Lint-ErbNewArguments.md

Pattern: Misuse of ERB.new

Issue: -

Description

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 rule identifies places where ERB.new(str, trim_mode, eoutvar) can be replaced by ERB.new(str, :trim_mode: trim_mode, eoutvar: eoutvar).

Examples

# 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

Further Reading

• RuboCop - Lint/ErbNewArguments