Add an optional submission cap and allow per-student overrides

tin/apps/assignments/admin.py

@@ -10,6 +10,7 @@
     FileAction,
     Folder,
     MossResult,
+    PerStudentData,
     Quiz,
     QuizLogMessage,
 )
@@ -140,3 +141,6 @@ def match(self, obj):
         elif obj.match_type == "C":
             return f"*{obj.match_value}*"
         return ""
+
+
+admin.site.register(PerStudentData)

tin/apps/assignments/forms.py

@@ -7,7 +7,7 @@
 from django.conf import settings
 
 from ..submissions.models import Submission
-from .models import Assignment, Folder, MossResult
+from .models import Assignment, Folder, MossResult, PerStudentData
 
 logger = getLogger(__name__)
 
@@ -66,6 +66,7 @@ class Meta:
             "grader_timeout",
             "grader_has_network_access",
             "has_network_access",
+            "submission_cap",
             "submission_limit_count",
             "submission_limit_interval",
             "submission_limit_cooldown",
@@ -136,6 +137,7 @@ class Meta:
                     "submission_limit_count",
                     "submission_limit_interval",
                     "submission_limit_cooldown",
+                    "submission_cap",
                 ),
                 "collapsed": True,
             },
@@ -171,6 +173,7 @@ class Meta:
             "instructions that need to be hidden until the student enters the monitored quiz environment.",
             "quiz_description_markdown": "This allows adding images, code blocks, or hyperlinks to the quiz "
             "description.",
+            "submission_cap": "The maximum number of submissions that can be made. It can be overridden on a per-student basis.",
         }
         widgets = {
             "description": forms.Textarea(attrs={"cols": 30, "rows": 8}),
@@ -241,3 +244,12 @@ class Meta:
             "name",
         ]
         help_texts = {"name": "Note: Folders are ordered alphabetically."}
+
+
+class PerStudentDataForm(forms.ModelForm):
+    class Meta:
+        model = PerStudentData
+        fields = [
+            "submission_cap",
+        ]
+        help_texts = {"submission_cap": "The maximum number of submissions that can be made."}

tin/apps/assignments/migrations/0033_assignment_submission_cap_perstudentdata.py

@@ -0,0 +1,31 @@
+# Generated by Django 4.2.14 on 2024-08-16 19:44
+
+from django.conf import settings
+import django.core.validators
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('assignments', '0032_assignment_quiz_description_and_more'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='assignment',
+            name='submission_cap',
+            field=models.PositiveSmallIntegerField(null=True, validators=[django.core.validators.MinValueValidator(1)]),
+        ),
+        migrations.CreateModel(
+            name='PerStudentData',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('submission_cap', models.PositiveSmallIntegerField(default=None, null=True)),
+                ('assignment', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='student_data', to='assignments.assignment')),
+                ('student', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+    ]

tin/apps/assignments/models.py

@@ -159,6 +159,7 @@ class Assignment(models.Model):
 
     has_network_access = models.BooleanField(default=False)
 
+    # WARNING: this is the rate limit
     submission_limit_count = models.PositiveIntegerField(
         default=90,
         validators=[MinValueValidator(10)],
@@ -172,6 +173,11 @@ class Assignment(models.Model):
         validators=[MinValueValidator(10)],
     )
 
+    submission_cap = models.PositiveSmallIntegerField(
+        null=True,
+        validators=[MinValueValidator(1)],
+    )
+
     last_action_output = models.CharField(max_length=16 * 1024, default="", null=False, blank=True)
 
     is_quiz = models.BooleanField(default=False)
@@ -192,6 +198,23 @@ def get_absolute_url(self):
     def __repr__(self):
         return self.name
 
+    def within_submission_limit(self, student) -> bool:
+        """Check if a student is within the submission limit for an assignment."""
+        # assignments can have infinite submissions, and so can teachers.
+        if not student.is_student:
+            return True
+        data, created = self.student_data.get_or_create(student=student)
+        if created:
+            data.submission_cap = self.submission_cap
+            data.save()
+
+        # note that this doesn't care about killed/incomplete submissions
+        submission_count = self.submissions.filter(student=student).count()
+        return submission_count < (data.submission_cap or float("inf"))
+
+    def find_student_data(self, student) -> PerStudentData:
+        return self.student_data.get_or_create(student=student)[0]
+
     def make_assignment_dir(self) -> None:
         """Creates the directory where the assignment grader scripts go."""
         assignment_path = os.path.join(settings.MEDIA_ROOT, f"assignment-{self.id}")
@@ -371,6 +394,26 @@ def quiz_issues_for_student(self, student) -> bool:
         )
 
