bug-reproduction-test-generator

bug-reproduction-test-generator is a skill for Claude Code, Codex from ArabelaTso/Skills-4-SE. It costs 104 tokens per session (1,537 once invoked), scanned A, original, Apache-2.0.

A tool for turning a bug report, error message, stack trace, or code repository into an executable test that demonstrates the problem. The test uses the project's existing testing framework.

In plain words
What is it for?
Use it to create focused failing tests for incorrect results, exceptions, crashes, or assertion failures. It examines the affected code, entry points, test setup, and conditions that trigger the bug.
Why use it?
It makes a reported bug reproducible, so developers can confirm the failure and check whether a fix actually solves it.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create focused failing tests for incorrect results, exceptions, crashes, or assertion failures. It examines the affected code, entry points, test setup, and conditions that trigger the bug.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/arabelatso/skills-4-se/bug-reproduction-test-generator
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 ArabelaTso/Skills-4-SE --skill bug-reproduction-test-generator
Clone the repo
git clone --depth 1 https://github.com/ArabelaTso/Skills-4-SE

Made for: Claude Code, Codex.

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 bug-reproduction-test-generator

README.md
[![agentmods](https://agentmods.dev/badge/skills/arabelatso/skills-4-se/bug-reproduction-test-generator/github.svg)](https://agentmods.dev/skills/arabelatso/skills-4-se/bug-reproduction-test-generator)
Your own site
<a href="https://agentmods.dev/skills/arabelatso/skills-4-se/bug-reproduction-test-generator"><img src="https://agentmods.dev/badge/skills/arabelatso/skills-4-se/bug-reproduction-test-generator/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 bug-reproduction-test-generator

Your own site · 80×15
<a href="https://agentmods.dev/skills/arabelatso/skills-4-se/bug-reproduction-test-generator"><img src="https://agentmods.dev/badge/skills/arabelatso/skills-4-se/bug-reproduction-test-generator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 104 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,537 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 pass 7 Sept 2026
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 $0.00104 $0.01537
Opus 5 $0.00052 $0.00768
Sonnet 5 $0.00021 $0.00307
Haiku 4.5 $0.00010 $0.00154

Measured 11d ago against content hash ac6e0afee709, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

bug-reproduction-test-generator 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 11d ago.

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/bug-reproduction-test-generator/SKILL.md · 217 lines

How it starts

The opening of the file, as written. The whole thing — 217 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Bug Reproduction Test Generator

Generate executable tests that reproduce reported bugs based on issue reports and code repositories.

Workflow

Follow these steps to generate a bug reproduction test:

1. Analyze the Issue Report

Extract key information from the issue report:

  • Symptoms: What goes wrong? (incorrect output, exception, crash, assertion failure, unexpected behavior)
  • Affected components: Which modules, classes, or functions are involved?
  • Triggering conditions: What inputs, states, or sequences trigger the bug?
  • Stack traces: If provided, identify the call chain and failure point
  • Expected vs. actual behavior: What should happen vs. what actually happens?

2. Inspect the Repository

Identify relevant code and context:

  • Locate the affected components mentioned in the issue
  • Find entry points (public APIs, main functions, test fixtures)
  • Understand dependencies and required setup
  • Identify the test framework used (pytest, unittest, JUnit, Jest, etc.)
  • Check existing test patterns for consistency

3. Generate the Reproduction Test

Create a minimal, focused test that:

Test structure:

  • Uses the repository's existing test framework and conventions
  • Sets up minimal preconditions needed to trigger the bug
  • Executes the code path that triggers the bug
  • Asserts the symptom described in the issue report

Assertions:

  • For exceptions: Assert the exception type and message match the report
  • For incorrect output: Assert actual output matches the reported incorrect behavior
  • For crashes: Assert the crash occurs at the expected point
  • For assertion failures: Reproduce the failing assertion

Documentation:

  • Add inline comments explaining the reproduction logic
  • Reference the issue number/URL in the test name or docstring
  • Document any assumptions made due to underspecified details

4. Output Format

Provide:

  1. Executable test code in the appropriate language and framework
  2. Inline comments explaining how the test reproduces the bug
  3. Markdown summary including:
    • How the test reproduces the issue
    • Which symptoms it validates
    • Any assumptions made
    • Instructions for running the test

Read the full file on GitHub · 217 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. 11d ago First seen · 217 lines · 104 tokens per session scan A ac6e0afee709

Subscribe to this mod's changes

bug-reproduction-test-generator is a skill published in the GitHub repository ArabelaTso/Skills-4-SE (252 stars, last pushed 21d ago), licensed Apache-2.0. It adds 104 tokens to every session and 1,537 once invoked, about $0.0005 per session on Opus 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.

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