Class: RuboCop::Cop::Style::TrailingCommaInBlockArgs

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/trailing_comma_in_block_args.rb

Overview

This cop checks whether trailing commas in block arguments are required. Blocks with only one argument and a trailing comma require that comma to be present. Blocks with more than one argument never require a trailing comma.

add do |foo, bar,|
  foo + bar
 end

# good
add do |foo, bar|
  foo + bar
end

# good
 add do |foo,|
  foo
end

# good
add do
   foo + bar
end

Examples:

# bad
add { |foo, bar,| foo + bar }

 # good
add { |foo, bar| foo + bar }

# good
add { |foo,| foo }

# good
add { foo }

# bad

Constant Summary collapse

MSG = 
'Useless trailing comma present in block arguments.'

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

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?, #message, #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/trailing_comma_in_block_args.rb', line 55

def autocorrect(node)
  ->(corrector) { corrector.replace(last_comma(node).pos, '') }
end

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/trailing_comma_in_block_args.rb', line 46

def on_block(node)
  # lambda literal (`->`) never has block arguments.
  return if node.send_node.lambda_literal?

  return unless useless_trailing_comma?(node)

  add_offense(node, location: last_comma(node).pos)
end