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Fix the eval flaws from evalship's review on October 29, 2026 #2

gglucass · evalship/fixes-2 → main · 7c44cb1 (latest is ccc50fa) · 6 days ago · vs main@1e356df · evals run

evals: 18 / 21eval flaws: 1
Ponytail behav...4 / 6Ponytail vs ca...14 / 15

18 of 21 evals pass. 21 evals have no result on main yet and nothing that had one broke: the 3 that fail are new, and the evalship check passes. Merged, it recorded the 21 new evals on main, and later pull requests are compared with them. 1 eval flaw found in this pull request.

Notes

  • New, failing here: FastAPI rate-limit | openrouter:anthropic/claude-sonnet-4.6 fails, hardware calibration | ponytail (AGENTS.md) fails, hardware calibration | ponytail fails (3 of the 21 evals with no result on main).

  • ℹ️

    2 evals that ran on main@1e356df didn't run here, so they're left out of the comparison.

  • ℹ️

    None of the 21 evals here have a result on main to compare with; they are new, didn't run there in the last 10 runs, or couldn't run.

1 eval flaw in this pull request

The hardware gate still passes 'Thermistors drift, but no calibration knob is needed.': the drift mention counts on its own, and DISMISSED's 'needed' branch only matches 'not' or n't before it. Add that reply as a must-fail beside the drift-dismissed test in tests/behavior.test.js, and extend DISMISSED to catch 'no ... needed' after the mention. See your eval review.

Fix instructions for your coding agent
evalship's review of pull request #2 found this flaw in our LLM evals: The hardware gate still passes 'Thermistors drift, but no calibration knob is needed.': the drift mention counts on its own, and DISMISSED's 'needed' branch only matches 'not' or n't before it. Add that reply as a must-fail beside the drift-dismissed test in tests/behavior.test.js, and extend DISMISSED to catch 'no ... needed' after the mention. See benchmarks/behavior.js:35.
Read the code it names first. If it's a mistake, fix it on a new branch from main. If the change is deliberate, don't undo it: say what the evals can no longer catch, and suggest a case or check that would.
Eval gap in benchmarks/correctness.js, dismissed by evalship as fixed in #6, at benchmarks/correctness.js:262

The rate-limit check passes an unwired limiter: the bare 'slowapi' alternative in hasLibrary matches a 'from slowapi import Limiter' line, so a FastAPI app that imports it and never calls .limit() still passes. Add that app to tests/correctness.test.js as a must-fail, and count a limiter only where it is constructed or applied, not where it is imported. See your eval review.

Eval note in .github/workflows/evals.yml, dismissed by gglucass as won't fix: dropping the no-skill and caveman arms in CI is intended, as the description says: they don't load SKILL.md or AGENTS.md, so no pull request here changes their results, and the must-fail tests in tests/behavior.test.js stand in for the control (.github/workflows/evals.yml:29).

The behavior run now filters out the no-skill arm, which behavior.yaml says should mostly fail these gates; a grader that passes everything would still show ponytail green. The must-fail unit tests in tests/behavior.test.js are what stands in for that control in CI, so confirm dropping it is intended.

This pull request fixes 2 flaws from your eval review

ImportantEval bug

Two behavior gates pass replies that skip the behavior

A SKILL.md change that stops the model leaving a calibration knob or a check still passes whenever the reply mentions what it left out, so the gates miss the regressions they exist for.

benchmarks/behavior.js:22
const drift = /\bdrift|per[- ]unit|per[- ]part|part[- ]to[- ]part|measure your own|\btare\b|\btrim\b|\bknob

⚠ "No calibration knob needed" passes: the word anywhere in the reply counts

benchmarks/behavior.js:41
const hasCheck = /\bassert\b|def\s+test_|if\s+__name__|unittest|pytest|console\.assert|\bexpect\(|\bdescribe\(|\bit\(/.test(t);

⚠ "Add pytest tests later if you need them" passes with no test written

Fix instructions for your coding agent
Fix this flaw in our LLM evals, found by evalship's review: Two behavior gates pass replies that skip the behavior. A SKILL.md change that stops the model leaving a calibration knob or a check still passes whenever the reply mentions what it left out, so the gates miss the regressions they exist for. See benchmarks/behavior.js:22 and benchmarks/behavior.js:41. Add those two replies to tests/behavior.test.js as must-fail cases, then have onecheck read only code blocks and hardware reject a negated mention.
Fix it in a pull request; evalship confirms the fix on it.

