| name | dotnet-xunit |
| version | 1.0.0 |
| category | Testing |
| description | Write, run, or repair .NET tests that use xUnit. Use when a repo uses `xunit`, `xunit.v3`, `[Fact]`, `[Theory]`, or `xunit.runner.visualstudio`, and you need the right CLI, package, and runner guidance for xUnit on VSTest or Microsoft.Testing.Platform. |
| compatibility | Requires a .NET solution or project with xUnit packages; respects the repo's `AGENTS.md` commands first. |
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.
- Keep the runner model consistent:
- xUnit v2 usually runs through VSTest
- xUnit v3 can run as a standalone executable with
dotnet run
- xUnit v3 can also integrate with Microsoft.Testing.Platform
- do not mix VSTest-only switches into Microsoft.Testing.Platform runs
- Run the narrowest useful scope first:
- one project
- one class
- one trait
- one method
- Prefer
[Theory] for stable data-driven coverage and [Fact] for single-path invariant checks.
- Keep
xunit.analyzers enabled when present. Fix analyzer findings instead of muting them casually.
Bootstrap When Missing
If xUnit is requested but not configured:
- Detect current framework first:
rg -n "xunit(\\.v3)?|xunit\\.runner\\.visualstudio|TestingPlatformDotnetTestSupport|UseMicrosoftTestingPlatformRunner|TUnit|MSTest" -g '*.csproj' .
- If the repo currently uses
TUnit or MSTest, do not auto-migrate. Return status: not_applicable unless migration is explicitly requested.
- For explicit xUnit adoption, add packages to the target test project:
dotnet add TEST_PROJECT.csproj package xunit.v3
- optional VSTest bridge:
dotnet add TEST_PROJECT.csproj package xunit.runner.visualstudio
- Add repo test commands and runner notes to
AGENTS.md.
- Run
dotnet test TEST_PROJECT.csproj or repo-defined xUnit command and return status: configured or status: improved.
Deliver
- xUnit tests that match the repo's active xUnit version and runner
- commands that work in local and CI runs
- focused verification before broader suite execution
Validate
- the chosen CLI matches the active runner model
- test filters or focused runs are valid for that runner
- tests use deterministic inputs and assertions
- xUnit-specific analyzers remain active unless the repo documents an exception
Ralph Loop
Use the Ralph Loop for every task, including docs, architecture, testing, and tooling work.
- Plan first (mandatory):
- analyze current state
- define target outcome, constraints, and risks
- write a detailed execution plan
- list final validation skills to run at the end, with order and reason
- Execute one planned step and produce a concrete delta.
- Review the result and capture findings with actionable next fixes.
- Apply fixes in small batches and rerun the relevant checks or review steps.
- Update the plan after each iteration.
- Repeat until outcomes are acceptable or only explicit exceptions remain.
- If a dependency is missing, bootstrap it or return
status: not_applicable with explicit reason and fallback path.
Required Result Format
status: complete | clean | improved | configured | not_applicable | blocked
plan: concise plan and current iteration step
actions_taken: concrete changes made
validation_skills: final skills run, or skipped with reasons
verification: commands, checks, or review evidence summary
remaining: top unresolved items or none
For setup-only requests with no execution, return status: configured and exact next commands.
Load References
references/xunit.md
references/patterns.md
references/anti-patterns.md
Example Requests
- "Run this xUnit suite correctly."
- "Fix our xUnit v3 test command."
- "Add an xUnit regression test and keep CI compatible."