Files
rzen c202bada6a Phase 2: token dataset + corpus encoder (code only, not yet run)
- src/dataset.py: memmap uint16 token loader + random-crop batch sampler
  (x, y shifted-by-one, reproducible via generator)
- scripts/encode_corpus.py: stream stories -> encode -> uint16 .bin, one EOT
  token appended per story, flat memory. encode_file() factored out for testing.
- tests/test_dataset.py: batch shapes/shift/bounds/reproducibility +
  encoder round-trip/separators/uint16 on synthetic data (5 tests)
2026-07-12 10:38:20 -04:00

100 lines
3.2 KiB
Python

"""Dataset + corpus-encoding tests on synthetic data (no real corpus needed).
Run directly: `.venv/bin/python tests/test_dataset.py`
"""
import sys
import tempfile
from pathlib import Path
import numpy as np
import torch
ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(ROOT / "src"))
sys.path.insert(0, str(ROOT / "scripts"))
from dataset import TOKEN_DTYPE, get_batch, load_tokens # noqa: E402
from tokenizer import BPETokenizer # noqa: E402
from encode_corpus import encode_file # noqa: E402
EOT = "<|endoftext|>"
def test_get_batch_shapes_and_shift():
# Tokens 0..999 in order, so the shift property is easy to verify.
data = np.arange(1000, dtype=TOKEN_DTYPE)
gen = torch.Generator().manual_seed(0)
x, y = get_batch(data, batch_size=8, context_length=16, device="cpu", generator=gen)
assert x.shape == (8, 16) and y.shape == (8, 16)
assert x.dtype == torch.long
# y is x shifted by one; with sequential data each y == x + 1.
assert torch.equal(y, x + 1)
def test_get_batch_is_reproducible():
data = np.arange(1000, dtype=TOKEN_DTYPE)
a = get_batch(data, 4, 8, "cpu", torch.Generator().manual_seed(42))
b = get_batch(data, 4, 8, "cpu", torch.Generator().manual_seed(42))
assert torch.equal(a[0], b[0]) and torch.equal(a[1], b[1])
def test_get_batch_in_bounds():
data = np.arange(50, dtype=TOKEN_DTYPE)
x, y = get_batch(data, 32, 8, "cpu", torch.Generator().manual_seed(1))
assert int(x.max()) < 50 and int(y.max()) < 50
def _tiny_tokenizer() -> BPETokenizer:
corpus = ("The cat sat. Tom ran fast. Lily played.\n" + EOT + "\n") * 40
return BPETokenizer.train(corpus, vocab_size=350, special_tokens=[EOT])
def test_encode_file_roundtrip_and_separators():
tok = _tiny_tokenizer()
eot_id = tok.special_tokens[EOT]
with tempfile.TemporaryDirectory() as d:
src = Path(d) / "mini.txt"
dst = Path(d) / "mini.bin"
# Two stories, separator on its own line, with stray blank lines.
src.write_text(
"The cat sat.\nTom ran fast.\n" + EOT + "\n\n"
"Lily played.\n" + EOT + "\n"
)
n_stories, n_tokens = encode_file(tok, src, dst, progress=False)
assert n_stories == 2
ids = load_tokens(dst).tolist()
assert len(ids) == n_tokens
# Exactly one EOT per story, and each story ends with one.
assert ids.count(eot_id) == 2
assert ids[-1] == eot_id
# Content between separators decodes back to the original stories.
first = ids[: ids.index(eot_id)]
assert tok.decode(first) == "The cat sat.\nTom ran fast."
def test_encoded_ids_fit_uint16():
tok = _tiny_tokenizer()
with tempfile.TemporaryDirectory() as d:
src = Path(d) / "m.txt"
dst = Path(d) / "m.bin"
src.write_text("The cat sat.\n" + EOT + "\n")
encode_file(tok, src, dst, progress=False)
arr = load_tokens(dst)
assert arr.dtype == TOKEN_DTYPE # stored as uint16
assert int(arr.max()) < 65536
def main() -> None:
tests = [v for k, v in sorted(globals().items()) if k.startswith("test_")]
for t in tests:
t()
print(f"ok {t.__name__}")
print(f"\n{len(tests)} passed")
if __name__ == "__main__":
main()