assert_deprecated

Asserts that a matching deprecation warning was emitted by the given deprecator during the execution of the yielded block.

assert_deprecated(/foo/, CustomDeprecator) do
  CustomDeprecator.warn "foo should no longer be used"
end

The match object may be a Regexp, or String appearing in the message.

assert_deprecated('foo', CustomDeprecator) do
  CustomDeprecator.warn "foo should no longer be used"
end

If the match is omitted (or explicitly nil), any deprecation warning will match.

assert_deprecated(nil, CustomDeprecator) do
  CustomDeprecator.warn "foo should no longer be used"
end

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

assert_deprecated do
  ActiveSupport::Deprecation.warn "foo should no longer be used"
end