| name | test-tagging |
| description | Classifies existing tests by standard traits and reports their distribution. MUST USE to categorize/tag/label tests, compare happy vs error paths, audit the test mix, or describe coverage shape by test type. Read bodies when names mislead. Apply canonical attributes; otherwise report only. DO NOT USE for test-quality audits, executed coverage or CRAP, behavioral gaps, writing tests, or migration.
|
| license | MIT |
Test Trait Tagging
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-extensions skill 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.
When to Use
- Auditing a test project to understand the mix of test types
- Adding trait attributes to untagged tests
- Generating a summary report of trait distribution across a test suite
- Reviewing whether critical paths have sufficient coverage
When Not to Use
- Writing new tests from scratch (use
code-testing-agent for any language, or writing-mstest-tests for MSTest)
- Running or filtering tests (use
run-tests for .NET; equivalent native runners elsewhere)
- Migrating between test frameworks
- General quality, smell, flakiness, or assertion audits (use
test-anti-patterns or the matching analysis skill)
- Diagnostic .NET executed line/branch/Cobertura interpretation or project-wide CRAP risk (use
coverage-analysis); raw coverage collection (use run-tests for .NET, native tooling otherwise)
- CRAP analysis for a named method, class, or file (use
crap-score)
- Behavioral gaps where a test would survive broken production logic (use
test-gap-analysis)
Inputs
| Input | Required | Description |
|---|
| Test project or files | Yes | Path to the test project, folder, or specific test files to analyze |
| Scope | No | tag (apply canonical attributes, or a confirmed project convention), audit (report only), or both (default: both). Frameworks declared report-only always emit a report; convention-based frameworks edit only after the user confirms the convention. |
| Framework | No | Auto-detected. Override when detection fails. |
Trait Taxonomy
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 |
A single test may have multiple traits (e.g., both negative and boundary). At minimum, every test should receive one of positive or negative.
Workflow
Step 1: Detect the language, framework, and tagging capability
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.
Step 2: Scan existing traits
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.
Step 3: Classify each test method
Build one canonical inventory containing each discovered test exactly once.
Record the test identifier, behavioral classification, and traits in that
inventory; use the same rows for source edits, per-test reporting, totals, and
distribution counts. Do not hand-count a separate denominator. Before
publishing, reconcile the reported total with the number of inventory rows and
verify that every row contributes to each displayed trait count.
For each test method without traits, analyze:
- Method name -- names containing
Invalid, Fail, Error, Throw, Reject, BadInput, Null, None, Nil, Negative, raises_, _throws_, _returns_error suggest negative
- Assertion type --
Assert.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 negative
- Input values --
null / None / nil / undefined, "", 0, -1, int.MaxValue / sys.maxsize / Number.MAX_SAFE_INTEGER / math.MaxInt64 / i32::MAX, empty collections suggest boundary
- Setup complexity -- minimal setup with basic assertions suggests
smoke; external dependencies (file/db/net/env) suggest integration
- Comments and names -- references to issue numbers or "regression" / "bug" / "fix for #..." suggest
regression
- Timing assertions --
Stopwatch, BenchmarkDotNet, elapsed-time checks; pytest-benchmark fixtures; benchmark.js; JMH @Benchmark; go test -bench; criterion.rs; XCTMetric; Google Benchmark; kotlinx-benchmark suggest performance
- Feature centrality -- tests on primary public API entry points or critical user workflows suggest
critical-path
When in doubt between positive and negative, read the assertion: if it asserts success -> positive; if it asserts failure -> negative.
Step 4: Apply trait attributes (or report only)
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()
{ ... }
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
...
end
Pester:
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 concise mapping from each test to its suggested tags. Recommend a project-wide convention only when the user asks how to persist or filter those tags; an analysis-only request should report and stop.
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.
Step 5: Generate trait summary
After tagging, produce a summary table. Include only traits with a non-zero
count unless the user asks for the full taxonomy; zero-filled rows obscure the
suite's actual shape. For a small report-only suite, keep the per-test mapping
and non-zero distribution together rather than expanding into a dashboard.
## Trait Distribution
| Trait | Count | % of Total |
|---------------|-------|------------|
| positive | 50 | 64.1% |
| negative | 28 | 35.9% |
| boundary | 8 | 10.3% |
| critical-path | 12 | 15.4% |
| **Total tests** | **78** | -- |
Note: Percentages exceed 100% because tests can have multiple traits.
Include observations such as:
- Ratio of positive to negative tests
- Whether critical-path tests exist for key public APIs
- Any tests that could not be confidently classified (list them for manual review)
Validation
Common Pitfalls
| 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 |