agentmods.dev

fuzzing-test

fuzzing-test is a skill for Claude Code from johnqtcg/awesome-skills. It costs 74 tokens per session (5,984 once invoked), scanned A, original, MIT.

A Go testing guide for generating fuzz tests, which repeatedly try varied inputs to find crashes and unexpected behavior. It first checks whether the code is suitable for fuzzing.

In plain words
What is it for?
It helps create Go 1.18+ fuzz tests for parsers and other suitable code, investigate crashes, set up continuous integration runs, and diagnose slow or ineffective fuzzing.
Why use it?
It prevents writing fuzz tests for targets that lack a useful way to detect incorrect results. It also helps focus testing on parser robustness, round-trip behavior, or differences between implementations.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

not rated 30repo changed 1mo ago A scan SkillSpector: warn 74 tokens original MIT

Good fit It helps create Go 1.18+ fuzz tests for parsers and other suitable code, investigate crashes, set up continuous integration runs, and diagnose slow or ineffective fuzzing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/johnqtcg/awesome-skills/fuzzing-test
View source ↗ johnqtcg/awesome-skills johnqtcg.github.io
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.

Any agent
npx skills add johnqtcg/awesome-skills --skill fuzzing-test
Clone the repo
git clone --depth 1 https://github.com/johnqtcg/awesome-skills

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fuzzing-test

README.md
[![agentmods](https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test/github.svg)](https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test)
Your own site
<a href="https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test"><img src="https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for fuzzing-test

Your own site · 80×15
<a href="https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test"><img src="https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,984 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium analysis-evasion · line 1
    Suspicious Unicode normalization or mixed-script content
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
How audits are shown
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 5.1 $0.00074 $0.05984
Opus 5.5 $0.00030 $0.02394
Sonnet 5.5 $0.00015 $0.01197
Haiku 4.5 $0.00007 $0.00598

Measured 1mo ago against content hash b101c72fed42, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fuzzing-test 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 1mo ago.

The scan reads SKILL.md. This mod also ships 5 executable files (scripts/run_regression.sh, scripts/tests/test_golden_scenarios.py, scripts/tests/test_llm_fuzz_eval.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/fuzzing-test/SKILL.md · 516 lines

How it starts

The opening of the file, as written. The whole thing — 516 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fuzzing Test Skill (Go)

Generate high-signal Go fuzz tests only when targets are suitable.

Quick Reference — Load References Selectively

Read the section named below first; load the reference only when its trigger applies.

When you need to… Section Load on demand
Decide if a target is suitable §Applicability Gate (run first, always) applicability-checklist.md — full decision tree, oracle forms, version gate, borderline cases
Choose among 3+ candidate targets §Target Priority Gate target-priority.md — bug-yield ranking and tie-breaks
Write the harness §Minimal Templates —
Handle a discovered crash §Crash Handling crash-handling.md — triage steps, corpus policy, report template
Set up CI §CI Strategy ci-strategy.md — Actions config, corpus caching, budgets
Diagnose a slow/ineffective run, OOM, leak, or flake §Fuzz Performance Baseline advanced-tuning.md — seed quality, skip-rate, allocation profiling
Avoid or check for common mistakes §Quality Scorecard anti-examples.md — 9 BAD/GOOD harness patterns

Applicability Gate (Must Run First)

Before writing any fuzz code, evaluate suitability. If the target fails this gate, the entire remaining workflow is skipped — output the verdict, suggest alternatives, and stop.

Mark each item Pass / Fail:

  1. Target has meaningful input space (not trivial fixed-path logic).
  2. Target can be driven by Go fuzz-supported parameter types.
  3. Target has clear oracle/invariant:
    • no panic for any input
    • round-trip (decode(encode(x)) == x)
    • differential consistency
    • domain constraints/properties
  4. Target is mostly deterministic/local (not dominated by DB/network/clock/global mutable state).
  5. Target is fast enough for high-iteration fuzzing.

Hard stop — items 1, 2, and 3 are each independently blocking: without a meaningful input space fuzzing finds nothing a table test would not; without fuzz-supported types the fuzzer cannot drive the target; without an oracle a bug cannot be recognised when the input triggers it. On any of those:

  • output Applicability Verdict: Not suitable for fuzzing
  • list concrete failed checks with specific code references
  • suggest alternative strategy (unit/integration/property tests)
  • stop (do not write fuzz tests)

Read the full file on GitHub · 516 lines

Files

What ships with it

52 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 1mo ago Changed · -21 lines b101c72fed42
  2. 1mo ago Changed · +52 lines 3fd881cc334f
  3. 1mo ago First seen · 485 lines · 74 tokens per session scan A f8e0bae854af

Subscribe to this mod's changes

fuzzing-test is a skill published in the GitHub repository johnqtcg/awesome-skills (30 stars, last pushed 16d ago), licensed MIT. It adds 74 tokens to every session and 5,984 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-30.

Claude CodeGoLanguagesTestingUnit testingagentsai-assistantai-skillsanthropicdeveloper-tools
Related

Other skills, from other repositories

golang-testing

Go testing best practices including table-driven tests, test helpers, benchmarking, race detection, coverage analysis, and integration testing patterns. Use when writing or improving Go tests.

affaan-m/ECC · 37 tokens

golang-testing-patterns

Modern Go testing patterns including table-driven tests, subtests, test organization, and best practices. Use when writing or refactoring tests, implementing test coverage, or when the user asks about Go testing approaches.

codeready-toolchain/tarsy · 47 tokens

test-go

Write, review, and improve Go test code for this project. Use whenever generating, reviewing, or modifying Go tests - including when invoked by the Tester agent, the /test prompt, or any test-related request. Covers table-driven tests, subtests, t.Parallel(), test helpers with t.Helper(), error assertions via…

sergeyklay/.agents · 109 tokens

go-testing

Use when writing, reviewing, or improving Go test code — including table-driven tests, subtests, parallel tests, test helpers, test doubles, and assertions with cmp.Diff. Also use when a user asks to write a test for a Go function, even if they don't mention specific patterns like table-driven tests or subtests. Does…

cxuu/golang-skills · 80 tokens

golang-stretchr-testify

Comprehensive guide to stretchr/testify for Golang testing. Covers assert, require, mock, and suite packages in depth. Use when writing tests with testify, creating mocks, setting up test suites, or choosing between assert and require. Covers testify assertions, mock expectations, argument matchers, call verification…

aiskillstore/marketplace · 97 tokens

go-testing-with-testify

Write, review, or harden Go tests using stretchr/testify assert, require, mock, or suite. Use for assertion choice, test doubles, subtests, concurrency, and flake triage in an existing Go test setup. Use coding-guidance-go for production code or non-testify tests and tester-mindset for test strategy without concrete…

n-n-code/n-n-code-skills · 79 tokens