 
+class PerStudentData(models.Model):
+    """A collection of per-student data for each :class:`.Assignment`."""
+
+    assignment = models.ForeignKey(
+        Assignment,
+        on_delete=models.CASCADE,
+        related_name="student_data",
+    )
+
+    student = models.ForeignKey(
+        get_user_model(),
+        on_delete=models.CASCADE,
+    )
+
+    submission_cap = models.PositiveSmallIntegerField(null=True, default=None)
+
+    def __str__(self):
+        return f"Override for {self.student} @ Assignment {self.assignment}"
+
+
 class CooldownPeriod(models.Model):
     assignment = models.ForeignKey(
         Assignment,

tin/apps/assignments/tests/test_assignments.py

@@ -24,6 +24,7 @@ def test_create_assignment(client, course) -> None:
         "submission_limit_cooldown": "30",
         "is_quiz": False,
         "quiz_action": "2",
+        "submission_cap": "100",
     }
     response = client.post(
         reverse("assignments:add", args=[course.id]),
@@ -103,3 +104,57 @@ def test_csv_of_missing_assignment_graded(client, assignment, student):
     assert float(raw) == max_points
     assert float(final) == max_points
     assert formatted == "150 / 300 (50.00%)"
+
+
+@login("student")
+@pytest.mark.parametrize("is_quiz", (True, False))
+def test_submission_cap(client, assignment, student, is_quiz):
+    assignment.is_quiz = is_quiz
+    assignment.submission_cap = 1
+    assignment.save()
+    code = "print('hello, world')"
+    assignment.save_grader_file(code)
+
+    def submit():
+        url = "assignments:quiz" if is_quiz else "assignments:submit"
+        return client.post(
+            reverse(url, args=[assignment.id]),
+            {"text": "print('I hate fun')"},
+        )
+
+    response = submit()
+    assert response.status_code == 302, f"Expected status code 302, got {response}"
+
+    # but now we've passed the cap
+    response = submit()
+    assert response.status_code == 403, f"Expected status code 403, got {response}"
+
+
+@login("student")
+@pytest.mark.parametrize("is_quiz", (True, False))
+def test_submission_cap_with_override(client, assignment, student, is_quiz):
+    assignment.is_quiz = is_quiz
+    assignment.submission_cap = 1
+    assignment.save()
+    code = "print('hello, world')"
+    assignment.save_grader_file(code)
+
+    # add student override
+    assignment.student_data.create(student=student, submission_cap=2)
+
+    def submit():
+        url = "assignments:quiz" if is_quiz else "assignments:submit"
+        return client.post(
+            reverse(url, args=[assignment.id]),
+            {"text": "print('I hate fun')"},
+        )
+
+    # first and second submission should be fine
+    response = submit()
+    assert response.status_code == 302, f"Expected status code 302, got {response}"
+    response = submit()
+    assert response.status_code == 302, f"Expected status code 302, got {response}"
+
+    # but now we've passed the cap for the student
+    response = submit()
+    assert response.status_code == 403, f"Expected status code 403, got {response}"

tin/apps/assignments/urls.py

@@ -13,6 +13,12 @@
     path("<int:assignment_id>/delete", views.delete_view, name="delete"),
     path("<int:assignment_id>/grader", views.manage_grader_view, name="manage_grader"),
     path("<int:assignment_id>/grader/download", views.download_grader_view, name="download_grader"),
+    path("<int:assignment_id>/manage_students", views.manage_students_view, name="manage_students"),
+    path(
+        "<int:assignment_id>/<int:student_id>/manage",
+        views.manage_student,
+        name="edit_student_data",
+    ),
     path("<int:assignment_id>/files", views.manage_files_view, name="manage_files"),
     path(
         "<int:assignment_id>/files/download/<int:file_id>",

tin/apps/assignments/views.py

@@ -30,6 +30,7 @@
     FolderForm,
     GraderScriptUploadForm,
     MossForm,
+    PerStudentDataForm,
     TextSubmissionForm,
 )
 from .models import Assignment, CooldownPeriod, QuizLogMessage
@@ -71,6 +72,7 @@ def show_view(request, assignment_id):
                 "is_student": course.is_student_in_course(request.user),
                 "is_teacher": request.user in course.teacher.all(),
                 "quiz_accessible": quiz_accessible,
+                "within_submission_limit": assignment.within_submission_limit(request.user),
             },
         )
     else:
@@ -274,6 +276,38 @@ def delete_view(request, assignment_id):
     return redirect(reverse("courses:show", args=(course.id,)))
 
