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 included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from RescueNode

#investigate

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, #correct, department, #disable_uncorrectable, #duplicate_location?, #excluded_file?, #external_dependency_checksum, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, #parse, qualified_cop_name, #reason_to_not_correct, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AST::Sexp

#s

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_offense, #disable_uncorrectable?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object


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

def autocorrect(node)
  operation, rescue_modifier, = *node
  *_, rescue_args = *rescue_modifier

  indent = indentation(node)
  correction =
    "begin\n" \
    "#{operation.source.gsub(/^/, indent)}" \
    "\n#{offset(node)}rescue\n" \
    "#{rescue_args.source.gsub(/^/, indent)}" \
    "\n#{offset(node)}end"

  lambda do |corrector|
    corrector.replace(node.source_range, correction)
  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