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Class: RuboCop::Cop::Lint::SuppressedExceptionInNumberConversion

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb

Overview

Checks for cases where exceptions unrelated to the numeric constructors Integer(), Float(), BigDecimal(), Complex(), and Rational() may be unintentionally swallowed.

Examples:

# bad
Integer(arg) rescue nil

# bad
begin
  Integer(arg)
rescue
  nil
end

# bad
begin
  Integer(arg)
rescue
end

# good
Integer(arg, exception: false)

Cop Safety Information:

  • The cop is unsafe for autocorrection because unexpected errors occurring in the argument passed to numeric constructor (e.g., Integer()) can lead to incompatible behavior. For example, changing it to Integer(potential_exception_method_call, exception: false) ensures that exceptions raised by potential_exception_method_call are not ignored.

    Integer(potential_exception_method_call) rescue nil

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::TargetRubyVersion - Extended

::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 a 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::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_gem_version

Returns a gems locked versions (i.e.

#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

#begin_numeric_constructor_rescue_nil(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 56

def_node_matcher :begin_numeric_constructor_rescue_nil, <<~PATTERN
  (kwbegin
    (rescue
      $#numeric_method?
      (resbody $_? nil?
        {(nil) nil?}) nil?))
PATTERN

#constructor_receiver?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 75

def_node_matcher :constructor_receiver?, <<~PATTERN
  {nil? (const {nil? cbase} :Kernel)}
PATTERN

#expected_exception_classes_only?(exception_classes) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 103

def expected_exception_classes_only?(exception_classes)
  return true unless (arguments = exception_classes.first)

  (arguments.values.map(&:source) - EXPECTED_EXCEPTION_CLASSES).none?
end

#numeric_constructor_rescue_nil(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 49

def_node_matcher :numeric_constructor_rescue_nil, <<~PATTERN
  (rescue
    $#numeric_method?
    (resbody nil? nil? (nil)) nil?)
PATTERN

#numeric_method?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 65

def_node_matcher :numeric_method?, <<~PATTERN
  {
    (call #constructor_receiver? {:Integer :BigDecimal :Complex :Rational}
      _ _?)
    (call #constructor_receiver? :Float
      _)
  }
PATTERN

#on_rescue(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/suppressed_exception_in_number_conversion.rb', line 82

def on_rescue(node)
  if (method, exception_classes = begin_numeric_constructor_rescue_nil(node.parent))
    return unless expected_exception_classes_only?(exception_classes)

    node = node.parent
  else
    return unless (method = numeric_constructor_rescue_nil(node))
  end

  arguments = method.arguments.map(&:source) << 'exception: false'
  prefer = "#{method.method_name}(#{arguments.join(', ')})"
  prefer = "#{method.receiver.source}#{method.loc.dot.source}#{prefer}" if method.receiver

  add_offense(node, message: format(MSG, prefer: prefer)) do |corrector|
    corrector.replace(node, prefer)
  end
end