Fallback to textdiffer when csv parsing fails

app/helpers/renderers/feedback_table_renderer.rb

@@ -319,17 +319,31 @@ def messages(msgs)
     end
   end
 
+  def render_accepted(builder, t)
+    if t[:format] == 'csv'
+      begin
+        return CsvDiffer.render_accepted(builder, t[:expected]) if CsvDiffer.limited_columns?(t[:expected])
+      rescue CSV::MalformedCSVError
+        # default to text if parsing failed
+      end
+    end
+    TextDiffer.render_accepted(builder, t[:expected])
+  end
+
   def differ(t)
-    if t[:format] == 'csv' && CsvDiffer.limited_columns?(t[:generated]) && CsvDiffer.limited_columns?(t[:expected])
-      CsvDiffer
-    else
-      TextDiffer
+    if t[:format] == 'csv'
+      begin
+        return CsvDiffer.new(t[:generated], t[:expected]) if CsvDiffer.limited_columns?(t[:generated]) && CsvDiffer.limited_columns?(t[:expected])
+      rescue CSV::MalformedCSVError
+        # default to text if parsing failed
+      end
     end
+    TextDiffer.new(t[:generated], t[:expected])
   end
 
   def test_accepted(t)
     @builder.div(class: 'test-accepted') do
-      differ(t).render_accepted(@builder, t[:generated])
+      render_accepted(@builder, t)
     end
   end
 
@@ -340,7 +354,7 @@ def test_failed(t)
   end
 
   def diff(t)
-    differ = differ(t).new(t[:generated], t[:expected])
+    differ = differ(t)
     @builder.div(class: "diffs show-#{@diff_type}") do
       @builder << differ.split
       @builder << differ.unified

test/controllers/submissions_controller_test.rb

@@ -477,4 +477,13 @@ def expected_score_string(*args)
 
     assert_response :ok
   end
+
+  test 'Should be able to render submission with malformed csv' do
+    submission = create :wrong_submission, code: 'select * from track where trackid = 1610',
+                                           result: '{"accepted":false,"status":"wrong","description":"Test failed","annotations":[{"text":"An SQL query should end with a semicolon","type":"info","row":1,"rows":1,"column":null,"columns":null,"externalUrl":null}],"groups":[{"description":"Result Validation","badgeCount":2,"groups":[{"accepted":false,"groups":[{"description":"Compare results","accepted":false,"tests":[{"expected":"\"title\"\\n\"Grace\"\\n\"Monster\"\\n\"The Greatest Hits\"\\n\"Throwing Copper\"\\n\"Toward the Within\"\\n\"Troublegum\"\\n\"Worst Case Scenario\"","format":"csv","messages":[{"format":"callout-danger","description":"Incorrect row count"}],"generated":"\"title\",\"trackid\",\"genre\",\"albumid\",\"artistid\",\"tracknumber\"\\n\"\"So Fast, So Numb\"\",\"1610\",\"Rock\",\"523\",\"229\",\"12\"","accepted":false}]}]},{"accepted":true,"groups":[{"description":"Column Types","accepted":true,"tests":[{"expected":"\"column\",\"type\"\\n\"title\",\"STRING\"","format":"csv","generated":"\"column\",\"type\"\\n\"title\",\"STRING\"\\n\"trackid\",\"INTEGER\"\\n\"genre\",\"STRING\"\\n\"albumid\",\"INTEGER\"\\n\"artistid\",\"INTEGER\"\\n\"tracknumber\",\"INTEGER\"","accepted":true}]}]},{"accepted":false,"groups":[{"description":"Order By","accepted":false,"tests":[{"expected":"correct order","generated":"incorrect order","accepted":false}]}]}]},{"description":"Query Result","badgeCount":0,"groups":[{"accepted":true,"groups":[{"description":"Full result","accepted":true,"tests":[{"expected":"","format":"csv","generated":"\"title\",\"trackid\",\"genre\",\"albumid\",\"artistid\",\"tracknumber\"\\n\"\"So Fast, So Numb\"\",\"1610\",\"Rock\",\"523\",\"229\",\"12\"","accepted":true}]}]}]}],"messages":[{"format":"html","description":"\\u003cstrong\\u003eWorker:\\u003c/strong\\u003e ixion","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003eMemory usage:\\u003c/strong\\u003e 40.61 MiB","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003ePrepare:\\u003c/strong\\u003e 0.13 seconds","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003eRuntime:\\u003c/strong\\u003e 0.92 seconds","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003eResult construction:\\u003c/strong\\u003e 0.02 seconds","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003eFinalize:\\u003c/strong\\u003e 0.01 seconds","permission":"zeus"},{"format":"html","description":"\\u003cstrong\\u003eTotal time:\\u003c/strong\\u003e 1.14 seconds","permission":"zeus"}]}'
+    sign_in submission.user
+    get submission_path(submission)
+
+    assert_response :ok
+  end
 end