negatives

A command for creating missing negative tests for cases in a test suite. A negative test checks that software rejects invalid input or handles an unwanted situation correctly.

In plain words
What is it for?
Use it to find cases without negative tests, work through them one at a time, review progress, skip or reset cases, and author the required test files.
Why use it?
It exposes gaps where code may work for normal input but fail on errors, misuse, or boundary cases. Unclear decisions are sent to the user instead of being guessed.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/ecro/embedeval/negatives
Clone the repo
git clone --depth 1 https://github.com/Ecro/embedeval

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,418 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.03418
Opus 5 $0.00000 $0.01709
Sonnet 5 $0.00000 $0.00684
Haiku 4.5 $0.00000 $0.00342

Measured yesterday against content hash 05f729e95dd5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

negatives scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/negatives.md · 310 lines

How it starts

The opening of the file, as written. The whole thing — 310 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/negatives — Interactive mutation-oracle authoring

Communication Protocol

  • Be direct. No preamble, no ceremony, no encouragement.
  • Show the user concrete content (code, check names, reference snippets) before asking questions.
  • Ask ONE decision per AskUserQuestion call — never batch multiple unrelated decisions.
  • Never guess judgment calls. If unclear, ask.
  • Never skip the oracle gate. A negative that doesn't pass oracle is not landed.

Sequentially author negatives.py for every case that lacks one, with interactive judgment gates where LLM cannot reliably decide.


Usage

/negatives                         # sync + resume — work the next pending case
/negatives --status                # sync + print progress table and exit
/negatives --case TC_ID            # sync + work a specific case
/negatives --category dma          # sync + cycle pending cases in a category
/negatives --sync                  # ONLY reconcile progress file with cases/, print diff, exit
/negatives --skip TC_ID reason     # mark TC as skipped with reason (won't revisit)
/negatives --reset TC_ID           # re-open a done case
/negatives --init                  # nuke progress file and rebuild from scratch (destructive)

Every invocation runs auto-sync first — the progress file is always reconciled with the current cases/ directory before any action. Newly added TCs (from Yocto/Linux expansion, new categories, etc.) appear automatically as pending without manual bookkeeping. Removed TCs are flagged as orphaned (not deleted — may be a rename/typo).


Progress File

Location: plans/negatives-progress.json

Schema:

{
  "version": 1,
  "generated": "YYYY-MM-DD",
  "cases": [
    {
      "case_id": "dma-002",
      "category": "dma",
      "priority": 1,
      "status": "pending | in-progress | done | skipped | orphaned",
      "started_at": "YYYY-MM-DD" or null,
      "completed_at": "YYYY-MM-DD" or null,
      "notes": "skip reason or oracle warnings" or null
    }
  ]
}

Read the full file on GitHub · 310 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 310 lines · 0 tokens per session scan A 05f729e95dd5

Subscribe to this mod's changes

negatives is a command published in the GitHub repository Ecro/embedeval (11 stars, last pushed 26d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 3,418 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.