| """ |
| tests/test_tokenizer.py |
| |
| Automated tests for BrainTokenizer -- this is what audit Problem #4 (zero |
| automated tests anywhere in Brain Trail) is fixed by. Every property that |
| used to be "eyeballed via a printed __main__ block" now runs under pytest |
| and fails loudly (not silently) if broken. |
| """ |
|
|
| from pathlib import Path |
|
|
| import pytest |
|
|
| from brain.tokenizer.tokenizer import BrainTokenizer |
| from brain.tokenizer.special_tokens import PAD, UNK, BOS, EOS |
|
|
| CORPUS_PATH = str(Path(__file__).resolve().parents[1] / "data" / "sample_corpus.txt") |
|
|
|
|
| @pytest.fixture(scope="module") |
| def tokenizer(): |
| return BrainTokenizer.train(CORPUS_PATH, vocab_size=1024, min_frequency=1) |
|
|
|
|
| def test_special_tokens_present(tokenizer): |
| for tok, tok_id in [(PAD, tokenizer.pad_id), (UNK, tokenizer.unk_id), |
| (BOS, tokenizer.bos_id), (EOS, tokenizer.eos_id)]: |
| assert tok_id is not None |
| assert tokenizer.id_to_token(tok_id) == tok |
|
|
|
|
| def test_vocab_size_positive(tokenizer): |
| assert tokenizer.vocab_size > len([PAD, UNK, BOS, EOS]) |
|
|
|
|
| @pytest.mark.parametrize("text", [ |
| "Hello Brain.", |
| "The quick brown fox jumps over the lazy dog.", |
| "def forward(self, x): return self.attn(x) + x", |
| "SELECT * FROM users WHERE id = 1;", |
| "Numbers: 100%, $50.25, user@example.com", |
| "", |
| "a", |
| ]) |
| def test_roundtrip_lossless(tokenizer, text): |
| ids = tokenizer.encode(text, add_special_tokens=False) |
| decoded = tokenizer.decode(ids, skip_special_tokens=True) |
| assert decoded == text |
|
|
|
|
| def test_add_special_tokens_wraps_with_bos_eos(tokenizer): |
| ids = tokenizer.encode("Hello Brain.", add_special_tokens=True) |
| assert ids[0] == tokenizer.bos_id |
| assert ids[-1] == tokenizer.eos_id |
|
|
|
|
| def test_batch_encode_padding_shapes(tokenizer): |
| batch = tokenizer.encode_batch(["short", "a much longer piece of text here"]) |
| lengths = {len(row) for row in batch["input_ids"]} |
| assert len(lengths) == 1, "all rows in a padded batch must be equal length" |
| assert len(batch["input_ids"]) == len(batch["attention_mask"]) == 2 |
|
|
|
|
| def test_batch_encode_attention_mask_marks_padding(tokenizer): |
| batch = tokenizer.encode_batch(["a", "a much longer sentence than the first one"]) |
| short_mask = batch["attention_mask"][0] |
| assert 0 in short_mask, "shorter sequence should have padding positions masked as 0" |
|
|
|
|
| def test_save_and_load_roundtrip(tokenizer, tmp_path): |
| save_path = tmp_path / "tok.json" |
| tokenizer.save(save_path) |
| reloaded = BrainTokenizer.from_file(save_path) |
| assert reloaded.vocab_size == tokenizer.vocab_size |
| text = "Round trip through disk." |
| assert reloaded.decode(reloaded.encode(text, add_special_tokens=False)) == text |
|
|
|
|
| def test_unicode_handling(tokenizer): |
| text = "Brægn — café — 日本語" |
| ids = tokenizer.encode(text, add_special_tokens=False) |
| assert tokenizer.decode(ids) == text |
|
|
|
|
| def test_token_stats_reasonable(tokenizer): |
| stats = tokenizer.token_stats("The quick brown fox jumps over the lazy dog.") |
| assert stats["n_tokens"] > 0 |
| assert stats["fertility"] > 0 |
|
|
