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Class: RuboCop::Cop::Style::RaiseArgs

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/raise_args.rb

Overview

Checks the args passed to fail and raise. For exploded style (default), it recommends passing the exception class and message to raise, rather than construct an instance of the error. It will still allow passing just a message, or the construction of an error with more than one argument.

The exploded style works identically, but with the addition that it will also suggest constructing error objects when the exception is passed multiple arguments.

The exploded style has an AllowedCompactTypes configuration option that takes an Array of exception name Strings.

Examples:

EnforcedStyle: exploded (default)

# bad
raise StandardError.new('message')

# good
raise StandardError, 'message'
fail 'message'
raise MyCustomError
raise MyCustomError.new(arg1, arg2, arg3)
raise MyKwArgError.new(key1: val1, key2: val2)

# With `AllowedCompactTypes` set to ['MyWrappedError']
raise MyWrappedError.new(obj)
raise MyWrappedError.new(obj), 'message'

EnforcedStyle: compact

# bad
raise StandardError, 'message'
raise RuntimeError, arg1, arg2, arg3

# good
raise StandardError.new('message')
raise MyCustomError
raise MyCustomError.new(arg1, arg2, arg3)
fail 'message'

Cop Safety Information:

  • This cop is unsafe because raise Foo calls Foo.exception, not Foo.new.

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

#acceptable_exploded_args?(args) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 132

def acceptable_exploded_args?(args)
  # Allow code like `raise Ex.new(arg1, arg2)`.
  return true if args.size > 1

  # Disallow zero arguments.
  return false if args.empty?

  arg = args.first

  # Allow code like `raise Ex.new(kw: arg)`.
  # Allow code like `raise Ex.new(*args)`.
  arg.hash_type? || arg.splat_type?
end

#allowed_non_exploded_type?(arg) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 146

def allowed_non_exploded_type?(arg)
  type = arg.receiver.const_name

  Array(cop_config['AllowedCompactTypes']).include?(type)
end

#check_compact(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 95

def check_compact(node)
  if node.arguments.size > 1
    exception = node.first_argument
    return if exception.send_type? && exception.first_argument&.hash_type?

    add_offense(node, message: format(COMPACT_MSG, method: node.method_name)) do |corrector|
      replacement = correction_exploded_to_compact(node)

      corrector.replace(node, replacement)
      opposite_style_detected
    end
  else
    correct_style_detected
  end
end

#check_exploded(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 111

def check_exploded(node)
  return correct_style_detected unless node.arguments.one?

  first_arg = node.first_argument

  return if !use_new_method?(first_arg) || acceptable_exploded_args?(first_arg.arguments)

  return if allowed_non_exploded_type?(first_arg)

  add_offense(node, message: format(EXPLODED_MSG, method: node.method_name)) do |corrector|
    replacement = correction_compact_to_exploded(node)

    corrector.replace(node, replacement)
    opposite_style_detected
  end
end

#correction_compact_to_exploded(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 69

def correction_compact_to_exploded(node)
  exception_node, _new, message_node = *node.first_argument

  arguments = [exception_node, message_node].compact.map(&:source).join(', ')

  if node.parent && requires_parens?(node.parent)
    "#{node.method_name}(#{arguments})"
  else
    "#{node.method_name} #{arguments}"
  end
end

#correction_exploded_to_compact(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 81

def correction_exploded_to_compact(node)
  exception_node, *message_nodes = *node.arguments
  return if message_nodes.size > 1

  argument = message_nodes.first.source
  exception_class = exception_node.receiver&.source || exception_node.source

  if node.parent && requires_parens?(node.parent)
    "#{node.method_name}(#{exception_class}.new(#{argument}))"
  else
    "#{node.method_name} #{exception_class}.new(#{argument})"
  end
end

#on_send(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 56

def on_send(node)
  return unless node.command?(:raise) || node.command?(:fail)

  case style
  when :compact
    check_compact(node)
  when :exploded
    check_exploded(node)
  end
end

#requires_parens?(parent) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 152

def requires_parens?(parent)
  parent.and_type? || parent.or_type? || (parent.if_type? && parent.ternary?)
end

#use_new_method?(first_arg) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/raise_args.rb', line 128

def use_new_method?(first_arg)
  first_arg.send_type? && first_arg.receiver && first_arg.method?(:new)
end