brmbar-github/brmbar3/tests/test_currency_rates.py

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5.1 KiB
Python

# tests/test_currency_rates.py
import pytest
from contextlib import closing
import math
from decimal import Decimal
# Assuming brmbar modules are importable via PYTHONPATH or package structure
from brmbar.Database import Database
from brmbar.Currency import Currency
# --- Fixtures ---
@pytest.fixture(scope="module")
def db_connection():
"""Provides a database connection for the test module."""
# Ensure dbname is correct for your test environment
# This connects using the default user/db setup expected by the entrypoint
db = Database("dbname=brmbar")
yield db
# Explicitly close the connection if Database doesn't handle it
if hasattr(db, 'db_conn') and db.db_conn and not db.db_conn.closed:
db.db_conn.close()
@pytest.fixture(scope="module")
def all_currencies(db_connection):
"""Fetches all currency objects from the database."""
# Ensure the connection is open before using it
if not db_connection or not hasattr(db_connection, 'db_conn') or db_connection.db_conn.closed:
pytest.skip("Database connection not available for fetching currencies") # Skip if DB setup failed
currencies_data = []
try:
with closing(db_connection.db_conn.cursor()) as cur:
# Added ORDER BY for consistent test order and reliable pairing
cur.execute("SELECT id, name FROM currencies ORDER BY id")
currencies_data = cur.fetchall()
except Exception as e:
pytest.fail(f"Failed to fetch currencies from DB: {e}")
if not currencies_data:
pytest.skip("No currencies found in the database to test")
# Ensure db_connection is passed correctly to Currency constructor
return [Currency(db_connection, id, name) for id, name in currencies_data]
# --- Test Function ---
# Helper to run a rate function and capture result or exception
def get_rate_or_exception(currency_from, currency_to, method_name):
method = getattr(currency_from, method_name)
try:
# Ensure currency_to is passed to the method
return method(currency_to), None
except (RuntimeError, NameError) as e: # Add other expected exceptions if any
return None, e
except Exception as e: # Catch unexpected exceptions during rate calculation
pytest.fail(f"Unexpected exception in {method_name} for {currency_from.name}->{currency_to.name}: {type(e).__name__}: {e}")
def test_rate_comparison(all_currencies):
"""Compares the results of rates() and rates2() for all currency pairs."""
if not all_currencies:
pytest.skip("Skipping test as no currencies were fetched.")
# Iterate through all pairs of currencies
for c1 in all_currencies:
for c2 in all_currencies:
# Ensure c1 and c2 are actual Currency objects (good practice, though should be true)
assert isinstance(c1, Currency), f"Param c1 is not a Currency object: {c1}"
assert isinstance(c2, Currency), f"Param c2 is not a Currency object: {c2}"
rates1, exc1 = get_rate_or_exception(c1, c2, 'rates')
rates2, exc2 = get_rate_or_exception(c1, c2, 'rates2')
if exc1 or exc2:
# If one raised an exception, the other must raise the *same* type and message
assert exc1 is not None and exc2 is not None, \
f"Mismatch in exceptions for {c1.name}->{c2.name}. rates(): {exc1}, rates2(): {exc2}"
assert type(exc1) == type(exc2), \
f"Exception type mismatch for {c1.name}->{c2.name}: {type(exc1).__name__} vs {type(exc2).__name__}"
assert str(exc1) == str(exc2), \
f"Exception message mismatch for {c1.name}->{c2.name}: '{exc1}' vs '{exc2}'"
# If exceptions match, the test passes for this pair
else:
# If neither raised an exception, compare rates using pytest.approx
assert rates1 is not None and rates2 is not None, \
f"Expected rates but got None (and no exception) for {c1.name}->{c2.name}"
# Check if rates are tuples of two numbers (buy, sell)
assert isinstance(rates1, tuple) and len(rates1) == 2, f"rates() result not a tuple(buy, sell) for {c1.name}->{c2.name}: {rates1}"
assert isinstance(rates2, tuple) and len(rates2) == 2, f"rates2() result not a tuple(buy, sell) for {c1.name}->{c2.name}: {rates2}"
assert all(isinstance(r, (int, float, Decimal)) for r in rates1), f"rates() values not numeric for {c1.name}->{c2.name}: {rates1}"
assert all(isinstance(r, (int, float, Decimal)) for r in rates2), f"rates2() values not numeric for {c1.name}->{c2.name}: {rates2}"
# Compare buy and sell rates approximately
# Use rel= or abs= if default tolerance is not suitable
assert rates1[0] == pytest.approx(rates2[0]), \
f"Buy rate mismatch for {c1.name}->{c2.name}: {rates1[0]} vs {rates2[0]}"
assert rates1[1] == pytest.approx(rates2[1]), \
f"Sell rate mismatch for {c1.name}->{c2.name}: {rates1[1]} vs {rates2[1]}"