of the method is. If this is converted to safe navigation, foo&.bar can start returning nil as well as what the method returns.

Example:

# bad
foo.bar if foo
foo.bar.baz if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo

foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?

foo && foo.bar
foo && foo.bar.baz
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }

# good
foo&.bar
foo&.bar&.baz
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo && foo.bar.baz.qux # method chain with more than 2 methods
foo && foo.nil? # method that `nil` responds to

# Method calls that do not use `.`
foo && foo < bar
foo < bar if foo

# This could start returning `nil` as well as the return of the method
foo.nil? || foo.bar
!foo || foo.bar

# Methods that are used on assignment, arithmetic operation or
# comparison should not be converted to use safe navigation
foo.baz = bar if foo
foo.baz + bar if foo
foo.bar > 2 if foo

Checks for if and unless statements that would fit on one line if written as modifier if/unless. The cop also checks for modifier if/unless lines that exceed the maximum line length.

The maximum line length is configured in the Layout/LineLength cop. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop.

Example:

# bad
if condition
  do_stuff(bar)
end

unless qux.empty?
  Foo.do_something
end

do_something_in_a_method_with_a_long_name(arg) if long_condition

# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?

if long_condition
  do_something_in_a_method_with_a_long_name(arg)
end

This cop is designed to help you transition from mutable string literals to frozen string literals. It will add the comment # frozen_string_literal: true to the top of files to enable frozen string literals. Frozen string literals may be default in future Ruby. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

Note that the cop will ignore files where the comment exists but is set to false instead of true.

Example: EnforcedStyle: always (default)

# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
  # ...
end

# good
# frozen_string_literal: true

module Bar
  # ...
end

# good
# frozen_string_literal: false

module Bar
  # ...
end

Example: EnforcedStyle: never

# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true

module Baz
  # ...
end

# good
module Baz
  # ...
end

Example: EnforcedStyle: always_true

# The `always_true` style enforces that the frozen string literal
# comment is set to `true`. This is a stricter option than `always`
# and forces projects to use frozen string literals.
# bad
# frozen_string_literal: false

module Baz
  # ...
end

# bad
module Baz
  # ...
end

# good
# frozen_string_literal: true

module Bar
  # ...
end

Checks if uses of quotes match the configured preference.

Example: EnforcedStyle: single_quotes (default)

# bad
"No special symbols"
"No string interpolation"
"Just text"

# good
'No special symbols'
'No string interpolation'
'Just text'
"Wait! What's #{this}!"

Example: EnforcedStyle: double_quotes

# bad
'Just some text'
'No special chars or interpolation'

# good
"Just some text"
"No special chars or interpolation"
"Every string in #{project} uses double_quotes"

This cop checks that the ABC size of methods is not higher than the configured maximum. The ABC size is based on assignments, branches (method calls), and conditions. See http://c2.com/cgi/wiki?AbcMetric and https://en.wikipedia.org/wiki/ABC_Software_Metric.

This cop 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

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}

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, constant definitions or constant visibility declarations.

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

module Math
end

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

# allowed
  # Class without body
  class Person
  end

  # Namespace - A namespace can be a class or a module
  # Containing a class
  module Namespace
    # Description/Explanation of Person class
    class Person
      # ...
    end
  end

  # Containing constant visibility declaration
  module Namespace
    class Private
    end

    private_constant :Private
  end

  # Containing constant definition
  module Namespace
    Public = Class.new
  end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks for indentation that doesn't use the specified number of spaces.

See also the IndentationConsistency cop which is the companion to this one.

Example:

# bad
class A
 def test
  puts 'hello'
 end
end

# good
class A
  def test
    puts 'hello'
  end
end

Example: IgnoredPatterns: ['^\s*module']

# bad
module A
class B
  def test
  puts 'hello'
  end
end
end

# good
module A
class B
  def test
    puts 'hello'
  end
end
end

This cop checks for indentation that doesn't use the specified number of spaces.

See also the IndentationConsistency cop which is the companion to this one.

Example:

# bad
class A
 def test
  puts 'hello'
 end
end

# good
class A
  def test
    puts 'hello'
  end
end

Example: IgnoredPatterns: ['^\s*module']

# bad
module A
class B
  def test
  puts 'hello'
  end
end
end

# good
module A
class B
  def test
    puts 'hello'
  end
end
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end

This cop checks for indentation that doesn't use the specified number of spaces.

See also the IndentationConsistency cop which is the companion to this one.

Example:

# bad
class A
 def test
  puts 'hello'
 end
end

# good
class A
  def test
    puts 'hello'
  end
end

Example: IgnoredPatterns: ['^\s*module']

# bad
module A
class B
  def test
  puts 'hello'
  end
end
end

# good
module A
class B
  def test
    puts 'hello'
  end
end
end

This cop checks that the indentation method is consistent. Either tabs only or spaces only are used for indentation.

Example: EnforcedStyle: spaces (default)

# bad
# This example uses a tab to indent bar.
def foo
  bar
end

# good
# This example uses spaces to indent bar.
def foo
  bar
end

Example: EnforcedStyle: tabs

# bad
# This example uses spaces to indent bar.
def foo
  bar
end

# good
# This example uses a tab to indent bar.
def foo
  bar
end