assert_response failures include the exception message. Closes #10688.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8559 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 5 insertions, 1 deletions

diff --git a/actionpack/lib/action_controller/assertions/response_assertions.rb b/actionpack/lib/action_controller/assertions/response_assertions.rb
index 42bd7fb3d2..67dd3a5724 100644
--- a/actionpack/lib/action_controller/assertions/response_assertions.rb
+++ b/actionpack/lib/action_controller/assertions/response_assertions.rb
@@ -33,7 +33,11 @@ module ActionController
           elsif type.is_a?(Symbol) && @response.response_code == ActionController::StatusCodes::SYMBOL_TO_STATUS_CODE[type]
             assert_block("") { true } # to count the assertion
           else
-            assert_block(build_message(message, "Expected response to be a <?>, but was <?>", type, @response.response_code)) { false }
+            if @response.error?
+              assert_block(build_message(message, "Expected response to be a <?>, but was <?>\n<?>", type, @response.response_code, @response.template.instance_variable_get(:@exception).message)) { false }
+            else
+              assert_block(build_message(message, "Expected response to be a <?>, but was <?>", type, @response.response_code)) { false }
+            end
           end
         end
       end