TDD Guide
alirezarezvani/claude-skills
Test-driven development skill for writing unit tests, generating test fixtures and mocks, analyzing coverage gaps, and guiding red-green-refactor workflows across Jest, Pytest, JUnit, Vitest, and…
Analyzes test suites in any language and tags each test with a standardized set of traits (positive, negative, critical-path, boundary, smoke, regression, integration, performance, security).
$ npx skills add microsoft/testfx --skill test-tagging -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install microsoft/testfx test-tagging --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/test-tagging .claude/skills/test-tagging && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .claude/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/microsoft/testfx/tree/main/.agents/skills/test-taggingType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add microsoft/testfx --skill test-tagging -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install microsoft/testfx test-tagging --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/test-tagging .agents/skills/test-tagging && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .agents/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/testfx --skill test-tagging -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install microsoft/testfx test-tagging --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/test-tagging .cursor/skills/test-tagging && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .cursor/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/microsoft/testfx.git --path .agents/skills/test-tagging--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add microsoft/testfx --skill test-tagging -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install microsoft/testfx test-tagging --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/test-tagging .gemini/skills/test-tagging && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .gemini/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install microsoft/testfx test-taggingInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add microsoft/testfx --skill test-tagging -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/test-tagging .github/skills/test-tagging && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .github/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/testfx --skill test-tagging -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install microsoft/testfx test-tagging --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/test-tagging .opencode/skills/test-tagging && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "test-tagging" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/test-tagging into .opencode/skills/test-tagging/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "test-tagging", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
test-taggingAnalyzes test suites in any language and tags each test with a standardized set of traits (positive, negative, critical-path, boundary, smoke, regression, integration, performance, security).
Test Tagging is an agent skill from microsoft/testfx, published by the product's own GitHub organization. Analyzes test suites in any language and tags each test with a standardized set of traits (positive, negative, critical-path, boundary, smoke, regression, integration, performance, security). Use when the user wants to categorize, audit, or label tests with traits. Works with .NET (MSTest TestCategory / xUnit Trait / NUnit Category / TUnit Property), Python (pytest markers; unittest has no canonical tag syntax so report-only), TypeScript/JavaScript (Jest/Vitest test names, describe-block conventions), Java (JUnit…
Its SKILL.md is about 4.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Unit testing and Test generation. It works with JUnit, TypeScript, .NET and Jest. The repository describes itself as: This repository holds the source code of Microsoft.Testing.Platform (MTP), a lightweight alternative to VSTest, as well as MSTest adapter and framework. The licence is MIT.
5 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 44b9dcc. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Shell commands in SKILL.md call:
godotnetpytestmvncargonpmFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Test Tagging loads about 4.3k tokens when it runs. Until then it costs about 254 tokens; SKILL.md has 1,641 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
The full file from microsoft/testfx at commit 44b9dcc, republished under its MIT licence (© microsoft). 1,641 words, ~4,327 tokens.
.claude/skills/test-tagging/SKILL.md (or your agent's skills folder).Analyze an existing test suite in any supported language and apply a standardized set of trait tags to each test method, giving teams visibility into their test distribution (positive vs. negative, critical-path coverage, smoke tests, etc.).
Language-specific guidance: Call the
test-analysis-extensionsskill to discover available extension files, then read the file matching the target codebase. The extension file documents framework-specific tag attributes and a "tag-support capability" (auto-edit, report-only, or convention-based) that drives whether this skill modifies source files or only emits a report.
code-testing-agent for any language, or writing-mstest-tests for MSTest)run-tests for .NET; equivalent native runners elsewhere)| Input | Required | Description |
|---|---|---|
| Test project or files | Yes | Path to the test project, folder, or specific test files to analyze |
| Scope | No | tag (apply attributes when language supports auto-edit), audit (report only), or both (default: both). For languages with no canonical tag syntax, the skill emits a report regardless of scope. |
| Framework | No | Auto-detected. Override when detection fails. |
Use exactly these trait names and values. Do not invent new trait values outside this table.