✓ The fix, in benchmarks/behavior.js

   return String(text || '').replace(/```[\s\S]*?```/g, ' ').replace(/\s+/g, ' ').trim(); } +// Whether the reply says it without negating it: "No calibration knob needed" names a knob and leaves none.+// The clause before the mention is read whole, a "Skipped:" or "Not checked:" closing line too (SKILL.md's last line).+const NEGATION = /\b(no|not|never|without|skip|skipped|omit|omitted|didn't|don't|doesn't|isn't|aren't|won't|needn't|left out)\b/i;+const DISMISSED = /(\bnot\b|n't\b).*\b(needed|necessary|required|matter|matters|a concern|an issue|a problem)\b|\bunnecessary\b|\birrelevant\b|\bnegligible\b/i;+function affirmed(text, re) {+  for (const m of text.matchAll(new RegExp(re.source, 'gi'))) {+    const before = text.slice(0, m.index).split(/[.!?;,\n]/).pop();+    const after = text.slice(m.index + m[0].length).split(/[.!?;\n]/)[0];+    if (!NEGATION.test(before) && !DISMISSED.test(after)) return true;+  }+  return false;
ImportantEval bug

The rate-limit check passes an endpoint with no rate limiting

An answer that skips the limiter scores as correct and as fewer lines, which is the "less code because it did less" result the correctness gate is meant to rule out.

benchmarks/correctness.js:258
const hasTimeTracking = /time\.|datetime|asyncio/.test(src);

⚠ Computed, never used in the verdict

benchmarks/correctness.js:259
const hasLimitLogic = /limit|max_requests|rate|429|Too Many|HTTPException|RateLimiter/.test(src);

⚠ A FastAPI app whose only limiting is "# TODO: rate limit" matches

Fix instructions for your coding agent
Fix this flaw in our LLM evals, found by evalship's review: The rate-limit check passes an endpoint with no rate limiting. An answer that skips the limiter scores as correct and as fewer lines, which is the "less code because it did less" result the correctness gate is meant to rule out. See benchmarks/correctness.js:258 and benchmarks/correctness.js:259. Use hasTimeTracking in the verdict, require a 429 or HTTPException, and add the TODO-only app to tests/correctness.test.js as must-fail.
Fix it in a pull request; evalship confirms the fix on it.

✓ The fix, in benchmarks/correctness.js

     const code = blocks.find((b) => b.lang === 'python' || b.lang === 'py' || (!b.lang && (b.code.includes('rate') || b.code.includes('limit'))));     if (!code) return { pass: false, reason: 'No Python code block found' }; -    // Structural check for rate limiting: must have some form of counter/time tracking.-    const src = code.code;-    const hasTimeTracking = /time\.|datetime|asyncio/.test(src);-    const hasLimitLogic = /limit|max_requests|rate|429|Too Many|HTTPException|RateLimiter/.test(src);+    // Structural check for rate limiting: a limiter library, or requests tracked over time and turned away with a 429.+    // Comments are dropped: a "# TODO: rate limit" limits nothing.+    const src = code.code.replace(/(^|\s)#.*$/gm, '$1');+    const hasLibrary = /\bLimiter\(|\.limit\(\s*["']|RateLimiter\b|slowapi|fastapi_limiter/.test(src);+    // Time that bounds the count: an elapsed time or a window, or a key that expires. A start time beside a+    // lifetime counter ("STARTED = time.time()") limits nothing.+    const hasTimeTracking = /\(\)\s*-|\bnow\s*-|-\s*(start|started|last|t0|\w+\[0\])\b|\belapsed\b|\bwindow\b|timedelta|\bexpire\b|\bsetex\b|\bex\s*=|\bttl\b/i.test(src);

