mtg_python_deckbuilder/code/tests/test_random_util.py

37 lines
1.1 KiB
Python

from __future__ import annotations
from random_util import derive_seed_from_string, set_seed, get_random, generate_seed
def test_derive_seed_from_string_stable():
# Known value derived from SHA-256('test-seed') first 8 bytes masked to 63 bits
assert derive_seed_from_string('test-seed') == 6214070892065607348
# Int passthrough-like behavior (normalized to positive 63-bit)
assert derive_seed_from_string(42) == 42
assert derive_seed_from_string(-42) == 42
def test_set_seed_deterministic_stream():
r1 = set_seed('alpha')
r2 = set_seed('alpha')
seq1 = [r1.random() for _ in range(5)]
seq2 = [r2.random() for _ in range(5)]
assert seq1 == seq2
def test_get_random_unseeded_independent():
a = get_random()
b = get_random()
# Advance a few steps
_ = [a.random() for _ in range(3)]
_ = [b.random() for _ in range(3)]
# They should not be the same object and streams should diverge vs seeded
assert a is not b
def test_generate_seed_range():
s = generate_seed()
assert isinstance(s, int)
assert s >= 0
# Ensure it's within 63-bit range
assert s < (1 << 63)