card/spec/support/matchers/view_matchers.rb
RSpec::Matchers.define :lack_errors do
match do |view|
view.to_s !~ /(?<![-\w])(error|not supported|translation missing)(?![-\w])/i
end
failure_message do |view|
%(View #{view} contains "error", "not supported", or "translation missing")
end
end