Files
ProgressQuest-cli/tests/test_random.py
T
Dash 9c44d69633 random: port Alea, one generator per character
pqcli used Python's global Mersenne Twister, seeded once from the clock.
Upstream uses Johannes Baagøe's Alea, with Random(n) = uint32() % n, and
keeps the generator state with each character. The port matches the JS
output bit for bit, including UTF-16 seeding of non-BMP characters.

Each Player now owns an Alea that is pickled with the save, and
Simulation.tick draws from it. Saves without one get a fresh generator.
As upstream does, a new character's game continues from the state the
kept stat roll was made from.

The parity traces are re-recorded, since every random number changes.
2026-10-17 15:55:50 +02:00

89 lines
2.3 KiB
Python

import pickle
import pytest
from pqcli import random
from pqcli.random import Alea
# First outputs and resulting state of upstream's JS Alea(seed).uint32()
VECTORS = {
"alpha": (
[3768637044, 756790225, 3147161637, 1726577786, 279486812],
(0.732755669625476, 0.4020002172328532, 0.06507309433072805, 368555),
),
"": (
[715789690, 2091287642, 486307, 3866591158, 760028033],
(
0.00011322717182338238,
0.9002609080635011,
0.17695781611837447,
1018452,
),
),
"1697543210123": (
[3110287155, 2843160345, 1794106530, 2361562046, 1804721005],
(
0.41772297816351056,
0.5498440111987293,
0.42019435320980847,
1384612,
),
),
# Mash hashes UTF-16 code units, so the dragon counts as two
"Ünïcødé 🐉": (
[4162081648, 198215584, 541466577, 6418444, 2254846220],
(
0.12607001163996756,
0.0014944104477763176,
0.5249972967430949,
96530,
),
),
}
@pytest.mark.parametrize("seed", VECTORS)
def test_alea_matches_upstream(seed: str) -> None:
first, state = VECTORS[seed]
rng = Alea(seed)
assert [rng.uint32() for _ in first] == first
assert rng.state() == state
def test_alea_state_round_trip() -> None:
rng = Alea("alpha")
rng.uint32()
copy = Alea.from_state(rng.state())
assert [copy.uint32() for _ in range(100)] == [
rng.uint32() for _ in range(100)
]
def test_alea_pickles_with_its_state() -> None:
rng = Alea("alpha")
rng.uint32()
copy = pickle.loads(pickle.dumps(rng))
assert copy.state() == rng.state()
def test_unseeded_alea_differs() -> None:
assert Alea().state() != Alea("alpha").state()
def test_below_is_uint32_modulo() -> None:
# Random(n) = seed.uint32() % n
random.seed("alpha")
assert [random.below(1000) for _ in range(5)] == [
n % 1000 for n in VECTORS["alpha"][0]
]
def test_using_restores_previous_generator() -> None:
random.seed("outer")
expected = Alea("outer").uint32() % 1000
inner = Alea("inner")
with random.using(inner):
random.below(10)
assert inner.state() != Alea("inner").state()
assert random.below(1000) == expected