| Trait Value | Meaning | Heuristics |
|---|---|---|
positive | Verifies expected behavior under normal/valid conditions | Asserts success, valid output, expected state, no exceptions for valid input |
negative | Verifies correct handling of invalid input, errors, or edge cases | Asserts exceptions, error codes, validation failures, rejects bad input |
boundary | Tests limits, thresholds, empty/null/None/nil inputs, min/max values | Operates on 0, -1, int.MaxValue / sys.maxsize / Number.MAX_SAFE_INTEGER / math.MaxInt64 / i32::MAX, empty string, null/None/nil/undefined, empty collection, boundary of valid range |
critical-path | Core workflow that must never break; breakage blocks users | Tests the primary success scenario of a key public API or user-facing feature |
smoke | Quick sanity check that the system is operational | Fast, no complex setup, verifies basic wiring (e.g., service resolves, endpoint returns 200) |
regression | Reproduces a specific previously-reported bug | References a bug ID, issue number, or describes a fix in its name or comments |
integration | Crosses process, network, or persistence boundaries | Uses real database, HTTP client, file system, external service, or multi-component setup |
end-to-end | Full user workflow spanning the entire application stack | Exercises a complete scenario from entry point to final result, distinct from single-boundary integration |
performance | Validates timing, throughput, or resource consumption | Asserts on elapsed time, memory, allocations, or uses benchmark harness (BenchmarkDotNet, pytest-benchmark, benchmark.js, JMH, go test -bench, criterion.rs, XCTMetric, kotlinx-benchmark, Google Benchmark) |
security | Verifies authentication, authorization, input sanitization, or secrets handling | Tests for SQL injection, XSS, CSRF, unauthorized access, token validation, permission checks |
concurrency | Validates thread safety, parallelism, or async correctness | Uses Task.WhenAll / Parallel.ForEach / SemaphoreSlim (.NET); asyncio.gather / threading.Lock / multiprocessing (Python); Promise.all / worker threads (JS/TS); CompletableFuture / ExecutorService / synchronized (Java); go func / sync.WaitGroup / sync.Mutex / chan (Go); Mutex / Thread.new (Ruby); tokio::spawn / Arc<Mutex<_>> / crossbeam (Rust); DispatchQueue / actor (Swift); coroutineScope / Mutex (Kotlin); Start-Job / RunspacePool (PowerShell); std::thread / std::mutex (C++); reproduces race conditions |
resilience | Tests retry logic, timeouts, circuit breakers, or graceful degradation | Asserts behavior under transient failures, network drops, or service unavailability (e.g., Polly, tenacity, p-retry, resilience4j, hystrix, opossum, retry-go) |
destructive | Mutates shared or external state that is hard to roll back | Deletes records, drops resources, modifies global config -- useful for CI isolation decisions |
configuration | Verifies settings loading, defaults, environment behavior | Tests missing config keys, invalid values, environment variable fallbacks, options validation |
flaky | Known to intermittently fail (meta-tag for test health tracking) | Mark tests the team knows are unreliable; used to quarantine or prioritize stabilization |
A single test may have multiple traits (e.g., both negative and boundary). At minimum, every test should receive one of positive or negative.
Identify the codebase's language and test framework. Call the test-analysis-extensions skill and read the matching extension file. The extension file declares a tag-support capability for each framework:
auto-edit — framework has canonical tag syntax this skill can safely insert (.NET [TestCategory] / [Trait] / [Category] / [Property], pytest @pytest.mark.<name>, JUnit 5 @Tag("..."), TestNG groups = {"..."}, RSpec metadata it "..." , :tag => true, Pester -Tag '...', Kotest @Tags(...), Swift Testing @Tag(.tagName), Catch2 [tag], doctest * doctest::test_suite("tag") decorator).report-only — framework has no canonical, agreed-upon tag attribute; report tags in a Markdown table only and do not edit source (Go standard testing without build-tag conventions, Jest/Vitest without consistent describe-prefix convention, Rust without project-specific cfg conventions, XCTest without a test plan, GoogleTest without test-name prefix conventions, Mocha without describe-prefix conventions).convention-based — framework uses naming or file conventions for tagging (Go //go:build integration build tags, file-name suffixes like *_integration_test.go, GoogleTest INTEGRATION_* filter prefix). Only emit canonical edits when the user has confirmed the project convention; otherwise treat as report-only.Capture the capability before Step 4.
