Fix failing tests

spec/expectations/expectation_spec.cr

@@ -59,8 +59,9 @@ describe Spectator::Expectations::Expectation do
         match_data = new_matcher(value).match(new_partial(value))
         expectation = Spectator::Expectations::Expectation.new(match_data, true)
         expectation.values.each do |labeled_value|
+          label = labeled_value.label
           value = labeled_value.value
-          value.to_s.should start_with(/not/i) if value.responds_to?(:negate)
+          value.to_s.should start_with(/not/i) if label == :expected
         end
       end
     end

src/spectator/matchers/alternative_match_data_value.cr

@@ -21,12 +21,12 @@ module Spectator::Matchers
 
     # Produces a stringified value.
     def to_s(io)
-      value.inspect(io)
+      io << value
     end
 
     # Produces a stringified value with additional information.
     def inspect(io)
-      value.inspect(io)
+      io << value
     end
   end
 end