| from __future__ import annotations |
|
|
| import json |
| import math |
| import subprocess |
| import sys |
| from pathlib import Path |
|
|
| import pytest |
|
|
| pytest.importorskip("tokenizers") |
|
|
| from tokenizers import Tokenizer, models, pre_tokenizers |
|
|
| ROOT = Path(__file__).resolve().parents[1] |
|
|
|
|
| def build_tokenizer(path: Path) -> None: |
| vocab = { |
| "<unk>": 0, |
| "the": 1, |
| "quick": 2, |
| "brown": 3, |
| "fox": 4, |
| "jumps": 5, |
| "over": 6, |
| "lazy": 7, |
| "dog": 8, |
| "second": 9, |
| "line": 10, |
| "here": 11, |
| "third": 12, |
| "another": 13, |
| } |
| tokenizer = Tokenizer(models.WordLevel(vocab=vocab, unk_token="<unk>")) |
| tokenizer.pre_tokenizer = pre_tokenizers.Whitespace() |
| tokenizer.save(str(path / "tokenizer.json")) |
|
|
|
|
| def write_fixture(tmp_path: Path, *, tokens: int, chunks: int, ppl: float) -> tuple[Path, Path]: |
| corpus = tmp_path / "corpus.txt" |
| corpus.write_text( |
| "the quick brown fox jumps over the lazy dog\n" |
| "second line here\n" |
| "third another line here\n" * 4, |
| encoding="utf-8", |
| ) |
| tokenizer_dir = tmp_path / "tok" |
| tokenizer_dir.mkdir() |
| build_tokenizer(tokenizer_dir) |
| payload = { |
| "corpus": str(corpus), |
| "config": { |
| "corpus": str(corpus), |
| "max_sequences": chunks, |
| "max_tokens": 4, |
| "min_tokens": 1, |
| }, |
| "chunks": chunks, |
| "tokens": tokens, |
| "bf16_ppl": ppl, |
| "candidate_ppl": ppl * 1.1, |
| } |
| ppl_json = tmp_path / "ppl_en.json" |
| ppl_json.write_text(json.dumps(payload), encoding="utf-8") |
| return ppl_json, tokenizer_dir |
|
|
|
|
| def run(*args: str) -> subprocess.CompletedProcess[str]: |
| return subprocess.run( |
| [sys.executable, str(ROOT / "scripts" / "compute_bpc.py"), *args], |
| cwd=ROOT, |
| text=True, |
| capture_output=True, |
| check=False, |
| ) |
|
|
|
|
| def test_bpc_is_log2_ppl_times_fertility(tmp_path: Path) -> None: |
| ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=9, chunks=3, ppl=8.0) |
| out = tmp_path / "report.json" |
| result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--json", str(out)) |
| assert result.returncode == 0, result.stdout + result.stderr |
| report = json.loads(out.read_text(encoding="utf-8"))[0] |
| assert report["chunks"] == 3 |
| |
| assert report["tokens"] == report["chunks"] * 3 |
| assert report["chars"] > 0 |
| expected = math.log2(8.0) * report["tokens"] / report["chars"] |
| assert report["bpc_bf16"] == pytest.approx(expected) |
| assert report["bpc_candidate"] == pytest.approx(math.log2(8.8) * report["tokens"] / report["chars"]) |
| assert report["reproduced"]["chunks_match"] is True |
| assert report["reproduced"]["tokens_match"] is True |
|
|
|
|
| def test_strict_mode_flags_token_drift(tmp_path: Path) -> None: |
| ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=99, chunks=3, ppl=8.0) |
| result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--strict") |
| assert result.returncode == 1 |
| assert "tokens_match" in result.stdout |
|
|
|
|
| def test_accepts_corpus_override(tmp_path: Path) -> None: |
| ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=9, chunks=3, ppl=8.0) |
| payload = json.loads(ppl_json.read_text(encoding="utf-8")) |
| payload["corpus"] = str(tmp_path / "missing.txt") |
| payload["config"]["corpus"] = str(tmp_path / "missing.txt") |
| ppl_json.write_text(json.dumps(payload), encoding="utf-8") |
| override = tmp_path / "corpus.txt" |
| result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--corpus", str(override)) |
| assert result.returncode == 0, result.stdout + result.stderr |
|
|
