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