Write, run, or repair .NET tests that use xUnit with the right package, CLI, and runner guidance. USE FOR: xUnit v2 or xUnit v3 projects; adding, running, debugging, or repairing xUnit tests; choosing between VSTest and Microsoft.Testing.Platform. DO NOT USE FOR: TUnit projects; MSTest projects. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
SkillScore77Maintained
Automatic
◆QA & Test Engineering pack
Last verified 8/19/2026
What it changes
Passed 15 of 19 test cases with the skill, and 9 of 19 without it.
Without skill45%
With skill77%
Checks it passed that the model alone missed
Identifies the project framework as TUnit
Returns `status: not_applicable` in the output
Returns `status: configured` in the final report
and 5 more in the full report
8 fixed9 passed either way4 still failing1 broke
Pass-rate lift
+32 pp
Tokens
+45%
Agent turns
0%
Response time
-29%
Model gemini-3.6-flashMeasured 8/19/2026v117 of 22 cases passed with skill · 19 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 8 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 8
Prompt
We have a C# test suite built on TUnit in `tests/Services.Tests.csproj`. We need help running and fixing failing assertions in this repository. Please provide status and fix guidance.
What was checked, without and with the skill
Checked
Without skill
With skill
Identifies the project framework as TUnit
Missed
Passed
Returns `status: not_applicable` in the output
Missed
Passed
case-04 · gemini-3.6-flash · 8/19/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md118 lines4 files
xUnit.net
Trigger On
the repo uses xUnit v2 or xUnit v3
you need to add, run, debug, or repair xUnit tests
the team is unsure whether a project is using VSTest or 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
TUnit projects
MSTest projects
generic test strategy with no xUnit-specific mechanics
Inputs
the nearest AGENTS.md
the test project file and package references
the active runner model for the test project
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 active xUnit model before changing commands:
xunit usually means v2
xunit.v3 means v3
xunit.runner.visualstudio plus Microsoft.NET.Test.Sdk usually means VSTest compatibility is enabled
TestingPlatformDotnetTestSupport or UseMicrosoftTestingPlatformRunner means Microsoft.Testing.Platform is in play
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.