Split flow.py to simulate.py and model.py

model.py should be a file containing only dataclasses to model finance.
simulate.py should take care of the simulation of that finance data to
create a financial forecast.

1 files changed, 48 insertions, 0 deletions

diff --git a/finance/test_simulate.py b/finance/test_simulate.py
new file mode 100644
index 0000000..3b79c99
--- /dev/null
+++ b/finance/test_simulate.py
@@ -0,0 +1,48 @@
+from datetime import datetime
+from decimal import Decimal
+
+from finance.model import Flow
+from finance.simulate import simulate, integrate
+
+
+def test_flow_integration() -> None:
+    fl = Flow(
+        amount=Decimal(3000.0),
+        since=datetime(2023, 1, 1),
+        until=datetime(2026, 1, 5),
+    )
+
+    tests = (
+        (datetime(2024, 3, 12), datetime(2024, 4, 2), Decimal(3000.0)),
+        (datetime(2024, 3, 1), datetime(2024, 3, 15), Decimal(3000.0)),
+        (datetime(2024, 2, 25), datetime(2024, 3, 1), Decimal(3000.0)),
+        (datetime(2024, 2, 25), datetime(2024, 6, 12), Decimal(12000.0)),
+        (datetime(2022, 1, 5), datetime(2022, 9, 14), Decimal(0.0)),
+        (datetime(2022, 1, 5), datetime(2023, 1, 1), Decimal(3000.0)),
+        (datetime(2022, 7, 4), datetime(2024, 12, 8), Decimal(72000.0)),
+        (datetime(2025, 11, 4), datetime(2026, 5, 9), Decimal(6000.0)),
+        (datetime(2026, 1, 5), datetime(2027, 1, 1), Decimal(0.0)),
+        (datetime(2027, 5, 28), datetime(2028, 7, 7), Decimal(0.0)),
+    )
+
+    for test in tests:
+        assert integrate(fl, start=test[0], end=test[1]) == test[2]
+
+
+def test_simulate() -> None:
+    flows = (Flow(amount=Decimal(100.0), since=None, until=None),)
+
+    simulated = simulate(
+        start=datetime(2024, 1, 1),
+        end=datetime(2024, 4, 1),
+        flows=flows,
+    )
+
+    expected = [
+        (datetime(2024, 1, 1), Decimal(100.0)),
+        (datetime(2024, 2, 1), Decimal(200.0)),
+        (datetime(2024, 3, 1), Decimal(300.0)),
+        (datetime(2024, 4, 1), Decimal(400.0)),
+    ]
+
+    assert simulated == expected