Class: RuboCop::Cop::Style::NumericPredicate

Inherits:

Cop

• Object
• Cop
• RuboCop::Cop::Style::NumericPredicate

Includes:

ConfigurableEnforcedStyle

Defined in:

lib/rubocop/cop/style/numeric_predicate.rb

Overview

This cop checks for usage of comparison operators (‘==`, `>`, `<`) to test numbers as zero, positive, or negative. These can be replaced by their respective predicate methods. The cop can also be configured to do the reverse.

The cop disregards ‘#nonzero?` as it its value is truthy or falsey, but not `true` and `false`, and thus not always interchangeable with `!= 0`.

The cop ignores comparisons to global variables, since they are often populated with objects which can be compared with integers, but are not themselves ‘Interger` polymorphic.

Examples:

# EnforcedStyle: predicate (default)

# bad

foo == 0
0 > foo
bar.baz > 0

# good

foo.zero?
foo.negative?
bar.baz.positive?

# EnforcedStyle: comparison

# bad

foo.zero?
foo.negative?
bar.baz.positive?

# good

foo == 0
0 > foo
bar.baz > 0

Constant Summary

MSG =

'Use `%s` instead of `%s`.'.freeze

REPLACEMENTS =

{
  'zero?' => '==',
  'positive?' => '>',
  'negative?' => '<'
}.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary

• #on_send(node) ⇒ Object

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, #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 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?, #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?, compatible_external_encoding_for?, directions, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_distance, line_range, move_pos, needs_escaping?, on_node, operator?, parentheses?, parenthesized_call?, preceed?, range_between, range_by_whole_lines, range_with_surrounding_comma, range_with_surrounding_space, same_line?, scrub_string, source_range, strip_quotes, stripped_source_upto, symbol_without_quote?, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, match_path?, relative_path, smart_path

Constructor Details

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

Instance Method Details

#on_send(node) ⇒ Object

# File 'lib/rubocop/cop/style/numeric_predicate.rb', line 61

def on_send(node)
  numeric, replacement = check(node)

  return unless numeric

  add_offense(node, :expression,
              format(MSG, replacement, node.source))
end