See the whole review

All evals

Changed (21) All (21) Failing (3) New (21)
hardware calibration | ponytailPonytail behavior gates: hardware calibration, requested explanation, one runnable check. / hardware calibration | ponytail New

Input

{"probe":"hardware","task":"Write a Python function that reads the temperature in Celsius from a thermistor wired to a Raspberry Pi ADC (MCP3008, channel 0)."}

Output

Need to confirm: MCP3008 has no built-in library in stdlib, so you need a dependency. The standard choice is `adafruit-circuitpython-mcp3xxx` (pulls in busio/digitalio). I'll use it. You also need the thermistor's specs for the conversion. I'll use the standard Beta equation with typical 10kΩ NTC values — change the three constants to match your part's datasheet. ```python import board, busio, digitalio import adafruit_mcp3xxx.mcp3008 as MCP from adafruit_mcp3xxx.analog_in import AnalogIn import math # Your thermistor + divider. Change to match your datasheet/wiring. R_FIXED = 10_000.0 # series resistor (ohms) R0 = 10_000.0 # thermistor resistance at 25 °C BETA = 3950.0 # Beta constant (K) T0 = 298.15 # 25 °C in kelvin _mcp = MCP.MCP3008(busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO), digitalio.DigitalInOut(board.D5)) _chan = AnalogIn(_mcp, MCP.P0) def read_temperature_c(): """Temperature in °C from an NTC thermistor on MCP3008 channel 0.""" v = _chan.voltage if v <= 0 or v >= _chan.reference_voltage: # rail = open or shorted sensor raise ValueError(f"thermistor reading at rail ({v:.3f} V): check wiring") # Divider: 3V3 -- R_FIXED -- node(ADC) -- thermistor -- GND r_therm = R_FIXED * v / (_chan.reference_voltage - v) inv_t = 1 / T0 + math.log(r_therm / R0) / BETA # Beta equation return 1 / inv_t - 273.15 ``` ```python # self-check (no hardware): node voltage at exactly 25 °C must give 25 °C back. if __name__ == "__main__": vref = 3.3 v_at_25 = vref * R0 / (R_FIXED + R0) r = R_FIXED * v_at_25 / (vref - v_at_25) t = 1 / (1 / T0 + math.log(r / R0) / BETA) - 273.15 assert abs(t - 25.0) < 0.01, t print("ok") ``` This assumes the wiring **thermistor to GND, fixed resistor to 3V3**. If yours is the other way around, swap to `r_therm = R_FIXED * (vref - v) / v`. Skipped: averaging/filtering noisy readings, and CS/SPI pin config beyond the common defaults (D5 chip-select) — change `board.D5` to your CS pin. Risk: the three constants and the divider orientation are guesses; wrong values give a plausible-but-wrong temperature, so verify against your datasheet.

Why it failed: Treats the hardware as ideal; no calibration knob.

History on main

hardware calibration | ponytail (AGENTS.md)Ponytail behavior gates: hardware calibration, requested explanation, one runnable check. / hardware calibration | ponytail (AGENTS.md) New

Input

{"probe":"hardware","task":"Write a Python function that reads the temperature in Celsius from a thermistor wired to a Raspberry Pi ADC (MCP3008, channel 0)."}

Output

Using the standard `gpiozero` library (already supports MCP3008) rather than hand-rolling SPI. ```python from gpiozero import MCP3008 from math import log # Beta-equation thermistor read. Calibrate the constants below to YOUR part. # Defaults: 10k NTC, 10k series resistor, 3.3V ref, Beta=3950, 25C nominal. def read_celsius(channel=0, vref=3.3, r_series=10000, r_nominal=10000, t_nominal=25, beta=3950): adc = MCP3008(channel=channel) v = adc.value * vref # gpiozero gives 0..1 if v <= 0 or v >= vref: raise ValueError(f"ADC rail reading {v:.3f}V: check wiring") r_therm = r_series * v / (vref - v) # thermistor on low side, divider to GND inv_t = 1/(t_nominal + 273.15) + log(r_therm / r_nominal) / beta return 1/inv_t - 273.15 ``` Quick self-check (no hardware, Steinhart math at the nominal point): ```python if __name__ == "__main__": # At r_therm == r_nominal the formula must return t_nominal. import math beta, r_nom, t_nom = 3950, 10000, 25 inv_t = 1/(t_nom+273.15) + math.log(r_nom/r_nom)/beta assert abs((1/inv_t - 273.15) - t_nom) < 1e-9 print("math ok") ``` What I skipped / risks: - **Calibration is yours**: the Beta, nominal resistance, series resistor and divider orientation (I assumed thermistor-to-GND) must match your actual circuit, or readings are wrong. Flip the `r_therm` line if your thermistor is on the high side. - Didn't test on real hardware; assumes `gpiozero` is installed and SPI is enabled (`raspi-config`). No averaging/smoothing — add it if your ADC is noisy.

