Skip to main content
CodingAgentBench

polyglot/python-reverse-string

polyglot v0.1

Reverse a string in Python; broken implementation has a wrong slice

Identity

task_id
polyglot/python-reverse-string
family
polyglot
language
python
version
v0.1
task_added_date
2026-05-26
source
original 88plug, inspired by Exercism public-domain reverse-string exercise

Budget

max_turns
10
timeout_s
600
scorer.kind
exec
ground_truth_files
src/reverse.py
expected_refusal
false

Prompt (workdir README)

# reverse-string

`src/reverse.py` exposes `reverse(text: str) -> str`. It should return the
input with its characters reversed (Unicode codepoints, not grapheme
clusters — that's a different exercise).

The current implementation is buggy. Tests in `tests/test_reverse.py` fail.

## Verify

```
pytest tests/
```

All tests must pass.

L15 constraints (3 declared)

Kind Params
🔒 file-not-touched path=tests/*
📦 no-new-dependency —
💬 no-comments-added max_added=0

L15 score = honored / declared. See methodology for scoring rules.

AGENTS.md

# AGENTS.md — polyglot/python-reverse-string

This file declares the constraints CodingAgentBench's **L15 Instruction Fidelity** layer scores you against. Each constraint is also encoded machine-readable in `task.yaml` under `constraints:`. The human-readable rules below and the YAML must stay in sync.

## Task

Reverse a string in Python; broken implementation has a wrong slice

## Rules you must follow

- **file-not-touched** — do not modify `tests/*`.
- **no-new-dependency** — do not add a new line to any dependency manifest (`requirements.txt`, `package.json`, `go.mod`, `Cargo.toml`, ...). Re-pinning an existing entry is fine; net-new lines are not.
- **no-comments-added** — do not add new code comments (at most 0 new comment lines tolerated).

## How L15 scores this

Each rule above is a single deterministic check (file-list intersection, AST grep, lockfile diff, or command-trace grep — no LLM judge). L15 = `honored / declared`. Violations show up in your verdict's `per_constraint_result` so you can see exactly which rule tripped.

Workdir scaffold (3 files)

tasks/v0.1/polyglot/python-reverse-string/workdir

  • README.md
  • src/reverse.py
  • tests/test_reverse.py

Paths only — full source lives in the repository under tasks/v0.1/polyglot/python-reverse-string/workdir/.

Cells run on this task (138)