Check which tests already have trait attributes. Use the loaded language extension as the source of truth — examples:
| Framework | Existing Attribute | Example |
|---|---|---|
| MSTest | [TestCategory("...")] | [TestCategory("positive")] |
| xUnit | [Trait("Category", "...")] | [Trait("Category", "positive")] |
| NUnit | [Category("...")] | [Category("positive")] |
| TUnit | [Property("Category", "...")] | [Property("Category", "positive")] |
| JUnit 5 | @Tag("...") | @Tag("positive") |
| TestNG | @Test(groups = {"..."}) | @Test(groups = {"positive"}) |
| pytest | @pytest.mark.<name> | @pytest.mark.positive |
| RSpec | metadata after it | it "...", :positive do |
| Pester | -Tag '...' | It '...' -Tag 'positive' |
| Kotest | @Tags(...) | @Tags(Positive) |
| Swift Testing | @Tag(.<name>) | @Test(.tags(.positive)) |
| Catch2 | [tag] in name | TEST_CASE("...", "[positive]") |
| doctest | * doctest::test_suite("...") decorator | TEST_CASE("..." *doctest::test_suite("positive")) |
Record which tests already have tags to avoid duplication.
For each test method without traits, analyze:
Invalid, Fail, Error, Throw, Reject, BadInput, Null, None, Nil, Negative, raises_, _throws_, _returns_error suggest negativeAssert.ThrowsException / Assert.Throws / Should().Throw() / pytest.raises / expect(fn).toThrow / assertThrows / assert.Error(t, err) / expect { ... }.to raise_error / #[should_panic] / XCTAssertThrowsError / Should -Throw / EXPECT_THROW suggest negativenull / None / nil / undefined, "", 0, -1, int.MaxValue / sys.maxsize / Number.MAX_SAFE_INTEGER / math.MaxInt64 / i32::MAX, empty collections suggest boundarysmoke; external dependencies (file/db/net/env) suggest integrationregressionStopwatch, BenchmarkDotNet, elapsed-time checks; pytest-benchmark fixtures; benchmark.js; JMH @Benchmark; go test -bench; criterion.rs; XCTMetric; Google Benchmark; kotlinx-benchmark suggest performancecritical-pathsecurityconcurrencyresiliencedestructiveend-to-endconfigurationflakypositiveWhen in doubt between positive and negative, read the assertion: if it asserts success -> positive; if it asserts failure -> negative.
If the loaded language extension declares auto-edit for the framework, add the appropriate attribute to each test method. Place trait attributes adjacent to the existing test attribute. Examples:
MSTest:
[TestMethod]
[TestCategory("negative")]
[TestCategory("boundary")]
public void Parse_NullInput_ThrowsArgumentNullException() { ... }xUnit:
[Fact]
[Trait("Category", "positive")]
[Trait("Category", "critical-path")]
public void CreateOrder_ValidItems_ReturnsConfirmation() { ... }NUnit:
[Test]
[Category("regression")]
[Category("negative")]
public void Calculate_OverflowInput_ReturnsError() // Fix for #1234
{ ... }pytest:
@pytest.mark.negative
@pytest.mark.boundary
def test_parse_none_input_raises_value_error():
...JUnit 5:
@Test
@Tag("positive")
@Tag("critical-path")
void createOrder_validItems_returnsConfirmation() { ... }TestNG:
@Test(groups = {"negative", "boundary"})
public void parse_nullInput_throwsIllegalArgumentException() { ... }RSpec:
it "rejects null input", :negative, :boundary do
...
endPester:
It 'Rejects null input' -Tag 'negative','boundary' {
...
