require 'test/unit' class TestAssertion < Test::Unit::TestCase def test_wrong_assertion error, line = assert_raise(ArgumentError) {assert(true, true)}, __LINE__ assert_match(/assertion message must be String or Proc, but TrueClass was given/, error.message) assert_match(/\A#{Regexp.quote(__FILE__)}:#{line}:/, error.backtrace[0]) end end