A .NET testing guide for MSTest, Microsoft's test framework for C# and other .NET languages. It covers test attributes, data-driven tests, test runners, project styles, and moving between runner models.

Writing, running, debugging, repairing, or configuring MSTest tests and integrating them with local commands or continuous integration.

MSTest projects can use different SDK, package, and runner setups, which affects discovery and execution. The guide helps align new or repaired tests with the repository's real configuration.

mstest — Skill for Claude Code and Codex by managedcode

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 managedcode/dotnet-skills --skill mstest

Clone the repo

git clone --depth 1 https://github.com/managedcode/dotnet-skills

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/managedcode/dotnet-skills/mstest/github.svg)](https://agentmods.dev/skills/managedcode/dotnet-skills/mstest)

Your own site

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/mstest"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/mstest/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/mstest"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/mstest.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 139 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,199 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.

Model	Per session	Once invoked
Fable 5.1	$0.00139	$0.01199
Opus 5	$0.00069	$0.00600
Sonnet 5	$0.00028	$0.00240
Haiku 4.5	$0.00014	$0.00120

Measured 9d ago against content hash 8fd065d630ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

mstest 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 9d 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

dotnet-mstest — 91% identical, 13 lines differ
mcaf-dotnet-mstest — 89% identical, 11 lines differ

catalog/Testing/MSTest/skills/mstest/SKILL.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MSTest

Trigger On

the repo uses MSTest
you need to add, run, debug, or repair MSTest tests
the repo is moving between VSTest and Microsoft.Testing.Platform

Value

produce a concrete project delta: code, docs, config, tests, CI, or review artifact
reduce ambiguity through explicit planning, verification, and final validation skills
leave reusable project context so future tasks are faster and safer

Do Not Use For

xUnit projects
TUnit projects
generic test strategy with no MSTest-specific mechanics

Inputs

the nearest AGENTS.md
the test project file and package references
the active MSTest runner model

Quick Start

Read the nearest AGENTS.md and confirm scope and constraints.
Run this skill's Workflow through the Ralph Loop until outcomes are acceptable.
Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

Detect the MSTest project style first:
- MSTest.Sdk project SDK
- MSTest meta-package
- legacy package set with explicit Microsoft.NET.Test.Sdk
Read the repo's real test command from AGENTS.md. If the repo has no explicit command yet, start with dotnet test PROJECT_OR_SOLUTION.
Keep the runner model consistent:
- MSTest.Sdk defaults to the MSTest runner on Microsoft.Testing.Platform
- VSTest is opt-in with UseVSTest=true or legacy package choices
- do not pass VSTest-only switches or assume legacy .runsettings behavior on Microsoft.Testing.Platform jobs
Prefer [DataRow] or DynamicData for stable data-driven coverage. Keep test lifecycle hooks minimal and deterministic.
Keep MSTest analyzers enabled and fix findings instead of muting them casually.
Align coverage/reporting packages with the active runner.

Bootstrap When Missing

If MSTest is requested but not configured:

Detect current framework first:
- rg -n "MSTest\\.Sdk|PackageReference Include=\"MSTest\"|xunit|TUnit|UseVSTest|TestingPlatformDotnetTestSupport" -g '*.csproj' .
If the repo currently uses xUnit or TUnit, do not auto-migrate. Return status: not_applicable unless migration is explicitly requested.
For explicit MSTest adoption, add package(s) to target test project:
- dotnet add TEST_PROJECT.csproj package MSTest
Document runner model (MSTest.Sdk default MTP vs UseVSTest) in AGENTS.md.
Run dotnet test TEST_PROJECT.csproj and return status: configured or status: improved.

Read the full file on GitHub · 117 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.

9d ago First seen · 117 lines · 139 tokens per session scan A 8fd065d630ed

Subscribe to this mod's changes

mstest is a skill published in the GitHub repository managedcode/dotnet-skills (479 stars, last pushed 7d ago), licensed MIT. It adds 139 tokens to every session and 1,199 once invoked, about $0.0007 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 2026-09-03.

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