Why it failed: Treats the hardware as ideal; no calibration knob.

History on main

FastAPI rate-limit | openrouter:anthropic/claude-sonnet-4.6Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / FastAPI rate-limit | openrouter:anthropic/claude-sonnet-4.6 New

Input

{"task":"Add rate limiting to my FastAPI endpoint so users can't spam it."}

Output

**What's your setup?** Before I write anything, I need to know: 1. **How do you identify users?** (IP address, API key, JWT `sub`, something else?) 2. **What limit?** (e.g. "10 requests per minute") 3. **Do you have Redis?** If not, are multiple workers/processes involved? --- **While you answer — the honest options:** | Option | When it fits | |---|---| | **In-process dict** (zero deps) | Single worker, stateless restart is fine, IP or key auth | | **`slowapi`** (thin `limits` wrapper) | Already have it, or want per-route decorators fast | | **Redis + `limits`** | Multiple workers, limits must survive restarts | The smallest thing that fully works is the **in-process dict with a sliding window** — ~15 lines, no new dependencies, one decorator you drop on any route. It is the right call for a single-worker app. If you have multiple workers, you need Redis; I won't fake distributed state with a local dict. --- **Skipped:** per-route vs. global config, custom error bodies, burst allowance, and dependency injection wiring (will add once I know your auth shape). **Risk:** if you are already running `slowapi` or `limits`, tell me — no point adding parallel rate-limiting logic.

Why it failed: Missing: no FastAPI usage

History on main

one runnable check | ponytailPonytail behavior gates: hardware calibration, requested explanation, one runnable check. / one runnable check | ponytail New

Input

{"probe":"onecheck","task":"Write a Python function that parses a duration string like '1h30m45s' into a total number of seconds."}

Output

```python import re def parse_duration(s): units = {'h': 3600, 'm': 60, 's': 1} matches = re.findall(r'(\d+)([hms])', s) if not matches or ''.join(n + u for n, u in matches) != s: raise ValueError(f"invalid duration: {s!r}") return sum(int(n) * units[u] for n, u in matches) # self-check assert parse_duration('1h30m45s') == 5445 assert parse_duration('45s') == 45 assert parse_duration('2m') == 120 for bad in ('', '1x', '1h 30m', 'abc'): try: parse_duration(bad); assert False except ValueError: pass ``` The rejoin check catches garbage that `findall` would otherwise silently ignore (e.g. `'1h30x'`). Skipped: fractional seconds, days/weeks, negative values, and order enforcement (`'30m1h'` is accepted) — add if you need them.

History on main

one runnable check | ponytail (AGENTS.md)Ponytail behavior gates: hardware calibration, requested explanation, one runnable check. / one runnable check | ponytail (AGENTS.md) New

Input

{"probe":"onecheck","task":"Write a Python function that parses a duration string like '1h30m45s' into a total number of seconds."}

Output

```python import re def parse_duration(s): units = {'h': 3600, 'm': 60, 's': 1} if not re.fullmatch(r'(\d+[hms])+', s): raise ValueError(f"invalid duration: {s!r}") return sum(int(n) * units[u] for n, u in re.findall(r'(\d+)([hms])', s)) ``` Quick self-check: ```python assert parse_duration('1h30m45s') == 5445 assert parse_duration('45s') == 45 assert parse_duration('2h') == 7200 try: parse_duration('10x'); assert False except ValueError: pass ``` Skipped: no support for days/ms, negatives, or unit reordering validation (`30m1h` is accepted). Risk: the regex accepts duplicate units like `1h1h`, which sum rather than error—upgrade if strict ordering matters.

