Class: RuboCop::Cop::Style::EvalWithLocation

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/style/eval_with_location.rb

Overview

Ensures that eval methods (‘eval`, `instance_eval`, `class_eval` and `module_eval`) are given filename and line number values (`_FILE_` and `_LINE_`). This data is used to ensure that any errors raised within the evaluated code will be given the correct identification in a backtrace.

The cop also checks that the line number given relative to ‘_LINE_` is correct.

This cop will autocorrect incorrect or missing filename and line number values. However, if ‘eval` is called without a binding argument, the cop will not attempt to automatically add a binding, or add filename and line values.

NOTE: This cop works only when a string literal is given as a code string. No offense is reported if a string variable is given as below:

source,ruby

code = <<-RUBY

def do_something
end

RUBY eval code # not checked.

Examples:

# bad
eval "  def do_something\n  end\n"

# bad
C.class_eval "  def do_something\n  end\n"

# good
eval "  def do_something\n  end\n", binding, __FILE__, __LINE__ + 1

# good
C.class_eval "  def do_something\n  end\n", __FILE__, __LINE__ + 1

Constant Summary collapse

MSG = 
'Pass `__FILE__` and `__LINE__` to `%<method_name>s`.'
MSG_EVAL = 
'Pass a binding, `__FILE__`, and `__LINE__` to `eval`.'
MSG_INCORRECT_FILE = 
'Incorrect file for `%<method_name>s`; ' \
'use `%<expected>s` instead of `%<actual>s`.'
MSG_INCORRECT_LINE = 
'Incorrect line number for `%<method_name>s`; ' \
'use `%<expected>s` instead of `%<actual>s`.'
RESTRICT_ON_SEND = 
i[eval class_eval module_eval instance_eval].freeze

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Instance Method Details

#line_with_offset?(node, sign, num) ⇒ Object 



75
76
77
78
79
80
 
# File 'lib/rubocop/cop/style/eval_with_location.rb', line 75

def_node_matcher :line_with_offset?, "{\n  (send #special_line_keyword? %1 (int %2))\n  (send (int %2) %1 #special_line_keyword?)\n}\n"

#on_send(node) ⇒ Object 



82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/rubocop/cop/style/eval_with_location.rb', line 82

def on_send(node)
  # Classes should not redefine eval, but in case one does, it shouldn't
  # register an offense. Only `eval` without a receiver and `Kernel.eval`
  # are considered.
  return if node.method?(:eval) && !valid_eval_receiver?(node.receiver)

  code = node.first_argument
  return unless code&.type?(:str, :dstr)

  check_location(node, code)
end

#valid_eval_receiver?(node) ⇒ Object 



70
71
72
 
# File 'lib/rubocop/cop/style/eval_with_location.rb', line 70

def_node_matcher :valid_eval_receiver?, "{ nil? (const {nil? cbase} :Kernel) }\n"