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.
npx skills add peterblazejewicz/claude-plugins --skill test-driven-developmentgit clone --depth 1 https://github.com/peterblazejewicz/claude-pluginsWrote 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.
[](https://agentmods.dev/skills/peterblazejewicz/claude-plugins/test-driven-development)<a href="https://agentmods.dev/skills/peterblazejewicz/claude-plugins/test-driven-development"><img src="https://agentmods.dev/badge/skills/peterblazejewicz/claude-plugins/test-driven-development/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.
<a href="https://agentmods.dev/skills/peterblazejewicz/claude-plugins/test-driven-development"><img src="https://agentmods.dev/badge/skills/peterblazejewicz/claude-plugins/test-driven-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00103 | $0.06792 |
| Opus 5.5 | $0.00041 | $0.02717 |
| Sonnet 5.5 | $0.00021 | $0.01358 |
| Haiku 4.5 | $0.00010 | $0.00679 |
Grade A, and why
test-driven-development 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.
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.
How it starts
The opening of the file, as written. The whole thing — 523 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-Driven Development
Overview
Write a failing test before writing the code that makes it pass. For bug fixes, reproduce the bug with a test before attempting a fix. Tests are proof — "seems right" is not done. A codebase with good tests is an AI agent's superpower; a codebase without tests is a liability.
When to Use
- Implementing any new logic or behavior
- Fixing any bug (the Prove-It Pattern)
- Modifying existing functionality
- Adding edge case handling
- Any change that could break existing behavior
When NOT to use: Pure configuration changes, documentation updates, or static content changes that have no behavioral impact.
Related: For HTTP and UI integration, combine TDD with integration-testing-dotnet — that skill covers WebApplicationFactory<T>, Testcontainers, Microsoft.Playwright, and Avalonia.Headless for Blazor / ASP.NET Core / Avalonia tests respectively.
Version Awareness: xUnit v2 vs v3, and Microsoft.Testing.Platform
The guidance below works with both current xUnit major versions and both current runners. Detect which one the project uses (the .csproj package references are the tell) and apply the matching packaging.
| Aspect | xUnit v2 (mature) | xUnit v3 (current) |
|---|---|---|
| Core package | xunit |
xunit.v3 |
| IDE / VSTest runner | xunit.runner.visualstudio |
xunit.v3.runner.visualstudio |
Output of dotnet build on the test project |
DLL loaded by the runner | Executable (can be run directly: ./MyApp.Tests.exe) |
| Native runner | VSTest (dotnet test) |
Microsoft.Testing.Platform (MTP) — faster startup, self-contained; still invokable via dotnet test |
| Minimum target framework | netcoreapp3.1+ / net472 | net8.0 or later |
| Source-level API compatibility | [Fact], [Theory], [InlineData], Assert.*, IClassFixture<T>, ICollectionFixture<T>, [Collection] — all identical between v2 and v3 for normal test code |
same |
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.
- 1mo ago First seen · 523 lines · 103 tokens per session scan A a7d7de70c6fa
test-driven-development is a skill published in the GitHub repository peterblazejewicz/claude-plugins (8 stars, last pushed 4mo ago), licensed MIT. It adds 103 tokens to every session and 6,792 once invoked, about $0.0004 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 2026-08-31.
Other skills, from other repositories
nw-fp-fsharp
F# language-specific patterns, Railway-Oriented Programming, and Computation Expressions.
build-and-test
How to build and test .NET projects in the Agent Framework repository. Use this when verifying or testing changes.
verify-dotnet-samples
How to build, run and verify the .NET sample projects in the Agent Framework repository. Use this when a user wants to verify that the samples still function as expected.
migrate-mstest-v3-to-v4
Use this skill before answering, planning, or editing any MSTest 3.x-to-4.x upgrade or post-upgrade failure. Triggers include "MSTest v4 breaking changes"; CS0507/CS0103/CS1061/CS1615; ExecuteAsync, CallerInfo, DisplayName, or custom TestMethodAttribute; ClassCleanupBehavior; ContainsKey; ThrowsExactly or…
migrate-xunit-to-mstest
Convert .NET tests from xUnit.net v2/v3 to MSTest v4 while preserving VSTest or MTP. Use for replacing xunit packages, Fact/Theory/InlineData/MemberData, assertions, IClassFixture/ICollectionFixture, ITestOutputHelper, TestContext cancellation, traits/Owner, skips, timeouts, and xUnit parallelization. Also use when a…
migrate-xunit-to-xunit-v3
Migrate .NET test projects from xUnit.net v2 to xunit.v3 and fix v3 breaks. Use for package/CPM conversion, OutputType=Exe, preserving the VSTest or MTP runner (including projects currently using YTest.MTP.XUnit2), incompatible TFMs, async void tests, string-to-Type attributes, custom Fact/Theory/BeforeAfterTest…