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Class: RuboCop::Cop::Style::RescueModifier

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/rescue_modifier.rb

Overview

Checks for uses of rescue in its modifier form is added for following reasons:

  • The syntax of modifier form rescue can be misleading because it might lead us to believe that rescue handles the given exception but it actually rescue all exceptions to return the given rescue block. In this case, value returned by handle_error or SomeException.

  • Modifier form rescue would rescue all the exceptions. It would silently skip all exception or errors and handle the error. Example: If NoMethodError is raised, modifier form rescue would handle the exception.

Examples:

# bad
some_method rescue handle_error

# bad
some_method rescue SomeException

# good
begin
  some_method
rescue
  handle_error
end

# good
begin
  some_method
rescue SomeException
  handle_error
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::Alignment - Included

SPACE

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

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::RescueNode - Included

::RuboCop::Cop::RangeHelp - Included

#add_range, #column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.

#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.

#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::RuboCop::Cop::Alignment - 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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ]

  
# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 48

def self.autocorrect_incompatible_with
  [Style::MethodCallWithArgsParentheses]
end

Instance Method Details

#correct_rescue_block(corrector, node, parenthesized) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 70

def correct_rescue_block(corrector, node, parenthesized)
  operation, rescue_modifier, = *node
  *_, rescue_args = *rescue_modifier

  node_indentation, node_offset = indentation_and_offset(node, parenthesized)

  corrector.remove(range_between(operation.source_range.end_pos, node.source_range.end_pos))
  corrector.insert_before(operation, "begin\n#{node_indentation}")
  corrector.insert_after(operation, <<~RESCUE_CLAUSE.chop)

    #{node_offset}rescue
    #{node_indentation}#{rescue_args.source}
    #{node_offset}end
  RESCUE_CLAUSE
end

#indentation_and_offset(node, parenthesized) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 86

def indentation_and_offset(node, parenthesized)
  node_indentation = indentation(node)
  node_offset = offset(node)
  if parenthesized
    node_indentation = node_indentation[0...-1]
    node_offset = node_offset[0...-1]
  end
  [node_indentation, node_offset]
end

#on_resbody(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 52

def on_resbody(node)
  return unless rescue_modifier?(node)

  rescue_node = node.parent
  add_offense(rescue_node) do |corrector|
    parenthesized = parenthesized?(rescue_node)

    correct_rescue_block(corrector, rescue_node, parenthesized)
    ParenthesesCorrector.correct(corrector, rescue_node.parent) if parenthesized
  end
end

#parenthesized?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 66

def parenthesized?(node)
  node.parent && parentheses?(node.parent)
end