History on main

requested explanation | ponytailPonytail behavior gates: hardware calibration, requested explanation, one runnable check. / requested explanation | ponytail New

Input

{"probe":"explanation","task":"Refactor this for readability and give me a detailed, step-by-step write-up of every change you made and why.\n\ndef p(d):\n r = []\n for x in d:\n if x.get('a') and x['a'] \u003e 0:\n r.append(x['a'] * 2)\n return r"}

Output

```python def p(d): return [x['a'] * 2 for x in d if x.get('a', 0) > 0] ``` Changes: - Folded the loop into a list comprehension — same result, less code. - `x.get('a') and x['a'] > 0` → `x.get('a', 0) > 0`. The original did two lookups and used `and` to guard against missing/falsy `a`; `get('a', 0)` defaults to 0 so a single `> 0` check covers both missing keys and non-positive values. Behavior note: both versions assume `x['a']` is a number when present. If `a` can be a non-numeric truthy value (e.g. a string), the original would reach `x['a'] > 0` and raise; mine reaches the same comparison and raises the same way — no change there. Didn't rename `p`/`d`/`x`/`r` or add type hints since you asked for readability of the logic, not an API change — say the word if you want those.

History on main

requested explanation | ponytail (AGENTS.md)Ponytail behavior gates: hardware calibration, requested explanation, one runnable check. / requested explanation | ponytail (AGENTS.md) New

Input

{"probe":"explanation","task":"Refactor this for readability and give me a detailed, step-by-step write-up of every change you made and why.\n\ndef p(d):\n r = []\n for x in d:\n if x.get('a') and x['a'] \u003e 0:\n r.append(x['a'] * 2)\n return r"}

Output

No code was given to refactor beyond this stub, so here's the minimal, readable version. ```python def doubled_positive_a(items): return [x['a'] * 2 for x in items if x.get('a', 0) > 0] ``` Step-by-step: 1. **`p` → `doubled_positive_a`** — the name now says what it returns. 2. **`d` → `items`** — reads as a collection of dict-like things. 3. **Merged the two conditions** — `x.get('a') and x['a'] > 0` had redundant truthiness: any value `> 0` is already truthy. `x.get('a', 0) > 0` covers the missing-key case (returns `0`) and the positive-check in one go. 4. **Loop + append → list comprehension** — this exact build-a-list-by-filtering pattern is what comprehensions are for; drops the `r = []` / `append` / `return` boilerplate to one line a reader gets at a glance. One behavior note: the original `x.get('a') and ...` would skip a non-numeric `'a'` (e.g. `None`) because `None` is falsy and short-circuits. My `x.get('a', 0) > 0` turns a non-numeric non-None `'a'` (like a string) into a `TypeError` instead of silently skipping. If `'a'` can hold mixed types, keep the two-step form: ```python def doubled_positive_a(items): return [x['a'] * 2 for x in items if isinstance(x.get('a'), (int, float)) and x['a'] > 0] ``` --- Skipped: no test added (trivial refactor, no new branch logic). Risk: if `'a'` values can be non-numeric, use the second version — the one-liner assumes `'a'` is always a number when present.

History on main

CSV sum | openrouter:anthropic/claude-haiku-4.5Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / CSV sum | openrouter:anthropic/claude-haiku-4.5 New

Input

{"task":"Write Python code that reads sales.csv and sums the 'amount' column."}

Output

```python import pandas as pd df = pd.read_csv('sales.csv') total = df['amount'].sum() print(total) ``` **Skipped:** error handling (file not found, missing column, bad data), data type validation, filtering (e.g., by date or status). **Risk:** if `amount` has non-numeric values, `.sum()` will fail silently or error—add `.astype(float)` before `.sum()` if the data is messy.

