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Class: RuboCop::Cop::Lint::NumberConversion

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/lint/number_conversion.rb

Overview

Warns the usage of unsafe number conversions. Unsafe number conversion can cause unexpected error if auto type conversion fails. Cop prefer parsing with number class instead.

Conversion with Integer, Float, etc. will raise an ArgumentError if given input that is not numeric (eg. an empty string), whereas to_i, etc. will try to convert regardless of input (''.to_i ⇒ 0). As such, this cop is disabled by default because it’s not necessarily always correct to raise if a value is not numeric.

Note
Some values cannot be converted properly using one of the Kernel method (for instance, Time and DateTime values are allowed by this cop by default). Similarly, Rails' duration methods do not work well with Integer() and can be allowed with AllowedMethods. By default, there are no methods to allowed.

Examples:

# bad

'10'.to_i
'10.2'.to_f
'10'.to_c
'1/3'.to_r
['1', '2', '3'].map(&:to_i)
foo.try(:to_f)
bar.send(:to_c)

# good

Integer('10', 10)
Float('10.2')
Complex('10')
Rational('1/3')
['1', '2', '3'].map { |i| Integer(i, 10) }
foo.try { |i| Float(i) }
bar.send { |i| Complex(i) }

AllowedMethods: [] (default)

# bad
10.minutes.to_i

AllowedMethods: [minutes]

# good
10.minutes.to_i

AllowedPatterns: [] (default)

# bad
10.minutes.to_i

AllowedPatterns: ['min*']

# good
10.minutes.to_i

IgnoredClasses: [Time, DateTime] (default)

# good
Time.now.to_datetime.to_i

Cop Safety Information:

  • Autocorrection is unsafe because it is not guaranteed that the replacement Kernel methods are able to properly handle the input if it is not a standard class.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

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::AllowedPattern - Included

::RuboCop::Cop::AllowedMethods - 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

#allow_receiver?(receiver) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 165

def allow_receiver?(receiver)
  if receiver.numeric_type? || (receiver.send_type? &&
    (conversion_method?(receiver.method_name) ||
    allowed_method_name?(receiver.method_name)))
    true
  elsif (receiver = top_receiver(receiver))
    receiver.const_type? && ignored_class?(receiver.const_name)
  else
    false
  end
end

#allowed_method_name?(name) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 177

def allowed_method_name?(name)
  allowed_method?(name) || matches_allowed_pattern?(name)
end

#conversion_method?(method_name) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 187

def conversion_method?(method_name)
  CONVERSION_METHODS.include?(method_name)
end

#correct_method(node, receiver) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 151

def correct_method(node, receiver)
  format(CONVERSION_METHOD_CLASS_MAPPING[node.method_name], number_object: receiver.source)
end

#correct_sym_method(to_method) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 155

def correct_sym_method(to_method)
  body = format(CONVERSION_METHOD_CLASS_MAPPING[to_method], number_object: 'i')
  "{ |i| #{body} }"
end

#handle_as_symbol(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 134

def handle_as_symbol(node)
  to_method_symbol(node) do |receiver, sym_node, to_method|
    next if receiver.nil? || !node.arguments.one?

    message = format(
      MSG,
      current: sym_node.source,
      corrected_method: correct_sym_method(to_method)
    )
    add_offense(node, message: message) do |corrector|
      remove_parentheses(corrector, node) if node.parenthesized?

      corrector.replace(sym_node, correct_sym_method(to_method))
    end
  end
end

#handle_conversion_method(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 115

def handle_conversion_method(node)
  to_method(node) do |receiver, to_method|
    next if receiver.nil? || allow_receiver?(receiver)

    message = format(
      MSG,
      current: "#{receiver.source}.#{to_method}",
      corrected_method: correct_method(node, receiver)
    )
    add_offense(node, message: message) do |corrector|
      next if part_of_ignored_node?(node)

      corrector.replace(node, correct_method(node, node.receiver))

      ignore_node(node)
    end
  end
end

#ignored_class?(name) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 195

def ignored_class?(name)
  ignored_classes.include?(name.to_s)
end

#ignored_classes (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 191

def ignored_classes
  cop_config.fetch('IgnoredClasses', [])
end

#on_csend(node)

Alias for #on_send.

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 111

alias on_csend on_send

#on_send(node) Also known as: #on_csend

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 107

def on_send(node)
  handle_conversion_method(node)
  handle_as_symbol(node)
end

#remove_parentheses(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 160

def remove_parentheses(corrector, node)
  corrector.replace(node.loc.begin, ' ')
  corrector.remove(node.loc.end)
end

#to_method(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 93

def_node_matcher :to_method, <<~PATTERN
  (call $_ ${#{METHODS}})
PATTERN

#to_method_symbol(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 98

def_node_matcher :to_method_symbol, <<~PATTERN
  (call _ $_ ${
    {
      (sym ${#{METHODS}})
      (block_pass (sym ${#{METHODS}}))
    }
  } ...)
PATTERN

#top_receiver(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/number_conversion.rb', line 181

def top_receiver(node)
  receiver = node
  receiver = receiver.receiver until receiver.receiver.nil?
  receiver
end