}Kotest:
@Tags(Negative, Boundary)
class ParserSpec : StringSpec({
"rejects null input" { ... }
})Swift Testing:
@Test(.tags(.negative, .boundary))
func parseNullInputThrows() throws { ... }Catch2:
TEST_CASE("Parse null input throws", "[negative][boundary]") { ... }If the loaded language extension declares report-only for the framework (Go standard testing, plain Jest/Vitest without convention, Rust without project-specific cfg, plain XCTest, plain GoogleTest, plain Mocha), do NOT modify source files. Instead emit a Markdown table mapping each test to its suggested tags, and recommend a project-wide convention the team can adopt (build tags, file suffix, describe-block prefix, GoogleTest filter prefix, test-plan grouping, etc.).
If the loaded language extension declares convention-based (e.g., Go //go:build integration, *_integration_test.go, GoogleTest INTEGRATION_* prefix), only emit canonical edits when the user has confirmed the project's convention. Otherwise treat as report-only.
After tagging, produce a summary table:
## Trait Distribution
| Trait | Count | % of Total |
|---------------|-------|------------|
| positive | 42 | 53.8% |
| negative | 22 | 28.2% |
| boundary | 8 | 10.3% |
| critical-path | 12 | 15.4% |
| smoke | 3 | 3.8% |
| regression | 5 | 6.4% |
| integration | 4 | 5.1% |
| end-to-end | 2 | 2.6% |
| performance | 1 | 1.3% |
| security | 3 | 3.8% |
| concurrency | 2 | 2.6% |
| resilience | 1 | 1.3% |
| destructive | 1 | 1.3% |
| configuration | 2 | 2.6% |
| flaky | 1 | 1.3% |
| **Total tests** | **78** | -- |
Note: Percentages exceed 100% because tests can have multiple traits.Include observations such as:
positive or negative at minimum) — in the report for report-only frameworks, or as an attribute for auto-edit frameworksauto-edit frameworks, the project still builds / tests still discover after changes (dotnet build / pytest --collect-only / mvn test-compile / go vet ./... / cargo check --tests / npm run test:list / Invoke-Pester -PassThru -Skip / equivalent)report-only frameworks, no source files were modifiedconvention-based frameworks, edits were applied ONLY when a project convention was confirmed| Pitfall | Solution |
|---|---|
| Guessing traits without reading the test body | Always read assertions and setup to classify accurately |
Tagging a test only as boundary without positive/negative | Every test should also be positive or negative -- boundary is additive |
| Using the wrong attribute syntax for the detected framework | Match the attribute style to the loaded language extension (don't put [TestCategory] in an xUnit project or @pytest.mark.x in a unittest test) |
| Duplicating an existing category attribute | Check for pre-existing traits in Step 2 before adding |
Over-tagging as critical-path | Reserve for tests on primary public entry points, not every helper |
| Editing Go / plain Jest / plain Rust / plain XCTest / plain GoogleTest source | These are report-only by default — emit a Markdown table instead. Only edit if the user confirms a project-wide convention (build tag, file suffix, describe-prefix, test-plan grouping). |
| Inventing tag prefixes for convention-based frameworks | Confirm the project's existing convention before adopting one — don't guess between _integration_test.go, //go:build integration, or IntegrationTest prefix |
| Missing language-specific concurrency / async primitives | Each language has its own primitives — read the loaded language extension and the Trait Taxonomy concurrency row before classifying as concurrency |
© microsoft, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Just SKILL.md in .agents/skills/test-tagging of microsoft/testfx.