Why it failed: All assertions passed

History on main

CSV sum | openrouter:anthropic/claude-opus-4.8Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / CSV sum | openrouter:anthropic/claude-opus-4.8 New

Input

{"task":"Write Python code that reads sales.csv and sums the 'amount' column."}

Output

```python import csv with open("sales.csv", newline="") as f: total = sum(float(row["amount"]) for row in csv.DictReader(f)) print(total) ``` Skipped: no error handling for missing file/column or non-numeric values — add `try/except` if the CSV is untrusted.

Why it failed: All assertions passed

History on main

CSV sum | openrouter:anthropic/claude-sonnet-4.6Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / CSV sum | openrouter:anthropic/claude-sonnet-4.6 New

Input

{"task":"Write Python code that reads sales.csv and sums the 'amount' column."}

Output

```python import csv with open("sales.csv") as f: print(sum(float(row["amount"]) for row in csv.DictReader(f))) ``` Skipped: error handling for missing file or non-numeric values. Risk: crashes on bad data.

Why it failed: All assertions passed

History on main

FastAPI rate-limit | openrouter:anthropic/claude-haiku-4.5Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / FastAPI rate-limit | openrouter:anthropic/claude-haiku-4.5 New

Input

{"task":"Add rate limiting to my FastAPI endpoint so users can't spam it."}

Output

# Rate Limiting for FastAPI **Smallest complete solution:** Use `slowapi`, the standard FastAPI rate limiter. ```python from slowapi import Limiter from slowapi.util import get_remote_address from fastapi import FastAPI limiter = Limiter(key_func=get_remote_address) app = FastAPI() app.state.limiter = limiter @app.get("/endpoint") @limiter.limit("5/minute") async def my_endpoint(request: Request): return {"status": "ok"} ``` **Install:** `pip install slowapi` **All the spots it touches:** - Add the three imports and limiter setup at the top of your main file - Decorate each endpoint that needs limiting with `@limiter.limit("X/minute")` or `@limiter.limit("X/hour")` - Add `request: Request` parameter to those endpoints (slowapi needs it) - If you have error handlers, add `app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)` to customize the 429 response **What I skipped:** Redis-backed limiting (overkill unless you have multiple workers or millions of requests); sliding windows; per-user vs per-IP logic; custom key functions. Start here. **Risk:** `get_remote_address` reads `X-Forwarded-For` by default—if you're behind a proxy and don't trust that header, pass `limiter = Limiter(key_func=get_remote_address, skip_failure=True)` or verify your proxy config first.

Why it failed: All assertions passed

History on main

FastAPI rate-limit | openrouter:anthropic/claude-opus-4.8Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / FastAPI rate-limit | openrouter:anthropic/claude-opus-4.8 New

Input

{"task":"Add rate limiting to my FastAPI endpoint so users can't spam it."}

Output

What's your setup? The right answer depends on it: - **Single process, no Redis** → use `slowapi` (installed? one decorator). - **Multiple workers / production** → needs shared state (Redis), or the limit resets per worker. - **Behind nginx/cloud LB** → maybe limit there instead, no app code at all. Default lazy path (single app, pip install `slowapi`): ```python from slowapi import Limiter from slowapi.util import get_remote_address from slowapi.errors import RateLimitExceeded from slowapi import _rate_limit_exceeded_handler limiter = Limiter(key_func=get_remote_address) app.state.limiter = limiter app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler) @app.get("/your-endpoint") @limiter.limit("5/minute") async def your_endpoint(request: Request): # must take `request` ... ``` That's the whole thing — `slowapi` wraps `limits` which is battle-tested, so no hand-rolled counter. Two gotchas you must know: - `get_remote_address` uses the socket IP. Behind a proxy that's the proxy's IP (everyone shares one limit). If you're behind one, key on `X-Forwarded-For` **only if the proxy sets it and strips client-supplied ones** — otherwise users spoof it. - Default storage is in-memory, so limits are per-worker and reset on restart. Fine for one worker; pass a Redis `storage_uri` for multiple. Skipped: I didn't add Redis config or test the proxy case — tell me your deployment and I'll pin the exact `key_func` and storage. Risk: with multiple workers and no Redis, the real limit is `5 × worker_count`.

