From 90b9f6db1e4ec8e45ff4fb3dd3ba36d34943c19d Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Sat, 15 Aug 2026 23:36:02 +0100
Subject: [PATCH] Scope snapshot tests to numeric hardening

---
 .../tests/test_snapshot_invalid_numerics.py   | 54 +++++++++----------
 1 file changed, 24 insertions(+), 30 deletions(-)

diff --git a/backend/services/infonet/tests/test_snapshot_invalid_numerics.py b/backend/services/infonet/tests/test_snapshot_invalid_numerics.py
index d727e16..cf2f7a7 100644
--- a/backend/services/infonet/tests/test_snapshot_invalid_numerics.py
+++ b/backend/services/infonet/tests/test_snapshot_invalid_numerics.py
@@ -1,14 +1,22 @@
-"""Regression coverage for malformed/non-finite market snapshot inputs."""
+"""Regression coverage for malformed/non-finite market snapshot numerics."""
 
 import math
+from typing import Any
 
 import pytest
 
-from services.infonet.markets.snapshot import build_snapshot, find_snapshot
+from services.infonet.markets.snapshot import build_snapshot
 
 
-def _prediction(node, side, stake, *, timestamp, sequence):
-    payload = {"market_id": "m1", "side": side}
+def _prediction(
+    node: str,
+    side: str,
+    stake: Any,
+    *,
+    timestamp: float,
+    sequence: int,
+) -> dict[str, Any]:
+    payload: dict[str, Any] = {"market_id": "m1", "side": side}
     if stake is not None:
         payload["stake_amount"] = stake
     return {
@@ -20,10 +28,11 @@ def _prediction(node, side, stake, *, timestamp, sequence):
     }
 
 
-def test_nonfinite_paid_stake_does_not_poison_snapshot():
+@pytest.mark.parametrize("invalid_stake", [float("nan"), float("inf"), "not-a-number", -1.0, 0.0])
+def test_invalid_paid_stake_does_not_poison_or_count_snapshot(invalid_stake: Any) -> None:
     chain = [
         _prediction("alice", "yes", None, timestamp=100.0, sequence=1),
-        _prediction("mallory", "no", float("inf"), timestamp=101.0, sequence=2),
+        _prediction("mallory", "no", invalid_stake, timestamp=101.0, sequence=2),
     ]
 
     snapshot = build_snapshot("m1", chain, frozen_at=200.0)
@@ -35,36 +44,21 @@ def test_nonfinite_paid_stake_does_not_poison_snapshot():
     assert all(math.isfinite(v) for v in snapshot["frozen_probability_state"].values())
 
 
-def test_malformed_ordering_metadata_does_not_break_snapshot_build():
+def test_finite_numeric_string_stake_is_preserved() -> None:
     chain = [
-        _prediction("alice", "yes", 5.0, timestamp="bad", sequence="bad"),
-        _prediction("bob", "no", 5.0, timestamp=100.0, sequence=1),
+        _prediction("alice", "yes", "2.5", timestamp=100.0, sequence=1),
+        _prediction("bob", "no", "7.5", timestamp=101.0, sequence=2),
     ]
 
-    snapshot = build_snapshot("m1", chain, frozen_at=200.0)
+    snapshot = build_snapshot("m1", chain, frozen_at="200.5")
 
     assert snapshot["frozen_participant_count"] == 2
     assert snapshot["frozen_total_stake"] == 10.0
-    assert snapshot["frozen_probability_state"] == {"yes": 0.5, "no": 0.5}
+    assert snapshot["frozen_probability_state"] == {"yes": 0.25, "no": 0.75}
+    assert snapshot["frozen_at"] == 200.5
 
 
-def test_invalid_snapshot_ordering_does_not_outrank_valid_snapshot():
-    invalid = {
-        "event_type": "market_snapshot",
-        "timestamp": "bad",
-        "sequence": "bad",
-        "payload": {"market_id": "m1", "marker": "invalid"},
-    }
-    valid = {
-        "event_type": "market_snapshot",
-        "timestamp": 100.0,
-        "sequence": 1,
-        "payload": {"market_id": "m1", "marker": "valid"},
-    }
-
-    assert find_snapshot("m1", [invalid, valid])["marker"] == "valid"
-
-
-def test_nonfinite_frozen_at_is_rejected():
+@pytest.mark.parametrize("invalid_frozen_at", [float("nan"), float("inf"), "not-a-time"])
+def test_nonfinite_or_malformed_frozen_at_is_rejected(invalid_frozen_at: Any) -> None:
     with pytest.raises(ValueError, match="frozen_at must be finite"):
-        build_snapshot("m1", [], frozen_at=float("nan"))
+        build_snapshot("m1", [], frozen_at=invalid_frozen_at)