Class: RuboCop::Cop::Lint::Void

Inherits:

Cop

• Object
• Cop
• RuboCop::Cop::Lint::Void

Defined in:

lib/rubocop/cop/lint/void.rb

Overview

This cop checks for operators, variables, literals, and nonmutating methods used in void context.

Examples:

# bad

def some_method
  some_num * 10
  do_something
end

# bad

def some_method(some_var)
  some_var
  do_something
end

# bad, when CheckForMethodsWithNoSideEffects is set true

def some_method(some_array)
  some_array.sort
  do_something(some_array)
end

# good

def some_method
  do_something
  some_num * 10
end

# good

def some_method(some_var)
  do_something
  some_var
end

# good, when CheckForMethodsWithNoSideEffects is set true

def some_method(some_array)
  some_array.sort!
  do_something(some_array)
end

Constant Summary

OP_MSG =

'Operator `%<op>s` used in void context.'

VAR_MSG =

'Variable `%<var>s` used in void context.'

LIT_MSG =

'Literal `%<lit>s` used in void context.'

SELF_MSG =

'`self` used in void context.'

DEFINED_MSG =

'`%<defined>s` used in void context.'

NONMUTATING_MSG =

'Method `#%<method>s` used in void context. ' \
'Did you mean `#%<method>s!`?'

BINARY_OPERATORS =

%i[* / % + - == === != < > <= >= <=>].freeze

UNARY_OPERATORS =

%i[+@ -@ ~ !].freeze

OPERATORS =

(BINARY_OPERATORS + UNARY_OPERATORS).freeze

VOID_CONTEXT_TYPES =

%i[def for block].freeze

NONMUTATING_METHODS =

%i[capitalize chomp chop collect compact
delete_prefix delete_suffix downcase
encode flatten gsub lstrip map next reject
reverse rotate rstrip scrub select shuffle
slice sort sort_by squeeze strip sub succ
swapcase tr tr_s transform_values
unicode_normalize uniq upcase].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary

• #on_begin(node) ⇒ Object (also: #on_kwbegin)
• #on_block(node) ⇒ Object

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, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

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 AST::Sexp

#s

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #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

#on_begin(node) ⇒ Object Also known as: on_kwbegin

# File 'lib/rubocop/cop/lint/void.rb', line 90

def on_begin(node)
  check_begin(node)
end

#on_block(node) ⇒ Object

# File 'lib/rubocop/cop/lint/void.rb', line 83

def on_block(node)
  return unless node.body && !node.body.begin_type?
  return unless in_void_context?(node.body)

  check_expression(node.body)
end