 
+@teacher_or_superuser_required
+def manage_students_view(request, assignment_id):
+    assignment = Assignment.objects.get(id=assignment_id)
+    course = assignment.course
+    return render(
+        request,
+        "assignments/manage_students.html",
+        {"students": course.students.all(), "assignment": assignment},
+    )
+
+
+@teacher_or_superuser_required
+def manage_student(request, assignment_id, student_id):
+    student = get_object_or_404(
+        get_user_model().objects.filter(is_student=True),
+        id=student_id,
+    )
+    assignment = get_object_or_404(Assignment, id=assignment_id)
+    data = assignment.find_student_data(student=student)
+    form = PerStudentDataForm(instance=data)
+    if request.method == "POST":
+        form = PerStudentDataForm(data=request.POST, instance=data)
+        if form.is_valid():
+            form.save()
+            return redirect("assignments:manage_students", assignment_id)
+    return render(
+        request,
+        "assignments/manage_student.html",
+        {"form": form, "user": student, "assignment": assignment},
+    )
+
+
 @teacher_or_superuser_required
 def manage_grader_view(request, assignment_id):
     """Uploads a grader for an assignment
@@ -535,6 +569,8 @@ def submit_view(request, assignment_id):
         raise http.Http404
 
     student = request.user
+    if not assignment.within_submission_limit(student):
+        return http.HttpResponseForbidden("Submission limit exceeded")
 
     submissions = Submission.objects.filter(student=student, assignment=assignment)
     latest_submission = submissions.latest() if submissions else None
@@ -704,6 +740,8 @@ def quiz_view(request, assignment_id):
         raise http.Http404
 
     student = request.user
+    if not assignment.within_submission_limit(student):
+        return http.HttpResponseForbidden("Submission limit exceeded")
 
     submissions = Submission.objects.filter(student=student, assignment=assignment)
     latest_submission = submissions.latest() if submissions else None
@@ -756,8 +794,9 @@ def quiz_view(request, assignment_id):
 
                     run_submission.delay(submission.id)
                     return redirect("assignments:quiz", assignment.id)
-                else:
-                    text_errors = "Submission too large"
+
+            else:
+                text_errors = "Submission too large"
 
     quiz_color = assignment.quiz_issues_for_student(request.user) and assignment.quiz_action == "1"
 

tin/apps/submissions/models.py

@@ -199,7 +199,7 @@ def file_text(self):
             return None
 
         try:
-            with open(self.backup_file_path) as f:
+            with open(self.backup_file_path, encoding="utf-8") as f:
                 file_text = f.read()
         except OSError:
             file_text = "[Error accessing submission file]"

tin/apps/submissions/tasks.py

@@ -31,7 +31,7 @@ def truncate_output(text, field_name):
 
 
 @shared_task
-def run_submission(submission_id):
+def run_submission(submission_id: int) -> None:
     submission = Submission.objects.get(id=submission_id)
 
     try:
@@ -80,7 +80,8 @@ def run_submission(submission_id):
                 "wrappers",
                 folder_name,
                 f"{submission.assignment.language}.txt",
-            )
+            ),
+            encoding="utf-8",
         ) as wrapper_file:
             wrapper_text = wrapper_file.read().format(
                 has_network_access=bool(submission.assignment.has_network_access),

tin/static/css/base.css

@@ -150,23 +150,26 @@ ul.no-list {
 ul#course-list,
 ul#assignment-list,
 ul#venv-list,
-ul#archive-list {
+ul#archive-list,
+ul.linebreak-list {
   padding-left: 0px;
   margin-left: 0px;
 }
 
 ul#course-list > li,
 ul#assignment-list > li,
 ul#venv-list > li,
-ul#archive-list > li {
+ul#archive-list > li,
+ul.linebreak-list > li {
   display: flex;
   padding: 10px 0px;
   border-top: 1px solid lightgray;
 }
 
 ul#course-list > li:last-child,
 ul#assignment-list > li:last-child,
-ul#venv-list > li:last-child {
+ul#venv-list > li:last-child,
+ul.linebreak-last > li:last-child {
   border-bottom: 1px solid lightgray;
 }
 
@@ -204,7 +207,8 @@ ul#venv-list > li .left {
 ul#course-list > li .right,
 ul#assignment-list > li .right,
 ul#venv-list > li .right,
-ul#archive-list > li .right {
+ul#archive-list > li .right,
+ul.linebreak-list > li .right {
   margin-left: auto;
   flex: 0 0 auto;
   text-align: right;