A slugify function with a bug. Fix the bug - not the test. A model passes this trial only when every test goes green — retries are included in the price, and the clock runs until done.
| Model | Verdict | Tries | Time | Cost to done | Tokens |
|---|---|---|---|---|---|
| gpt-5-mini | GREEN | x1 | 6s | $0.0009 | 382 |
| claude-haiku-4-5 | GREEN | x1 | 6s | $0.0021 | 647 |
| gpt-5.4 | GREEN | x1 | 5s | $0.0021 | 326 |
| claude-sonnet-4-6 | GREEN | x1 | 5s | $0.0023 | 372 |
| gpt-5.1 | GREEN | x1 | 5s | $0.0023 | 342 |
| gpt-5.2 | GREEN | x1 | 6s | $0.0023 | 338 |
| claude-sonnet-5 | GREEN | x1 | 7s | $0.0029 | 503 |
| gpt-5 | GREEN | x1 | 5s | $0.0030 | 351 |
| claude-opus-4-8 | GREEN | x1 | 6s | $0.0033 | 492 |
| gpt-5.5 | GREEN | x1 | 5s | $0.0035 | 304 |
| gpt-4.1 | GREEN | x1 | 6s | $0.0042 | 429 |
| claude-fable-5 | REFUSED | x6 | 30s | $0.0088 | 2784 |
Green row = cheapest to done · blue time = fastest to done. REFUSED = the model declined the task (a failure mode token prices never show). claude-fable-5's line is high-variance: follow-up probes saw it stochastically refuse benign coding prompts it had previously attempted. One trial per model per round; replies capped at 2,048 output tokens uniformly. Costs metered per session by cerver.
The file `solution.py` below has a bug: `test_unicode_dash` fails.
Fix the BUG (do not change test semantics). Return the COMPLETE fixed
`solution.py` in one ```python fenced block, nothing else.
```python
import re
import unicodedata
def slugify(text):
text = unicodedata.normalize("NFKD", text)
text = text.encode("ascii", "ignore").decode("ascii")
text = text.lower()
text = re.sub(r"[^a-z0-9]+", "_", text) # BUG lurks around separators
return text.strip("_")
```
Tests it must pass:
```python
def test_unicode_dash():
assert slugify("héllo — wörld") == "hello-world"
def test_spaces():
assert slugify("A B") == "a-b"
def test_empty():
assert slugify("") == ""
def test_idempotent():
assert slugify(slugify("Foo Bar")) == slugify("Foo Bar")
```
from solution import slugify
def test_unicode_dash():
assert slugify("héllo — wörld") == "hello-world"
def test_spaces():
assert slugify("A B") == "a-b"
def test_empty():
assert slugify("") == ""
def test_idempotent():
assert slugify(slugify("Foo Bar")) == slugify("Foo Bar")