test(model-usage): cover pick_current_model and latest_day_cost coercion

coder999999999 · vincentkoc · commit 11bb5719caea · 2026-06-23T16:15:33.000+08:00
diff --git a/skills/model-usage/scripts/test_model_usage.py b/skills/model-usage/scripts/test_model_usage.py
@@ -7,7 +7,14 @@
 from datetime import date, timedelta
 from unittest import TestCase, main
 
-from model_usage import aggregate_costs, coerce_finite_cost, filter_by_days, positive_int
+from model_usage import (
+    aggregate_costs,
+    coerce_finite_cost,
+    filter_by_days,
+    latest_day_cost,
+    pick_current_model,
+    positive_int,
+)
 
 
 class TestModelUsage(TestCase):
@@ -88,6 +95,58 @@ def test_aggregate_costs_ignores_bool_and_non_finite(self):
         # NaN/Infinity must not poison the total; bool must not add 1.0.
         self.assertEqual(totals, {"claude-sonnet-4-6": 3.25})
 
+    def test_pick_current_model_scores_numeric_string_costs(self):
+        # model-b's cost is a numeric string; it must still win on highest cost.
+        entries = [
+            {
+                "date": "2026-05-25",
+                "modelBreakdowns": [
+                    {"modelName": "model-a", "cost": 1.0},
+                    {"modelName": "model-b", "cost": "5.0"},
+                ],
+            }
+        ]
+        model, day = pick_current_model(entries)
+        self.assertEqual(model, "model-b")
+        self.assertEqual(day, "2026-05-25")
+
+    def test_pick_current_model_ignores_bool_and_non_finite(self):
+        # Only model-a has a usable cost; bool and NaN must not be scored.
+        entries = [
+            {
+                "date": "2026-05-25",
+                "modelBreakdowns": [
+                    {"modelName": "model-a", "cost": 2.0},
+                    {"modelName": "model-b", "cost": True},
+                    {"modelName": "model-c", "cost": float("nan")},
+                ],
+            }
+        ]
+        model, _day = pick_current_model(entries)
+        self.assertEqual(model, "model-a")
+
+    def test_latest_day_cost_accepts_numeric_string(self):
+        entries = [
+            {
+                "date": "2026-05-25",
+                "modelBreakdowns": [{"modelName": "model-a", "cost": "2.50"}],
+            }
+        ]
+        day, cost = latest_day_cost(entries, "model-a")
+        self.assertEqual(day, "2026-05-25")
+        self.assertEqual(cost, 2.50)
+
+    def test_latest_day_cost_rejects_non_finite(self):
+        entries = [
+            {
+                "date": "2026-05-25",
+                "modelBreakdowns": [{"modelName": "model-a", "cost": float("inf")}],
+            }
+        ]
+        day, cost = latest_day_cost(entries, "model-a")
+        self.assertEqual(day, "2026-05-25")
+        self.assertIsNone(cost)
+
 
 if __name__ == "__main__":
     main()
