Class: RuboCop::Cop::Style::BlockDelimiters

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::BlockDelimiters

Extended by:

AutoCorrector

Includes:

AllowedMethods, AllowedPattern, ConfigurableEnforcedStyle, RangeHelp

Defined in:

lib/rubocop/cop/style/block_delimiters.rb

Overview

Checks 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 AllowedMethods.

Examples:

EnforcedStyle: line_count_based (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

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 allowed 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

EnforcedStyle: braces_for_chaining

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

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

EnforcedStyle: always_braces

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

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

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 AllowedMethods.

# 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

AllowedMethods: [‘lambda’, ‘proc’, ‘it’ ] (default)

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

foo = lambda do |x|
  x * 100
end

AllowedPatterns: [] (default)

# bad
things.map { |thing|
  something = thing.some_method
  process(something)
}

AllowedPatterns: [‘map’]

# good
things.map { |thing|
  something = thing.some_method
  process(something)
}

Constant Summary

ALWAYS_BRACES_MESSAGE =

'Prefer `{...}` over `do...end` for blocks.'

BRACES_REQUIRED_MESSAGE =

"Brace delimiters `{...}` required for '%<method_name>s' method."

Constants included from RangeHelp

RangeHelp::BYTE_ORDER_MARK, RangeHelp::NOT_GIVEN

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary

• .autocorrect_incompatible_with ⇒ Object

Instance Method Summary

• #on_block(node) ⇒ Object (also: #on_numblock, #on_itblock)
• #on_send(node) ⇒ Object (also: #on_csend)

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, badge, #begin_investigation, callbacks_needed, #callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_gem_version, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Class Method Details

.autocorrect_incompatible_with ⇒ Object

# File 'lib/rubocop/cop/style/block_delimiters.rb', line 179

def self.autocorrect_incompatible_with
  [Style::RedundantBegin]
end

Instance Method Details

#on_block(node) ⇒ Object Also known as: on_numblock, on_itblock

# File 'lib/rubocop/cop/style/block_delimiters.rb', line 200

def on_block(node)
  return if part_of_ignored_node?(node)
  return if proper_block_style?(node)

  message = message(node)
  add_offense(node.loc.begin, message: message) do |corrector|
    autocorrect(corrector, node)
    ignore_node(node)
  end
end

#on_send(node) ⇒ Object Also known as: on_csend

# File 'lib/rubocop/cop/style/block_delimiters.rb', line 183

def on_send(node)
  return unless node.arguments?
  return if node.parenthesized?
  return if node.assignment_method?
  return if single_argument_operator_method?(node)

  node.arguments.each do |arg|
    get_blocks(arg) do |block|
      # If there are no parentheses around the arguments, then braces
      # and do-end have different meaning due to how they bind, so we
      # allow either.
      ignore_node(block)
    end
  end
end