Unittest Failures Not Displayed For Optional Questions

[HassanAbouelela]

Description

Submitting a failing solution to a non-required tested field blocks submission silently and rejects submission.

Reproduction:

form question:

"questions": [
 {
 "_id": "code",
 "name": "Code",
 "type": "code",
 "required": false,
 "data": {
 "language": "python",
 "unittests": {
 "allow_failure": false,
 "tests": {
 "test_something": "self.assertTrue(False)"
 }
 }
 }
 }
]

Submit anything to a form with this question.

Desired Behavior

This is a bit of an edge case, but I believe the correct behavior should be:

1. If the field has data, and that fails, show the user the failure
2. If it does not have data, submit without a solution

Scenario 2 requires modifying the backend, while 1 is purely frontend.