Instruction file imported from yashovardhan99/niveshpy (.github/instructions/tests.instructions.md). Copyright stays with the author.

NiveshPy Test Conventions

Tests mirror the niveshpy/ package layout. There are three distinct test layers, each with its own fixture pattern. Pick the one matching the layer you're testing — do not mix them.

1. Service tests — tests/services/**

Pure unit tests against niveshpy/services/*. Inject the Mock*Repository classes from tests/services/conftest.py; never construct a SqliteDatabase here.

from niveshpy.services.account import AccountService
from tests.services.conftest import MockAccountRepository

@pytest.fixture
def account_service() -> AccountService:
    return AccountService(account_repository=MockAccountRepository())

• The mocks implement the same domain/repositories/* Protocol as the real SQLite repos, so service code is exercised unchanged.
• Group tests under class TestMethodName: (one class per service method) — see tests/services/test_account_service.py for the canonical layout.
• If you add a new method to a repository protocol, also add it to the matching Mock*Repository in tests/services/conftest.py, or service tests will fail at runtime.

2. Repository / infrastructure tests — tests/infrastructure/sqlite/**

Use the db fixture from tests/conftest.py, which builds a fresh in-memory SqliteDatabase(db_path=Path(":memory:")) and runs migrations:

def test_insert_account(db):
    repo = SqliteAccountRepository(db)
    ...

• One db per test (function scope) — do not share state across tests.
• Test SQL/row-mapping behavior here, not service logic.

3. CLI integration tests — tests/cli/**

Use the cli_scenario + runner fixtures from tests/cli/conftest.py. The cli_in_memory_db autouse fixture monkeypatches Application.db to an in-memory database, so every cli_scenario.invoke([...]) call hits a clean, isolated DB.

def test_accounts_add(cli_scenario):
    account_id = cli_scenario.add_account("HDFC Savings", "HDFC Bank")
    accounts = cli_scenario.invoke_json(["accounts", "list"])
    assert accounts[0]["id"] == account_id

• Prefer the CliScenario helpers (add_account, add_security, add_transaction, invoke_json) over hand-rolling Click invocations — they assert exit codes and parse JSON output uniformly.
• Pass --no-input to commands that prompt; the runner won't supply stdin.
• Use expected_exit_code=N on invoke() for negative-path tests.

General Conventions

• Filesystem isolation: the session-wide autouse mock_platformdirs fixture in tests/conftest.py redirects platformdirs.user_data_path to tmp_path_factory. Never hit the real user data dir.
• assert is allowed in tests/* (ruff S101 is disabled there). Plain assert ... is preferred over unittest-style asserts.
• Naming: test_<module>.py mirroring the source module (e.g., niveshpy/services/account.py → tests/services/test_account_service.py).
• Decimal money: in fixtures, pass amounts as strings (e.g., "1000.50") so Decimal parsing is exercised. Never use float.
• Exceptions: assert against the specific subclass from niveshpy/exceptions.py (e.g., pytest.raises(InvalidInputError)), not bare Exception.
• Running tests:

  uv run coverage run -m pytest                  # full suite
  uv run pytest tests/services/test_account_service.py::TestListAccounts
  uv run pytest -k "test_account_create"