method

assert

v1_9_3_392 - Show latest stable - 1 note - Class: Test::Unit::Assertions

assert(test, msg = UNASSIGNED) public

Tests if test is true.

msg may be a String or a Proc. If msg is a String, it will be used as the failure message. Otherwise, the result of calling msg will be used as the message if the assertion fails.

If no msg is given, a default message will be used.

assert(false, "This was expected to be true")

Show source

# File lib/test/unit/assertions.rb, line 29
      def assert(test, msg = UNASSIGNED)
        case msg
        when UNASSIGNED
          msg = nil
        when String, Proc
        else
          bt = caller.reject { |s| s.rindex(MINI_DIR, 0) }
          raise ArgumentError, "assertion message must be String or Proc, but #{msg.class} was given.", bt
        end
        super
      end

March 11, 2010

0 thanks

Use message param

The message param is invaluable in case test fails – if you use it to display relevant info, you will find out what went wrong much faster.

Reworking the silly example above:

assert some_list.include?(5)

will only tell you that

<false> is not true.

which isn’t terribly helpful, is it? But if you use message like that:

assert some_list.include?(5), "some_list = #{some_list.inspect}"

the output will be:

some_list = [1, 2].
<false> is not true.

which in most cases should give you strong hints as to why the test failed.

assert

Related methods

Use message param