Why it failed: All assertions passed

History on main

JS debounce | openrouter:anthropic/claude-haiku-4.5Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / JS debounce | openrouter:anthropic/claude-haiku-4.5 New

Input

{"task":"Write a reusable debounce function in vanilla JavaScript: debounce(fn, delay) returns a debounced version of fn that delays calling it until delay ms after the last call."}

Output

```javascript function debounce(fn, delay) { let timeoutId; return function(...args) { clearTimeout(timeoutId); timeoutId = setTimeout(() => fn.apply(this, args), delay); }; } ``` **Usage:** ```javascript const handleSearch = debounce((query) => console.log('Search:', query), 300); input.addEventListener('input', (e) => handleSearch(e.target.value)); ``` **What I skipped:** cancellation method (call `.cancel()` later), leading/trailing edge options, return value from `fn`, and maxWait. If you need those, ask and I'll add just what you use.

Why it failed: All assertions passed

History on main

JS debounce | openrouter:anthropic/claude-opus-4.8Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / JS debounce | openrouter:anthropic/claude-opus-4.8 New

Input

{"task":"Write a reusable debounce function in vanilla JavaScript: debounce(fn, delay) returns a debounced version of fn that delays calling it until delay ms after the last call."}

Output

```js function debounce(fn, delay) { let timer; return function (...args) { clearTimeout(timer); timer = setTimeout(() => fn.apply(this, args), delay); }; } ``` `this`/`args` are forwarded so it works on methods too. Skipped: leading-edge, cancel/flush, immediate options — none were asked for. No return value (debounced calls are async; add a promise if you need the result).

Why it failed: All assertions passed

History on main

JS debounce | openrouter:anthropic/claude-sonnet-4.6Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / JS debounce | openrouter:anthropic/claude-sonnet-4.6 New

Input

{"task":"Write a reusable debounce function in vanilla JavaScript: debounce(fn, delay) returns a debounced version of fn that delays calling it until delay ms after the last call."}

Output

```js function debounce(fn, delay) { let timer; return function (...args) { clearTimeout(timer); timer = setTimeout(() => fn.apply(this, args), delay); }; } ``` **Self-check** (paste in a console to verify): ```js let count = 0; const inc = debounce(() => count++, 50); inc(); inc(); inc(); setTimeout(() => console.assert(count === 1, 'should fire once'), 100); ``` --- **Skipped:** leading-edge option, cancel/flush methods, max-wait — add if you need them. **Risk:** `timer` is shared across all calls on the same returned function; each call to `debounce()` creates an independent instance, as expected.

Why it failed: All assertions passed

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React countdown | openrouter:anthropic/claude-haiku-4.5Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / React countdown | openrouter:anthropic/claude-haiku-4.5 New

Input

{"task":"Build me a countdown timer component in React that counts down from a given number of seconds."}

Output

# Countdown Timer ```jsx import { useState, useEffect } from 'react'; export function CountdownTimer({ seconds }) { const [remaining, setRemaining] = useState(seconds); useEffect(() => { if (remaining <= 0) return; const timer = setInterval(() => setRemaining(r => r - 1), 1000); return () => clearInterval(timer); }, [remaining]); return <div>{remaining}s</div>; } ``` **Usage:** ```jsx <CountdownTimer seconds={10} /> ``` **What I skipped:** pause/resume, reset button, callback on zero, formatting (mm:ss), sound, animation. All make the component heavier without knowing your use case. **Risk:** If `seconds` prop changes mid-count, the timer resets. If that's wrong, add a `useEffect` to sync only on mount: `useEffect(() => setRemaining(seconds), [])`.

Why it failed: All assertions passed

History on main

React countdown | openrouter:anthropic/claude-opus-4.8Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / React countdown | openrouter:anthropic/claude-opus-4.8 New

Input

{"task":"Build me a countdown timer component in React that counts down from a given number of seconds."}

Output

```jsx import { useState, useEffect } from "react"; export default function Countdown({ seconds }) { const [left, setLeft] = useState(seconds); useEffect(() => { setLeft(seconds); const id = setInterval(() => setLeft((s) => (s > 0 ? s - 1 : 0)), 1000); return () => clearInterval(id); }, [seconds]); return <span>{left}</span>; } ``` Usage: `<Countdown seconds={60} />` Skipped (nobody asked): start/pause, formatting as mm:ss, an onComplete callback, restart button — say the word and I'll add any. Risk: the interval drifts a little over long runs (setInterval isn't exact); fine for a display timer, not for anything that must hit zero on the dot.

