Example Custom Assertion

# File test/unit/assertions.rb, line 525
      def self.use_pp=(value)
        AssertionMessage.use_pp = value
      end

# File test/unit/assertions.rb, line 60
      def assert(boolean, message=nil)
        _wrap_assertion do
          assert_block("assert should not be called with a block.") { !block_given? }
          assert_block(build_message(message, "<?> is not true.", boolean)) { boolean }
        end
      end

# File test/unit/assertions.rb, line 45
      def assert_block(message="assert_block failed.") # :yields: 
        _wrap_assertion do
          if (! yield)
            raise AssertionFailedError.new(message.to_s)
          end
        end
      end

# File test/unit/assertions.rb, line 78
      def assert_equal(expected, actual, message=nil)
        full_message = build_message(message, "<?> expected but was\n<?>.\n", expected, actual)
        assert_block(full_message) { expected == actual }
      end

# File test/unit/assertions.rb, line 445
      def assert_in_delta(expected_float, actual_float, delta, message="")
        _wrap_assertion do
          {expected_float => "first float", actual_float => "second float", delta => "delta"}.each do |float, name|
            assert_respond_to(float, :to_f, "The arguments must respond to to_f; the #{name} did not")
          end
          assert_operator(delta, :>=, 0.0, "The delta should not be negative")
          full_message = build_message(message, "<?> and\n<?> expected to be within\n<?> of each other.\n", expected_float, actual_float, delta)
          assert_block(full_message) { (expected_float.to_f - actual_float.to_f).abs <= delta.to_f }
        end
      end

# File test/unit/assertions.rb, line 153
      def assert_instance_of(klass, object, message="")
        _wrap_assertion do
          assert_equal(Class, klass.class, "assert_instance_of takes a Class as its first argument")
          full_message = build_message(message, "<?> expected to be an instance of\n<?> but was\n<?>.\n", object, klass, object.class)
          assert_block(full_message){object.instance_of?(klass)}
        end
      end

# File test/unit/assertions.rb, line 184
      def assert_kind_of(klass, object, message="")
        _wrap_assertion do
          assert(klass.kind_of?(Module), "The first parameter to assert_kind_of should be a kind_of Module.")
          full_message = build_message(message, "<?>\nexpected to be kind_of\\?\n<?> but was\n<?>.", object, klass, object.class)
          assert_block(full_message){object.kind_of?(klass)}
        end
      end

# File test/unit/assertions.rb, line 223
      def assert_match(pattern, string, message="")
        _wrap_assertion do
          pattern = case(pattern)
            when String
              Regexp.new(Regexp.escape(pattern))
            else
              pattern
          end
          full_message = build_message(message, "<?> expected to be =~\n<?>.", string, pattern)
          assert_block(full_message) { string =~ pattern }
        end
      end

# File test/unit/assertions.rb, line 173
      def assert_nil(object, message="")
        assert_equal(nil, object, message)
      end

# File test/unit/assertions.rb, line 370
      def assert_no_match(regexp, string, message="")
        _wrap_assertion do
          assert_instance_of(Regexp, regexp, "The first argument to assert_no_match should be a Regexp.")
          full_message = build_message(message, "<?> expected to not match\n<?>.", regexp, string)
          assert_block(full_message) { regexp !~ string }
        end
      end

# File test/unit/assertions.rb, line 346
      def assert_not_equal(expected, actual, message="")
        full_message = build_message(message, "<?> expected to be != to\n<?>.", expected, actual)
        assert_block(full_message) { expected != actual }
      end

# File test/unit/assertions.rb, line 358
      def assert_not_nil(object, message="")
        full_message = build_message(message, "<?> expected to not be nil.", object)
        assert_block(full_message){!object.nil?}
      end

# File test/unit/assertions.rb, line 328
      def assert_not_same(expected, actual, message="")
        full_message = build_message(message, "<?>\nwith id <?> expected to not be equal\\\\? to\n<?>\nwith id <?>.\n", expected, expected.__id__, actual, actual.__id__)
        assert_block(full_message) { !actual.equal?(expected) }
      end

# File test/unit/assertions.rb, line 288
      def assert_nothing_raised(*args)
        _wrap_assertion do
          if Module === args.last
            message = ""
          else
            message = args.pop
          end
          exceptions, modules = _check_exception_class(args)
          begin
            yield
          rescue Exception => e
            if ((args.empty? && !e.instance_of?(AssertionFailedError)) ||
                _expected_exception?(e, exceptions, modules))
              assert_block(build_message(message, "Exception raised:\n?", e)){false}
            else
              raise
            end
          end
          nil
        end
      end

