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

Inherits:
Cop
  • Object
show all
Includes:
ConfigurableEnforcedStyle, IgnoredMethods
Defined in:
lib/rubocop/cop/style/block_delimiters.rb

Overview

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

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 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

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
}

Constant Summary collapse

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

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

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_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #disable_uncorrectable, #duplicate_location?, #excluded_file?, #external_dependency_checksum, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #messages, #parse, qualified_cop_name, #reason_to_not_correct, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_offense, #disable_uncorrectable?, #safe_autocorrect?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/block_delimiters.rb', line 136

def autocorrect(node)
  return if correction_would_break_code?(node)

  if node.braces?
    replace_braces_with_do_end(node.loc)
  else
    replace_do_end_with_braces(node.loc)
  end
end

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/block_delimiters.rb', line 130

def on_block(node)
  return if ignored_node?(node)

  add_offense(node, location: :begin) unless proper_block_style?(node)
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/block_delimiters.rb', line 115

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

  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