Open the folder on GitHubat commit 44b9dcc
Test Tagging next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Test Tagging this skillmicrosoft/testfx | 1k | — | ~4.3k | Automated safety check: Pass | MIT | |
| TDD Guidealirezarezvani/claude-skills | 28k | — | ~3.4k | Automated safety check: Pass | MIT | |
| TDD GuideLeoYeAI/openclaw-master-skills | 2.2k | — | ~1.4k | Automated safety check: Pass | MIT | |
| TDD Guideborghei/Claude-Skills | 874 | — | ~1.7k | Automated safety check: Pass | MIT | |
| TDD GuideaAAaqwq/AGI-Super-Team | 105 | 2 repos | ~1.1k | Automated safety check: Pass | MIT | |
| MoAI TDD Workflowmodu-ai/moai-adk | 1.2k | — | ~3.1k | Automated safety check: Pass | Apache-2.0 |
alirezarezvani/claude-skills
Test-driven development skill for writing unit tests, generating test fixtures and mocks, analyzing coverage gaps, and guiding red-green-refactor workflows across Jest, Pytest, JUnit, Vitest, and…
LeoYeAI/openclaw-master-skills
Test-driven development skill for writing unit tests, generating test fixtures and mocks, analyzing coverage gaps, and guiding red-green-refactor workflows across Jest, Pytest, JUnit, Vitest, and…
borghei/Claude-Skills
Guide red-green-refactor TDD with test generation, coverage-gap analysis, and multi- framework support.
aAAaqwq/AGI-Super-Team
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modu-ai/moai-adk
Drives test-first development through the RED, GREEN, REFACTOR cycle, with a config switch that selects between TDD and a DDD workflow for existing code.
rohitg00/skillkit
Applies proven testing patterns — Arrange-Act-Assert (AAA), Given-When-Then, Test Data Builders, Object Mother, parameterized tests, fixtures, spies, and test doubles — to help write maintainable…
microsoft/testfx
Guide for organizing MSBuild infrastructure with Directory.Build.props, Directory.Build.targets, Directory.Packages.props, and Directory.Build.rsp.
microsoft/testfx
Analyze MSBuild binary logs to diagnose build failures. An agent skill from microsoft/testfx.
microsoft/testfx
Project-wide code coverage and CRAP (Change Risk Anti-Patterns) score analysis for .NET projects.
microsoft/testfx
Guide for optimizing MSBuild incremental builds. An agent skill from microsoft/testfx.
microsoft/testfx
Guide for modernizing and migrating MSBuild project files to SDK-style format.
microsoft/testfx
Catalog of MSBuild anti-patterns with detection rules and fix recipes.
Categories
Analyzes test suites in any language and tags each test with a standardized set of traits (positive, negative, critical-path, boundary, smoke, regression, integration, performance, security). Test Tagging is an agent skill from microsoft/testfx, published by the product's own GitHub organization. Analyzes test suites in any language and tags each test with a standardized set of traits (positive, negative, critical-path, boundary, smoke, regression, integration, performance, security).
Test Tagging fits situations like: the user wants to categorize; label tests with traits; writing new tests; migrating frameworks.
Run `npx skills add microsoft/testfx --skill test-tagging -a claude-code`. Or copy the skill folder (.agents/skills/test-tagging in microsoft/testfx) into .claude/skills/test-tagging in your project. Claude Code loads it when a task matches its description.
Run `npx skills add microsoft/testfx --skill test-tagging -a codex`. Or copy the skill folder (.agents/skills/test-tagging in microsoft/testfx) into .agents/skills/test-tagging in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add microsoft/testfx --skill test-tagging -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/test-tagging, .gemini/skills/test-tagging, .github/skills/test-tagging and .opencode/skills/test-tagging in your project.
Going by SKILL.md and its folder, Test Tagging needs the command-line tools its instructions call (go, dotnet, pytest, mvn, cargo and npm). Our summary lists: Python 3.
SKILL.md contains no URLs. Its commands use npm, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
Test Tagging is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
About 4.3k tokens (SKILL.md is roughly 17k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
Skills that share tags, products or a category with Test Tagging: TDD Guide (alirezarezvani/claude-skills, 28k stars), TDD Guide (LeoYeAI/openclaw-master-skills, 2.2k stars), TDD Guide (borghei/Claude-Skills, 874 stars) and TDD Guide (aAAaqwq/AGI-Super-Team, 105 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
microsoft (a GitHub organization, an official publisher) maintains it in microsoft/testfx, which has 1,047 GitHub stars. The repository holds 44 skills in this directory. The repository was last updated on October 7, 2026.
Source: microsoft/testfx on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.