verify-tests-fail-without-fix

verify-tests-fail-without-fix is a skill for Claude Code, Codex from dotnet/maui. It costs 60 tokens per session (2,578 once invoked), scanned A, original, MIT.

A test-checking skill that verifies a test reproduces a bug before the code is fixed. It recognizes UI, device, unit, and XAML tests and uses the matching test runner.

In plain words
What is it for?
Checking bug-reproduction tests and, in its full mode, validating that the later fix makes those tests pass.
Why use it?
It catches tests that pass even when the bug is still present, helping confirm that a test can detect the actual problem.

Skill for Claude CodeCodex

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

About the project

.NET MAUI is a C# and XAML framework for building native mobile and desktop applications from one shared codebase. Developers use it to create apps for Android, iOS, iPadOS, macOS, and Windows. The catalogue entries provide skills, instructions, and agents for working with .NET MAUI.

dotnet/maui · 23,319 stars · on GitHub · dot.net

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 skills/dotnet/maui/verify-tests-fail-without-fix
Any agent
npx skills add dotnet/maui --skill verify-tests-fail-without-fix
Clone the repo
git clone --depth 1 https://github.com/dotnet/maui

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 verify-tests-fail-without-fix

README.md
[![agentmods](https://agentmods.dev/badge/skills/dotnet/maui/verify-tests-fail-without-fix.svg)](https://agentmods.dev/skills/dotnet/maui/verify-tests-fail-without-fix)
Your own site
<a href="https://agentmods.dev/skills/dotnet/maui/verify-tests-fail-without-fix"><img src="https://agentmods.dev/badge/skills/dotnet/maui/verify-tests-fail-without-fix.svg" alt="Measured on agentmods" height="20"></a>
Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,578 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 5.1 $0.00060 $0.02578
Opus 5 $0.00030 $0.01289
Sonnet 5 $0.00012 $0.00516
Haiku 4.5 $0.00006 $0.00258

Measured 6d ago against content hash a44812682070, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

verify-tests-fail-without-fix 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 6d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/verify-tests-fail.ps1, scripts/Verify-TestsFail.Tests.ps1), 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.

.github/skills/verify-tests-fail-without-fix/SKILL.md · 265 lines

How it starts

The opening of the file, as written. The whole thing — 265 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Verify Tests Fail Without Fix

Verifies tests actually catch the issue. Supports all test types (UI tests, unit tests, XAML tests, device tests) and two workflow modes.

Supported Test Types

Test Type Auto-Detected From Runner
UITest TestCases.Shared.Tests/, TestCases.HostApp/ BuildAndRunHostApp.ps1
DeviceTest DeviceTests/ Run-DeviceTests.ps1
UnitTest *.UnitTests/, Graphics.Tests/ dotnet test
XamlUnitTest Xaml.UnitTests/ dotnet test

Test type is auto-detected from changed files. Override with -TestType if needed.

-Platform is required for UI and Device tests. It selects which platform to verify the fix on. Unit and XAML tests do not require -Platform.

Activation Guard

🛑 This skill ONLY verifies that existing tests reproduce a bug. Do NOT activate for:

  • Writing new tests → use write-tests-agent
  • Running tests without verification context → use run-device-tests
  • Code review → use code-review skill
  • General test advice

Requires: a platform and either test files in the PR or an explicit TestFilter.

⚠️ CRITICAL: Inverted Pass/Fail Semantics

In this skill, test outcomes mean the OPPOSITE of normal:

Test Result (without fix) Verification Result Why
Tests FAIL ✅ GOOD Tests detect the bug
Tests PASS ❌ BAD Tests miss the bug

NEVER say "verification passed" when tests PASS without the fix.

Workflow

Interpretation-Only Requests

If the caller asks how to read or report verification output, explain the result contract below without running the script. Do not turn a question about result semantics into a verification run.

Step 1: Determine Mode

  • Check if fix files exist in the PR (non-test code changes detected by the script from the git diff)
  • If fix files present → Full Verification mode (-RequireFullVerification)
  • If no fix files → Verify Failure Only mode (omit the flag)

Read the full file on GitHub · 265 lines

Files

What ships with it

4 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. 6d ago First seen · 265 lines · 60 tokens per session scan A a44812682070

Subscribe to this mod's changes

verify-tests-fail-without-fix is a skill published in the GitHub repository dotnet/maui (23,319 stars, last pushed today), licensed MIT. It adds 60 tokens to every session and 2,578 once invoked, about $0.0003 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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