Class: RuboCop::Cop::Style::GuardClause

Inherits:
Cop
  • Object
show all
Includes:
ConfigurableEnforcedStyle, IfNode, MinBodyLength
Defined in:
lib/rubocop/cop/style/guard_clause.rb

Overview

Use a guard clause instead of wrapping the code inside a conditional expression

Examples:

# bad
def test
  if something
    work
  end
end

# good
def test
  return unless something
  work
end

# also good
def test
  work if something
end

# bad
if something
  raise 'exception'
else
  ok
end

# good
raise 'exception' if something
ok

Constant Summary collapse

MSG = 
'Use a guard clause instead of wrapping the code inside a ' \
'conditional expression.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES, Util::STRING_ESCAPES, Util::STRING_ESCAPE_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from MinBodyLength

#min_body_length, #min_body_length?

Methods included from IfNode

#if_else?, #if_node_parts, #modifier_if?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #parameter_name, #style, #style_detected, #supported_styles, #unexpected_style_detected

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search_body

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?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, ternary_op?, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, hidden?, issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#on_def(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/guard_clause.rb', line 51

def on_def(node)
  _, _, body = *node
  return unless body

  if if?(body)
    check_trailing_if(body)
  elsif body.begin_type?
    last_expr = body.children.last
    check_trailing_if(last_expr) if if?(last_expr)
  end
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/guard_clause.rb', line 63

def on_if(node)
  cond, body, else_body = *node

  return unless body && else_body
  # discard modifier ifs and ternary_ops
  return if modifier_if?(node) || ternary_op?(node) || elsif?(node)

  return unless single_line_control_flow_exit?(body) ||
                single_line_control_flow_exit?(else_body)
  return if cond.multiline?
  return if line_too_long_when_corrected?(node)

  add_offense(node, :keyword, MSG)
end