room_price_calc/test_roundtrip.py

import random
import warnings
import pytest
from app import app, SERVICES, URL_PREFIX

TOLERANCE = 0.02


@pytest.fixture
def client():
    app.config['TESTING'] = True
    with app.test_client() as c:
        yield c


def _call(client, endpoint, service, amount):
    resp = client.post(f'{URL_PREFIX}/{endpoint}', json={'service': service, 'amount': amount})
    assert resp.status_code == 200, resp.get_json()
    return resp.get_json()


def _near(a, b):
    return abs(float(a) - float(b)) <= TOLERANCE


def _check(label, a, b):
    diff = abs(float(a) - float(b))
    if diff > TOLERANCE:
        warnings.warn(f"{label}: {float(a):.4f} vs {float(b):.4f} (diff={diff:.4f})", stacklevel=2)


def test_net_retail_roundtrip(client):
    net = random.uniform(58, 258)

    for service_key in SERVICES:
        r1 = _call(client, 'net_to_retail', service_key, net)
        retail = float(r1['retail'])
        r2 = _call(client, 'retail_to_net', service_key, retail)

        _check(f'[{service_key}] list',   r1['list'], r2['list'])
        _check(f'[{service_key}] net',    net,        r2['net'])

        shared_keys = set(r1.get('details', {})) & set(r2.get('details', {}))
        for k in shared_keys:
            _check(f'[{service_key}] details.{k}', r1['details'][k], r2['details'][k])