source/tests/fuzz_tools.py

"""Fuzz every tool of every task with hostile arguments; no call may raise, and every reward must be in [0, 1].

Usage: .venv/bin/python tests/fuzz_tools.py [--seeds 4] [--rounds 60]
"""

import argparse
import math
import random
import sys
import time
import traceback
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from diligence.environment import TASK_IDS, DiligenceEnvironment  # noqa: E402
from diligence.models import ToolAction  # noqa: E402

STRINGS = ["", " ", "\n", "None", "null", "-1", "0", "1e309", "nan", "../../etc/passwd", "/etc/passwd", "./", ".",
           "x" * 20000, "\x00", "é漢字🙂", "'; DROP TABLE invoices; --", "{{}}", "%s%s%n", "\\", "e1", "E1",
           "2026-10-05", "2026-02-30", "25:99", "09:00", "9:00", "09:00:00", "-09:00", "README.md", "DEPLOYMENT.md",
           "Dana Whitfield", "CWE-89", "cwe-89 sql injection", "SELECT 1", "print(1)", "import os; os._exit(0)"]
INTS = [0, 1, -1, 2, 7, 13, 99, 10 ** 18, -(10 ** 18), 2 ** 63]
FLOATS = [0.0, -0.0, 1.5, float("inf"), float("-inf"), float("nan"), 1e308]


def value(rng, depth=0):
    kind = rng.random()
    if kind < 0.35:
        return rng.choice(STRINGS)
    if kind < 0.5:
        return rng.choice(INTS)
    if kind < 0.6:
        return rng.choice(FLOATS)
    if kind < 0.65:
        return rng.choice([True, False, None])
    if depth > 2:
        return rng.choice(STRINGS)
    if kind < 0.82:
        return [value(rng, depth + 1) for _ in range(rng.randint(0, 4))]
    keys = STRINGS[:8] + ["answer", "value", "file", "line", "cwe", "total_usd", "top_customer", "date", "start"]
    return {str(rng.choice(keys)): value(rng, depth + 1) for _ in range(rng.randint(0, 4))}


def args_for(rng, tool):
    """Mostly well-typed arguments (so the tool body runs), sometimes extra, missing or mistyped ones."""
    out = {}
    for name, typ in tool.args.items():
        if rng.random() < 0.08:
            continue
        v = value(rng)
        if rng.random() < 0.8:
            for _ in range(50):
                if isinstance(v, typ) and not (typ in (int, float) and isinstance(v, bool)):
                    break
                v = value(rng)
        out[name] = v
    if rng.random() < 0.05:
        out[rng.choice(STRINGS[:5])] = value(rng)
    return out


def check(obs, where):
    assert isinstance(obs.output, str), where
    assert isinstance(obs.done, bool), where
    r = obs.reward
    assert r is None or (isinstance(r, (int, float)) and math.isfinite(r) and 0 <= r <= 1), (where, r)
    assert len(obs.output) <= 6100, (where, len(obs.output))


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--seeds", type=int, default=4)
    ap.add_argument("--rounds", type=int, default=60)
    args = ap.parse_args()
    rng = random.Random(12345)
    calls = failures = 0
    slowest = (0.0, "")
    for task_id in TASK_IDS:
        for seed in range(args.seeds):
            env = DiligenceEnvironment()
            for _ in range(args.rounds):
                if env._done:
                    check(env.reset(task_id=task_id, seed=seed, canonical_names=True), task_id)
                tool = rng.choice(list(env._tools.values()))
                if tool.name == "python" and rng.random() < 0.7:
                    continue  # python is slow; it gets its own adversarial tests
                action = {"tool": tool.name, "args": args_for(rng, tool)}
                if rng.random() < 0.03:
                    action["tool"] = rng.choice(STRINGS[:6]) or "x"
                where = f"{task_id} seed {seed} {str(action)[:300]}"
                t0 = time.monotonic()
                try:
                    check(env.step(ToolAction(**action)), where)
                except Exception:  # noqa: BLE001
                    failures += 1
                    print("FAIL", where)
                    traceback.print_exc(limit=3)
                took = time.monotonic() - t0
                slowest = max(slowest, (took, where[:160]))
                calls += 1
            # stepping after the episode is over must be harmless too
            env._done = True
            check(env.step(ToolAction(tool="submit", args={})), task_id)
        print(f"{task_id}: done ({calls} calls so far, {failures} failures)", flush=True)
    print(f"{calls} calls, {failures} failures; slowest {slowest[0]:.1f}s: {slowest[1]}")
    sys.exit(1 if failures else 0)


if __name__ == "__main__":
    main()