Fix raise_error when block does not raise an error

Also fill in missing tests for raise_error.

Author: mcmire

lib/super_diff/rspec/matcher_text_builders/raise_error.rb

@@ -5,7 +5,19 @@ class RaiseError < Base
         protected
 
         def actual_phrase
-          "Expected raised exception"
+          if actual
+            "Expected raised exception"
+          else
+            "Expected"
+          end
+        end
+
+        def add_actual_value
+          if actual
+            template.add_text_in_color(beta_color) { actual }
+          else
+            template.add_text("block")
+          end
         end
       end
     end

lib/super_diff/rspec/monkey_patches.rb

@@ -605,7 +605,9 @@ def actual_for_matcher_text
           end
 
           def actual_for_diff
-            @actual_error.message
+            if @actual_error
+              @actual_error.message
+            end
           end
 
           def expected_for_matcher_text
@@ -625,7 +627,11 @@ def diffable?
           end
 
           def expected_action_for_failure_message
-            "match"
+            if @actual_error
+              "match"
+            else
+              "raise error"
+            end
           end
 
           def matcher_text_builder_class
@@ -634,7 +640,7 @@ def matcher_text_builder_class
         end)
 
         def self.matcher_name
-          'raise error'
+          "raise error"
         end
       end