Use URL path extension as format in bad params exception handling

1 files changed, 15 insertions, 1 deletions

diff --git a/actionpack/test/dispatch/show_exceptions_test.rb b/actionpack/test/dispatch/show_exceptions_test.rb
index ffdf775836..14894d4b82 100644
--- a/actionpack/test/dispatch/show_exceptions_test.rb
+++ b/actionpack/test/dispatch/show_exceptions_test.rb
@@ -8,7 +8,7 @@ class ShowExceptionsTest < ActionDispatch::IntegrationTest
       case req.path
       when "/not_found"
         raise AbstractController::ActionNotFound
-      when "/bad_params"
+      when "/bad_params", "/bad_params.json"
         begin
           raise StandardError.new
         rescue
@@ -120,4 +120,18 @@ class ShowExceptionsTest < ActionDispatch::IntegrationTest
     assert_response 405
     assert_equal "", body
   end
+
+  test "bad params exception is returned in the correct format" do
+    @app = ProductionApp
+
+    get "/bad_params", headers: { 'action_dispatch.show_exceptions' => true }
+    assert_equal "text/html; charset=utf-8", response.headers["Content-Type"]
+    assert_response 400
+    assert_match(/400 error/, body)
+
+    get "/bad_params.json", headers: { 'action_dispatch.show_exceptions' => true }
+    assert_equal "application/json; charset=utf-8", response.headers["Content-Type"]
+    assert_response 400
+    assert_equal("{\"status\":400,\"error\":\"Bad Request\"}", body)
+  end
 end