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Class: RuboCop::Cop::Lint::InheritException

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/inherit_exception.rb

Overview

Looks for error classes inheriting from Exception. It is configurable to suggest using either StandardError (default) or RuntimeError instead.

Examples:

EnforcedStyle: standard_error (default)

# bad

class C < Exception; end

C = Class.new(Exception)

# good

class C < StandardError; end

C = Class.new(StandardError)

EnforcedStyle: runtime_error

# bad

class C < Exception; end

C = Class.new(Exception)

# good

class C < RuntimeError; end

C = Class.new(RuntimeError)

Cop Safety Information:

  • This cop’s autocorrection is unsafe because rescue that omit exception class handle StandardError and its subclasses, but not Exception and its subclasses.

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 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::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

#class_new_call?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 53

def_node_matcher :class_new_call?, <<~PATTERN
  (send
    (const {cbase nil?} :Class) :new
    $(const {cbase nil?} _))
PATTERN

#exception_class?(class_node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 87

def exception_class?(class_node)
  class_node.const_name == 'Exception'
end

#inherit_exception_class_with_omitted_namespace?(class_node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 91

def inherit_exception_class_with_omitted_namespace?(class_node)
  return false if class_node.parent_class.namespace&.cbase_type?

  class_node.left_siblings.any? do |sibling|
    sibling.respond_to?(:identifier) && exception_class?(sibling.identifier)
  end
end

#message(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 83

def message(node)
  format(MSG, prefer: preferred_base_class, current: node.const_name)
end

#on_class(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 59

def on_class(node)
  return unless node.parent_class && exception_class?(node.parent_class)
  return if inherit_exception_class_with_omitted_namespace?(node)

  message = message(node.parent_class)

  add_offense(node.parent_class, message: message) do |corrector|
    corrector.replace(node.parent_class, preferred_base_class)
  end
end

#on_send(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 70

def on_send(node)
  constant = class_new_call?(node)
  return unless constant && exception_class?(constant)

  message = message(constant)

  add_offense(constant, message: message) do |corrector|
    corrector.replace(constant, preferred_base_class)
  end
end

#preferred_base_class (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/inherit_exception.rb', line 99

def preferred_base_class
  PREFERRED_BASE_CLASS[style]
end