Skills platform-detection

Name: platform-detection
Author: dotnet

Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need detection logic.

install

source · Clone the upstream repo

git clone https://github.com/dotnet/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/dotnet/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/dotnet-test/skills/platform-detection" ~/.claude/skills/dotnet-skills-platform-detection && rm -rf "$T"

manifest: plugins/dotnet-test/skills/platform-detection/SKILL.md

source content

Test Platform and Framework Detection

Determine which test platform (VSTest or Microsoft.Testing.Platform) and which test framework (MSTest, xUnit, NUnit, TUnit) a project uses.

Detection files to always check (in order):

global.json

→

.csproj

→

Directory.Build.props

→

Directory.Packages.props

Detecting the test framework

Read the

.csproj

file and

Directory.Build.props

Directory.Packages.props

(for centrally managed dependencies) and look for:

Package or SDK reference	Framework
`MSTest` (metapackage, recommended) or `<Sdk Name="MSTest.Sdk">`	MSTest
`MSTest.TestFramework` + `MSTest.TestAdapter`	MSTest (also valid for v3/v4)
`xunit` , `xunit.v3` , `xunit.v3.mtp-v1` , `xunit.v3.mtp-v2` , `xunit.v3.core.mtp-v1` , `xunit.v3.core.mtp-v2`	xUnit
`NUnit` + `NUnit3TestAdapter`	NUnit
`TUnit`	TUnit (MTP only)

Detecting the test platform

The detection logic depends on the .NET SDK version. Run

dotnet --version

to determine it.

.NET SDK 10+

On .NET 10+, the

global.json

test.runner

setting is the authoritative source:

global.json

contains

"test": { "runner": "Microsoft.Testing.Platform" }

→ MTP

If
```
global.json
```
has
```
"runner": "VSTest"
```
, or no
```
test
```
section exists → VSTest

Important: On .NET 10+,
<TestingPlatformDotnetTestSupport>
alone does not switch to MTP. The
global.json
runner setting takes precedence. If the runner is VSTest (or unset), the project uses VSTest regardless of
TestingPlatformDotnetTestSupport
.

.NET SDK 8 or 9

On older SDKs, check these signals in priority order:

1. Check the

<TestingPlatformDotnetTestSupport>

MSBuild property. Look in the

.csproj

Directory.Build.props

, and

Directory.Packages.props

. If set to

true

in any of these files, the project uses MTP.

Critical: Always read
Directory.Build.props
and
Directory.Packages.props
if they exist. MTP properties are frequently set there instead of in the
.csproj
, so checking only the project file will miss them.

2. Check project-level signals:

Signal	Platform
`<Sdk Name="MSTest.Sdk">` as project SDK	MTP by default
`<UseMicrosoftTestingPlatformRunner>true</UseMicrosoftTestingPlatformRunner>`	MTP runner (xUnit)
`<EnableMSTestRunner>true</EnableMSTestRunner>`	MTP runner (MSTest)
`<EnableNUnitRunner>true</EnableNUnitRunner>`	MTP runner (NUnit)
`Microsoft.Testing.Platform` package referenced directly	MTP
`TUnit` package referenced	MTP (TUnit is MTP-only)

Note: The presence of
Microsoft.NET.Test.Sdk
does not necessarily mean VSTest. Some frameworks (e.g., MSTest) pull it in transitively for compatibility, even when MTP is enabled. Do not use this package as a signal on its own — always check the MTP signals above first. Key distinction: VSTest is the classic platform that uses
vstest.console
under the hood. Microsoft.Testing.Platform (MTP) is the newer, faster platform. Both can be invoked via
dotnet test
, but their filter syntax and CLI options differ.