Prior to RSpec 1.2.7,
render_template in rspec-rails had a bug where
render_template('new') would pass if ‘newer’ was rendered (or anything that started with ‘new’). Internally
render_template was converting the string argument to a regular expression which was allowing ‘new’ to positively match ‘newer’ even though it was not an exact match. In RSpec-Rails 1.2.7 this bug has been fixed.