testing new features

tests/test_model.py

@@ -3,6 +3,7 @@ from pathlib import Path
 from cashflow_model import (
     Account,
     Asset,
+    ExchangeRate,
     FinancialModel,
     ForecastScenario,
     Liability,
@@ -42,6 +43,32 @@ class TestTransaction:
 
 
 class TestFinancialModel:
+    def test_default_base_currency(self):
+        model = FinancialModel()
+        assert model.base_currency == "RUB"
+
+    def test_base_currency_roundtrip(self, tmp_path: Path):
+        model = FinancialModel(base_currency="EUR")
+        p = tmp_path / "model.json"
+        model.save(p)
+        loaded = FinancialModel.load(p)
+        assert loaded.base_currency == "EUR"
+
+    def test_base_currency_backward_compat(self, tmp_path: Path):
+        import json
+        p = tmp_path / "legacy.json"
+        with open(p, "w") as f:
+            json.dump({"accounts": []}, f)
+        loaded = FinancialModel.load(p)
+        assert loaded.base_currency == "RUB"
+
+    def test_exchange_rates_default(self):
+        model = FinancialModel()
+        assert len(model.exchange_rates) == 1
+        assert model.exchange_rates[0].from_currency == "USD"
+        assert model.exchange_rates[0].to_currency == "RUB"
+        assert model.exchange_rates[0].rate == 80.0
+
     def test_save_load(self, tmp_path: Path):
         model = FinancialModel()
         model.accounts.append(Account(name="Test", balance=100.0))
@@ -61,6 +88,8 @@ class TestFinancialModel:
         d = model.to_dict()
         assert d["accounts"] == []
         assert d["transactions"] == []
+        assert d["base_currency"] == "RUB"
+        assert "exchange_rates" in d
 
     def test_all_entities_roundtrip(self, tmp_path: Path):
         model = FinancialModel(
@@ -70,6 +99,7 @@ class TestFinancialModel:
             assets=[Asset(name="Stock", value=1000.0)],
             liabilities=[Liability(name="Loan", balance=500.0, interest=5.0, payment=100.0)],
             scenarios=[ForecastScenario(name="test")],
+            exchange_rates=[ExchangeRate(from_currency="USD", to_currency="RUB", rate=80.0)],
         )
         p = tmp_path / "full.json"
         model.save(p)
@@ -80,3 +110,4 @@ class TestFinancialModel:
         assert len(loaded.assets) == 1
         assert len(loaded.liabilities) == 1
         assert len(loaded.scenarios) == 1
+        assert len(loaded.exchange_rates) == 1