Add test for grants review score_range annotation

Test covers score_range calculation including:
- Multiple different scores (max-min range)
- All same scores (zero range)
- Single score (zero range)
- No scores (None)
- Two different scores

Co-authored-by: Ester Beltrami <estyxx@users.noreply.github.com>

Author: github-actions[bot]

backend/reviews/tests/test_admin.py

@@ -191,6 +191,99 @@ def test_grants_review_scores(rf, scores, avg):
     assert grant_to_check.score == avg
 
 
+@pytest.mark.parametrize(
+    "scores, expected_score_range",
+    [
+        # Multiple different scores: range = max - min = 2 - (-2) = 4
+        (
+            [
+                {"user": 0, "score": 2},
+                {"user": 1, "score": 2},
+                {"user": 2, "score": 2},
+                {"user": 3, "score": -1},
+                {"user": 4, "score": -2},
+            ],
+            4.0,
+        ),
+        # All same scores: range = -2 - (-2) = 0
+        (
+            [
+                {"user": 0, "score": -2},
+                {"user": 1, "score": -2},
+                {"user": 2, "score": -2},
+                {"user": 3, "score": -2},
+                {"user": 4, "score": -2},
+            ],
+            0.0,
+        ),
+        # Single score: range = 1 - 1 = 0
+        (
+            [
+                {"user": 0, "score": 1},
+            ],
+            0.0,
+        ),
+        # No scores: range = None
+        ([], None),
+        # Two different scores: range = 1 - (-1) = 2
+        (
+            [
+                {"user": 0, "score": 1},
+                {"user": 1, "score": -1},
+            ],
+            2.0,
+        ),
+    ],
+)
+def test_grants_review_score_range(rf, scores, expected_score_range):
+    conference = ConferenceFactory()
+    review_session = ReviewSessionFactory(
+        conference=conference,
+        session_type=ReviewSession.SessionType.GRANTS,
+        status=ReviewSession.Status.COMPLETED,
+    )
+
+    users = UserFactory.create_batch(10, is_staff=True, is_superuser=True)
+    all_scores = {
+        -2: AvailableScoreOptionFactory(
+            review_session=review_session, numeric_value=-2, label="Rejected"
+        ),
+        -1: AvailableScoreOptionFactory(
+            review_session=review_session, numeric_value=-1, label="Not convinced"
+        ),
+        0: AvailableScoreOptionFactory(
+            review_session=review_session, numeric_value=0, label="Maybe"
+        ),
+        1: AvailableScoreOptionFactory(
+            review_session=review_session, numeric_value=1, label="Yes"
+        ),
+        2: AvailableScoreOptionFactory(
+            review_session=review_session, numeric_value=2, label="Absolutely"
+        ),
+    }
+
+    grant = GrantFactory(conference=conference)
+    for score in scores:
+        UserReviewFactory(
+            review_session=review_session,
+            grant=grant,
+            user=users[score["user"]],
+            score=all_scores[score["score"]],
+        )
+
+    request = rf.get("/")
+    request.user = users[5]
+
+    admin = ReviewSessionAdmin(ReviewSession, AdminSite())
+    response = admin._review_grants_recap_view(request, review_session)
+    context_data = response.context_data
+    items = context_data["items"]
+    grant_to_check = next(item for item in items if item.id == grant.id)
+
+    assert grant_to_check.id == grant.id
+    assert grant_to_check.score_range == expected_score_range
+
+
 def test_review_start_view_when_no_items_are_left(rf, mocker):
     mock_messages = mocker.patch("reviews.admin.messages")