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

Inherits:
Cop
  • Object
show all
Includes:
Alignment, RescueNode
Defined in:
lib/rubocop/cop/style/rescue_modifier.rb

Overview

This cop checks for uses of rescue in its modifier form.

The cop to check `rescue` in its modifier form is added for following reasons:

  • The syntax of modifier form `rescue` can be misleading because it might led 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 collapse

MSG = 
'Avoid using `rescue` in its modifier form.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Cop

#offenses

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from RescueNode

#on_new_investigation

Methods inherited from Cop

#add_offense, all, #corrections, #find_location, #highlights, joining_forces, #messages, #on_investigation_end, #on_new_investigation, #parse, qualified_cop_name, registry, support_autocorrect?, #support_autocorrect?

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#autocorrect(node) ⇒ Object 


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# File 'lib/rubocop/cop/style/rescue_modifier.rb', line 54

def autocorrect(node)
  parenthesized = parenthesized?(node)
  lambda do |corrector|
    corrector.replace(node, corrected_block(node, parenthesized))
    ParenthesesCorrector.correct(corrector, node.parent) if parenthesized
  end
end

#on_resbody(node) ⇒ Object 


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

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

  add_offense(node.parent)
end