# File test/unit/assertions.rb, line 421
      def assert_nothing_thrown(message="", &proc)
        _wrap_assertion do
          assert(block_given?, "Should have passed a block to assert_nothing_thrown")
          begin
            proc.call
          rescue NameError, ThreadError => error
            if UncaughtThrow[error.class] !~ error.message
              raise error
            end
            full_message = build_message(message, "<?> was thrown when nothing was expected", $1.intern)
            flunk(full_message)
          end
          assert(true, "Expected nothing to be thrown")
        end
      end

# File test/unit/assertions.rb, line 265
      def assert_operator(object1, operator, object2, message="")
        _wrap_assertion do
          full_message = build_message(nil, "<?>\ngiven as the operator for #assert_operator must be a Symbol or #respond_to\\?(:to_str).", operator)
          assert_block(full_message){operator.kind_of?(Symbol) || operator.respond_to?(:to_str)}
          full_message = build_message(message, "<?> expected to be\n?\n<?>.\n", object1, AssertionMessage.literal(operator), object2)
          assert_block(full_message) { object1.__send__(operator, object2) }
        end
      end

# File test/unit/assertions.rb, line 111
      def assert_raise(*args)
        _wrap_assertion do
          if Module === args.last
            message = ""
          else
            message = args.pop
          end
          exceptions, modules = _check_exception_class(args)
          expected = args.size == 1 ? args.first : args
          actual_exception = nil
          full_message = build_message(message, "<?> exception expected but none was thrown.", expected)
          assert_block(full_message) do
            begin
              yield
            rescue Exception => actual_exception
              break
            end
            false
          end
          full_message = build_message(message, "<?> exception expected but was\n?", expected, actual_exception)
          assert_block(full_message) {_expected_exception?(actual_exception, exceptions, modules)}
          actual_exception
        end
      end

# File test/unit/assertions.rb, line 142
      def assert_raises(*args, &block)
        assert_raise(*args, &block)
      end

# File test/unit/assertions.rb, line 199
      def assert_respond_to(object, method, message="")
        _wrap_assertion do
          full_message = build_message(nil, "<?>\ngiven as the method name argument to #assert_respond_to must be a Symbol or #respond_to\\?(:to_str).", method)

          assert_block(full_message) do
            method.kind_of?(Symbol) || method.respond_to?(:to_str)
          end
          full_message = build_message(message, "<?>\nof type <?>\nexpected to respond_to\\\\?<?>.\n", object, object.class, method)
          assert_block(full_message) { object.respond_to?(method) }
        end
      end

# File test/unit/assertions.rb, line 245
      def assert_same(expected, actual, message="")
        full_message = build_message(message, "<?>\nwith id <?> expected to be equal\\\\? to\n<?>\nwith id <?>.\n", expected, expected.__id__, actual, actual.__id__)
        assert_block(full_message) { actual.equal?(expected) }
      end

# File test/unit/assertions.rb, line 473
      def assert_send(send_array, message="")
        _wrap_assertion do
          assert_instance_of(Array, send_array, "assert_send requires an array of send information")
          assert(send_array.size >= 2, "assert_send requires at least a receiver and a message name")
          full_message = build_message(message, "<?> expected to respond to\n<?(?)> with a true value.\n", send_array[0], AssertionMessage.literal(send_array[1].to_s), send_array[2..-1])
          assert_block(full_message) { send_array[0].__send__(send_array[1], *send_array[2..-1]) }
        end
      end

# File test/unit/assertions.rb, line 390
      def assert_throws(expected_symbol, message="", &proc)
        _wrap_assertion do
          assert_instance_of(Symbol, expected_symbol, "assert_throws expects the symbol that should be thrown for its first argument")
          assert_block("Should have passed a block to assert_throws."){block_given?}
          caught = true
          begin
            catch(expected_symbol) do
              proc.call
              caught = false
            end
            full_message = build_message(message, "<?> should have been thrown.", expected_symbol)
            assert_block(full_message){caught}
          rescue NameError, ThreadError => error
            if UncaughtThrow[error.class] !~ error.message
              raise error
            end
            full_message = build_message(message, "<?> expected to be thrown but\n<?> was thrown.", expected_symbol, $1.intern)
            flunk(full_message)
          end
        end
      end

# File test/unit/assertions.rb, line 491
      def build_message(head, template=nil, *arguments)
        template &&= template.chomp
        return AssertionMessage.new(head, template, arguments)
      end

# File test/unit/assertions.rb, line 317
      def flunk(message="Flunked")
        assert_block(build_message(message)){false}
      end