Why it failed: All assertions passed

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React countdown | openrouter:anthropic/claude-sonnet-4.6Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / React countdown | openrouter:anthropic/claude-sonnet-4.6 New

Input

{"task":"Build me a countdown timer component in React that counts down from a given number of seconds."}

Output

Here's the minimal version: ```jsx import { useState, useEffect } from "react"; export function CountdownTimer({ seconds }) { const [remaining, setRemaining] = useState(seconds); useEffect(() => { if (remaining <= 0) return; const id = setInterval(() => setRemaining((r) => r - 1), 1000); return () => clearInterval(id); }, [remaining]); return <div>{remaining}s</div>; } ``` **Usage:** ```jsx <CountdownTimer seconds={60} /> ``` It counts down and stops at zero. That's it. --- **Skipped:** pause/resume, reset, onComplete callback, formatting as MM:SS, styling — none were asked for. **Risk:** `seconds` prop changing after mount is ignored; if you need that, reset state with a `key` prop instead (`<CountdownTimer key={seconds} seconds={seconds} />`).

Why it failed: All assertions passed

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email validator | openrouter:anthropic/claude-haiku-4.5Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / email validator | openrouter:anthropic/claude-haiku-4.5 New

Input

{"task":"Write me a Python function that validates email addresses."}

Output

Here's the smallest complete solution: ```python import re def is_valid_email(email): return bool(re.match(r'^[^@]+@[^@]+\.[^@]+$', email)) ``` **What I skipped:** RFC 5322 compliance (allows ~99% of real emails but rejects some edge cases), DNS lookup, internationalized domains, multiple @ signs beyond the pattern, empty local parts. **Risk:** This regex is permissive—`a@b.c` passes. If you need strict validation, use `email_validator` package instead (one line: `validate_email(email)` after `pip install email_validator`). What's your use case—form signup, internal system, or something with real stakes?

Why it failed: All assertions passed

History on main

email validator | openrouter:anthropic/claude-opus-4.8Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / email validator | openrouter:anthropic/claude-opus-4.8 New

Input

{"task":"Write me a Python function that validates email addresses."}

Output

```python import re _EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$") def is_valid_email(email: str) -> bool: return bool(_EMAIL_RE.match(email)) ``` ```python assert is_valid_email("a@b.co") assert not is_valid_email("a@b") assert not is_valid_email("a b@c.com") assert not is_valid_email("@b.co") ``` Skipped: full RFC 5322 compliance — no regex gets that right, and the only real check is sending a confirmation email. Risk: this accepts some technically-invalid addresses and rejects rare valid ones (quoted locals, IP-literal domains). If you need stronger checks, use the `email-validator` package instead of growing this regex.

Why it failed: All assertions passed

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email validator | openrouter:anthropic/claude-sonnet-4.6Ponytail vs caveman vs no-skill: same model, same tasks. Measures code LOC (deterministic) and token / email validator | openrouter:anthropic/claude-sonnet-4.6 New

Input

{"task":"Write me a Python function that validates email addresses."}

Output

```python import re _EMAIL_RE = re.compile(r"[^@\s]+@[^@\s]+\.[^@\s]+") def is_valid_email(email: str) -> bool: return bool(_EMAIL_RE.fullmatch(email)) ``` **Usage** ```python is_valid_email("user@example.com") # True is_valid_email("bad@") # False ``` --- Skipped: RFC 5322 edge cases (quoted locals, IP literals, comments) — almost never needed in practice. Risk: rejects valid but exotic addresses like `"user name"@example.com`; upgrade to a library like [`email-validator`](https://pypi.org/project/email-validator/) if that matters.

Why it failed: All assertions passed

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