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Class: RuboCop::Cop::Style::FloatDivision

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/float_division.rb

Overview

Checks for division with integers coerced to floats. It is recommended to either always use fdiv or coerce one side only. This cop also provides other options for code consistency.

Examples:

EnforcedStyle: single_coerce (default)

# bad
a.to_f / b.to_f

# good
a.to_f / b
a / b.to_f

EnforcedStyle: left_coerce

# bad
a / b.to_f
a.to_f / b.to_f

# good
a.to_f / b

EnforcedStyle: right_coerce

# bad
a.to_f / b
a.to_f / b.to_f

# good
a / b.to_f

EnforcedStyle: fdiv

# bad
a / b.to_f
a.to_f / b
a.to_f / b.to_f

# good
a.fdiv(b)

Cop Safety Information:

  • This cop is unsafe, because if the operand variable is a string object then .to_f will be removed and an error will occur.

    a = '1.2'
    b = '3.4'
    a.to_f / b.to_f # Both `to_f` calls are required here

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

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.

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

Returns an url to view this cops documentation online.

.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::ConfigurableEnforcedStyle - Included

::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

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#add_to_f_method(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 121

def add_to_f_method(corrector, node)
  corrector.insert_after(node, '.to_f') unless node.send_type? && node.method?(:to_f)
end

#any_coerce?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 79

def_node_matcher :any_coerce?, <<~PATTERN
  {(send _ :/ (send _ :to_f)) (send (send _ :to_f) :/ _)}
PATTERN

#both_coerce?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 75

def_node_matcher :both_coerce?, <<~PATTERN
  (send (send _ :to_f) :/ (send _ :to_f))
PATTERN

#correct_from_slash_to_fdiv(corrector, node, receiver, argument) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 130

def correct_from_slash_to_fdiv(corrector, node, receiver, argument)
  receiver_source = extract_receiver_source(receiver)
  argument_source = extract_receiver_source(argument)

  if argument.respond_to?(:parenthesized?) && !argument.parenthesized?
    argument_source = "(#{argument_source})"
  end

  corrector.replace(node, "#{receiver_source}.fdiv#{argument_source}")
end

#extract_receiver_source(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 141

def extract_receiver_source(node)
  if node.send_type? && node.method?(:to_f)
    node.receiver.source
  else
    node.source
  end
end

#left_coerce?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 71

def_node_matcher :left_coerce?, <<~PATTERN
  (send (send _ :to_f) :/ _)
PATTERN

#message(_node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 117

def message(_node)
  MESSAGES[style]
end

#offense_condition?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 102

def offense_condition?(node)
  case style
  when :left_coerce
    right_coerce?(node)
  when :right_coerce
    left_coerce?(node)
  when :single_coerce
    both_coerce?(node)
  when :fdiv
    any_coerce?(node)
  else
    false
  end
end

#on_send(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 83

def on_send(node)
  return unless offense_condition?(node)

  add_offense(node) do |corrector|
    case style
    when :left_coerce, :single_coerce
      add_to_f_method(corrector, node.receiver)
      remove_to_f_method(corrector, node.first_argument)
    when :right_coerce
      remove_to_f_method(corrector, node.receiver)
      add_to_f_method(corrector, node.first_argument)
    when :fdiv
      correct_from_slash_to_fdiv(corrector, node, node.receiver, node.first_argument)
    end
  end
end

#remove_to_f_method(corrector, send_node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 125

def remove_to_f_method(corrector, send_node)
  corrector.remove(send_node.loc.dot)
  corrector.remove(send_node.loc.selector)
end

#right_coerce?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/float_division.rb', line 67

def_node_matcher :right_coerce?, <<~PATTERN
  (send _ :/ (send _ :to_f))
PATTERN