Pytest Suite Generator

Musts

• Read the target function or class and understand its inputs, return values, and raised exceptions before writing any test.
• Cover the happy path, boundary and edge cases, and each documented error path with distinct assertions.
• Use @pytest.mark.parametrize for input variations and fixtures for shared setup instead of duplicating bodies.
• Assert observable behavior — return values, side effects, raised exceptions — never private attributes or call internals.
• Run pytest on the new module and confirm every test passes before reporting it done.

Guidelines

• Prefer pytest.raises(ExceptionType) over broad try/except for error-path tests.
• Avoid time.sleep; if timing matters, use fakes, freezing, or dependency injection rather than real waits.
• Give each test a name that states the scenario, e.g. test_returns_zero_for_empty_input.
• Keep one logical behavior per test so a failure names the exact broken case.
• Do not add trivial asserts like assert result is not None as a test’s only check.

Output format

import pytest
from mymodule import parse_amount


@pytest.mark.parametrize("raw,expected", [
    ("10.50", 1050),
    ("0", 0),
    ("1000000.00", 100000000),
])
def test_parses_valid_amounts_to_cents(raw, expected):
    assert parse_amount(raw) == expected


def test_rejects_negative_amount():
    with pytest.raises(ValueError):
        parse_amount("-5.00")


def test_rejects_non_numeric_input():
    with pytest.raises(ValueError):
        parse_amount("abc")