From 38bef98ab1964bc9365d17c4a5ca17cdbd32673b Mon Sep 17 00:00:00 2001
From: Tyler Hoang <tyler@tylerhoang.xyz>
Date: Mon, 18 May 2026 02:34:46 -0700
Subject: fix: correct historical ratios share and debt inputs

---
 backend/tests/test_api.py | 96 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

(limited to 'backend/tests/test_api.py')

diff --git a/backend/tests/test_api.py b/backend/tests/test_api.py
index 94c9c20..d0aafa4 100644
--- a/backend/tests/test_api.py
+++ b/backend/tests/test_api.py
@@ -993,6 +993,102 @@ def test_compute_historical_ratios_margins(monkeypatch) -> None:
     assert result["price_to_sales"] == [None, None, None, None]
 
 
+def test_compute_historical_ratios_uses_period_share_counts_oldest_first(monkeypatch) -> None:
+    clear_service_caches()
+    monkeypatch.setattr(
+        data_service,
+        "get_income_statement",
+        lambda symbol, quarterly=False: annual_frame(
+            {
+                "Total Revenue": [40.0, 40.0, 40.0, 40.0],
+                "Gross Profit": [20.0, 20.0, 20.0, 20.0],
+                "Operating Income": [15.0, 15.0, 15.0, 15.0],
+                "Net Income": [10.0, 10.0, 10.0, 10.0],
+                "EBITDA": [2_000_000.0, 2_000_000.0, 2_000_000.0, 2_000_000.0],
+            }
+        ),
+    )
+    monkeypatch.setattr(
+        data_service,
+        "get_balance_sheet",
+        lambda symbol, quarterly=False: annual_frame(
+            {
+                "Stockholders Equity": [20.0, 20.0, 20.0, 20.0],
+                "Total Assets": [50.0, 50.0, 50.0, 50.0],
+                "Total Debt": [100_000.0, 100_000.0, 100_000.0, 100_000.0],
+                "Current Assets": [10.0, 10.0, 10.0, 10.0],
+                "Current Liabilities": [5.0, 5.0, 5.0, 5.0],
+                "Cash And Cash Equivalents": [0.0, 0.0, 0.0, 0.0],
+                "Ordinary Shares Number": [10.0, 20.0, 40.0, 80.0],
+            }
+        ),
+    )
+    monkeypatch.setattr(data_service, "get_cash_flow", lambda symbol, quarterly=False: pd.DataFrame())
+    monkeypatch.setattr(data_service, "get_shares_outstanding", lambda symbol: 999.0)
+    monkeypatch.setattr(
+        data_service,
+        "get_price_history",
+        lambda symbol, period="5y": [
+            {"date": "2024-09-30", "close": 10.0},
+            {"date": "2023-09-30", "close": 10.0},
+            {"date": "2022-09-30", "close": 10.0},
+            {"date": "2021-09-30", "close": 10.0},
+        ],
+    )
+
+    result = data_service.compute_historical_ratios("AAPL")
+
+    assert result["trailing_pe"] == [80.0, 40.0, 20.0, 10.0]
+    assert result["price_to_book"] == [40.0, 20.0, 10.0, 5.0]
+    assert result["price_to_sales"] == [20.0, 10.0, 5.0, 2.5]
+
+
+def test_compute_historical_ratios_uses_long_term_debt_fallback(monkeypatch) -> None:
+    clear_service_caches()
+    monkeypatch.setattr(
+        data_service,
+        "get_income_statement",
+        lambda symbol, quarterly=False: annual_frame(
+            {
+                "Total Revenue": [5_000_000.0, 5_000_000.0, 5_000_000.0, 5_000_000.0],
+                "Gross Profit": [2_500_000.0, 2_500_000.0, 2_500_000.0, 2_500_000.0],
+                "Operating Income": [2_100_000.0, 2_100_000.0, 2_100_000.0, 2_100_000.0],
+                "Net Income": [1_000_000.0, 1_000_000.0, 1_000_000.0, 1_000_000.0],
+                "EBITDA": [2_000_000.0, 2_000_000.0, 2_000_000.0, 2_000_000.0],
+            }
+        ),
+    )
+    monkeypatch.setattr(
+        data_service,
+        "get_balance_sheet",
+        lambda symbol, quarterly=False: annual_frame(
+            {
+                "Stockholders Equity": [4_000_000.0, 4_000_000.0, 4_000_000.0, 4_000_000.0],
+                "Total Assets": [8_000_000.0, 8_000_000.0, 8_000_000.0, 8_000_000.0],
+                "Long Term Debt And Capital Lease Obligation": [2_000_000.0, 2_000_000.0, 2_000_000.0, 2_000_000.0],
+                "Cash And Cash Equivalents": [1_000_000.0, 1_000_000.0, 1_000_000.0, 1_000_000.0],
+                "Ordinary Shares Number": [1_000_000.0, 1_000_000.0, 1_000_000.0, 1_000_000.0],
+            }
+        ),
+    )
+    monkeypatch.setattr(data_service, "get_cash_flow", lambda symbol, quarterly=False: pd.DataFrame())
+    monkeypatch.setattr(data_service, "get_shares_outstanding", lambda symbol: None)
+    monkeypatch.setattr(
+        data_service,
+        "get_price_history",
+        lambda symbol, period="5y": [
+            {"date": "2024-09-30", "close": 10.0},
+            {"date": "2023-09-30", "close": 10.0},
+            {"date": "2022-09-30", "close": 10.0},
+            {"date": "2021-09-30", "close": 10.0},
+        ],
+    )
+
+    result = data_service.compute_historical_ratios("AAPL")
+
+    assert result["ev_to_ebitda"] == [5.5, 5.5, 5.5, 5.5]
+
+
 def test_compute_historical_ratios_empty_income(monkeypatch) -> None:
     clear_service_caches()
     monkeypatch.setattr(data_service, "get_income_statement", lambda symbol, quarterly=False: pd.DataFrame())
-- 
cgit v1.3-2-g0d8e