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Class: RuboCop::Cop::Style::MinMaxComparison

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/min_max_comparison.rb

Overview

Enforces the use of max or min instead of comparison for greater or less.

Note
It can be used if you want to present limit or threshold in Ruby 2.7+. That it is slow though. So autocorrection will apply generic max or min:
a.clamp(b..) # Same as `[a, b].max`
a.clamp(..b) # Same as `[a, b].min`

Examples:

# bad
a > b ? a : b
a >= b ? a : b

# good
[a, b].max

# bad
a < b ? a : b
a <= b ? a : b

# good
[a, b].min

Cop Safety Information:

  • This cop is unsafe because even if a value has < or > method, it is not necessarily Comparable.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

.builtin?

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Cops (other than builtin) are encouraged to implement this.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::RangeHelp - Included

#add_range, #column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.

#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.

#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect,
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range, #reset_investigation, #use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#autocorrect(corrector, node, replacement) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/min_max_comparison.rb', line 72

def autocorrect(corrector, node, replacement)
  if node.elsif?
    corrector.remove(range_between(node.parent.loc.else.begin_pos, node.loc.else.begin_pos))
    corrector.replace(node.else_branch, replacement)
  else
    corrector.replace(node, replacement)
  end
end

#on_if(node)

[ GitHub ]

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

def on_if(node)
  lhs, operator, rhs = *node.condition
  return unless COMPARISON_OPERATORS.include?(operator)

  if_branch = node.if_branch
  else_branch = node.else_branch
  preferred_method = preferred_method(operator, lhs, rhs, if_branch, else_branch)
  return unless preferred_method

  replacement = "[#{lhs.source}, #{rhs.source}].#{preferred_method}"

  add_offense(node, message: format(MSG, prefer: replacement)) do |corrector|
    autocorrect(corrector, node, replacement)
  end
end

#preferred_method(operator, lhs, rhs, if_branch, else_branch) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/min_max_comparison.rb', line 64

def preferred_method(operator, lhs, rhs, if_branch, else_branch)
  if lhs == if_branch && rhs == else_branch
    GRATER_OPERATORS.include?(operator) ? 'max' : 'min'
  elsif lhs == else_branch && rhs == if_branch
    LESS_OPERATORS.include?(operator) ? 'max' : 'min'
  end
end