class RuboCop::Cop::Lint::ErbNewArguments

Emulates the following Ruby warnings in Ruby 2.6.

source,console

$ cat example.rb ERB.new(‘hi’, nil, ‘-’, ‘@output_buffer’) $ ruby -rerb example.rb example.rb:1: warning: Passing safe_level with the 2nd argument of ERB.new is deprecated. Do not use it, and specify other arguments as keyword arguments. example.rb:1: warning: Passing trim_mode with the 3rd argument of ERB.new is deprecated. Use keyword argument like ERB.new(str, trim_mode:…) instead. example.rb:1: warning: Passing eoutvar with the 4th argument of ERB.new is deprecated. Use keyword argument like ERB.new(str, eoutvar: …) instead.


Now non-keyword arguments other than first one are softly deprecated and will be removed when Ruby 2.5 becomes EOL. ‘ERB.new` with non-keyword arguments is deprecated since ERB 2.2.0. Use `:trim_mode` and `:eoutvar` keyword arguments to `ERB.new`. This cop identifies places where `ERB.new(str, trim_mode, eoutvar)` can be replaced by `ERB.new(str, :trim_mode: trim_mode, eoutvar: eoutvar)`.

@example

# Target codes supports Ruby 2.6 and higher only
# bad
ERB.new(str, nil, '-', '@output_buffer')

# good
ERB.new(str, trim_mode: '-', eoutvar: '@output_buffer')

# Target codes supports Ruby 2.5 and lower only
# good
ERB.new(str, nil, '-', '@output_buffer')

# Target codes supports Ruby 2.6, 2.5 and lower
# bad
ERB.new(str, nil, '-', '@output_buffer')

# good
# Ruby standard library style
# https://github.com/ruby/ruby/commit/3406c5d
if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
  ERB.new(str, trim_mode: '-', eoutvar: '@output_buffer')
else
  ERB.new(str, nil, '-', '@output_buffer')
end

# good
# Use `RUBY_VERSION` style
if RUBY_VERSION >= '2.6'
  ERB.new(str, trim_mode: '-', eoutvar: '@output_buffer')
else
  ERB.new(str, nil, '-', '@output_buffer')
end

Constants

MESSAGE_EOUTVAR
MESSAGE_SAFE_LEVEL
MESSAGE_TRIM_MODE
RESTRICT_ON_SEND

Public Instance Methods

on_send(node) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 86
def on_send(node)
  erb_new_with_non_keyword_arguments(node) do |arguments|
    return if arguments.empty? || correct_arguments?(arguments)

    arguments[1..3].each_with_index do |argument, i|
      next if !argument || argument.hash_type?

      add_offense(
        argument, message: message(i, argument.source)
      ) do |corrector|
        autocorrect(corrector, node)
      end
    end
  end
end

Private Instance Methods

arguments_range(node) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 160
def arguments_range(node)
  arguments = node.arguments

  range_between(arguments.first.source_range.begin_pos, arguments.last.source_range.end_pos)
end
autocorrect(corrector, node) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 115
def autocorrect(corrector, node)
  str_arg = node.first_argument.source

  kwargs = build_kwargs(node)
  overridden_kwargs = override_by_legacy_args(kwargs, node)

  good_arguments = [str_arg, overridden_kwargs].flatten.compact.join(', ')

  corrector.replace(arguments_range(node), good_arguments)
end
build_kwargs(node) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 130
def build_kwargs(node)
  return [nil, nil] unless node.last_argument.hash_type?

  trim_mode_arg, eoutvar_arg = nil

  node.last_argument.pairs.each do |pair|
    case pair.key.source
    when 'trim_mode'
      trim_mode_arg = "trim_mode: #{pair.value.source}"
    when 'eoutvar'
      eoutvar_arg = "eoutvar: #{pair.value.source}"
    end
  end

  [trim_mode_arg, eoutvar_arg]
end
correct_arguments?(arguments) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 126
def correct_arguments?(arguments)
  arguments.size == 1 || (arguments.size == 2 && arguments[1].hash_type?)
end
message(positional_argument_index, arg_value) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 104
def message(positional_argument_index, arg_value)
  case positional_argument_index
  when 0
    MESSAGE_SAFE_LEVEL
  when 1
    format(MESSAGE_TRIM_MODE, arg_value: arg_value)
  when 2
    format(MESSAGE_EOUTVAR, arg_value: arg_value)
  end
end
override_by_legacy_args(kwargs, node) click to toggle source
# File lib/rubocop/cop/lint/erb_new_arguments.rb, line 147
def override_by_legacy_args(kwargs, node)
  arguments = node.arguments
  overridden_kwargs = kwargs.dup

  overridden_kwargs[0] = "trim_mode: #{arguments[2].source}" if arguments[2]

  if arguments[3] && !arguments[3].hash_type?
    overridden_kwargs[1] = "eoutvar: #{arguments[3].source}"
  end

  overridden_kwargs
end