module ActiveSupport::Testing::Deprecation

def assert_not_deprecated(deprecator = nil, &block)

end
CustomDeprecator.warn "message" # passes assertion
assert_not_deprecated do

end
ActiveSupport::Deprecation.warn "message" # fails assertion
assert_not_deprecated do

If no +deprecator+ is given, defaults to ActiveSupport::Deprecation.

end
CustomDeprecator.warn "message" # fails assertion
assert_not_deprecated(CustomDeprecator) do

Asserts that no deprecation warnings are emitted by the given deprecator during the execution of the yielded block. 
def assert_not_deprecated(deprecator = nil, &block)
  result, deprecations = collect_deprecations(deprecator, &block)
  assert deprecations.empty?, "Expected no deprecation warning within the block but received #{deprecations.size}: \n  #{deprecations * "\n  "}"
  result
end