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name: test-anti-patterns description: > Audit a test file or suite; produce a severity-ranked diagnostic report. ALWAYS USE for tests that verify nothing, missing/tautological assertions, swallowed/broad exceptions, flaky/order-dependent tests, duplication, or magic values. Polyglot. DO NOT USE for direct edits: writing-mstest-tests owns supplied MSTest assertions/attributes/lifecycle; code-testing-agent owns new tests. Exclude running tests, migration, assertion metrics (assertion-quality), raw .NET coverage collection (run-tests), non-.NET coverage collection/analysis (native tooling), project-wide .NET coverage/CRAP (coverage-analysis), named-target .NET CRAP (crap-score), behavioral/pseudo-mutation gaps (test-gap-analysis), test-mix/ happy-vs-error classification and trait distributions (test-tagging), or the testsmells.org catalog (test-smell-detection). license: MIT

Test Anti-Pattern Detection

Quick, pragmatic analysis of test code in any supported language for anti-patterns and quality issues that undermine test reliability, maintainability, and diagnostic value.

Language-specific guidance: Try test-analysis-extensions once. If it is unavailable, continue immediately with this skill's built-in framework rules; never block the audit on the helper.

When to Use

• User asks to review test quality or find test smells
• User wants to know why tests are flaky or unreliable
• User asks "are my tests good?" or "what's wrong with my tests?"
• User requests a test audit or test code review
• User wants diagnostic findings before deciding what to improve

When Not to Use

• User wants to write new tests from scratch (use code-testing-agent)
• User wants direct implementation fixes rather than a diagnostic review (use the relevant write/edit skill)
• User asks to fix swapped Assert.AreEqual argument order in MSTest (use writing-mstest-tests)
• User asks to convert MSTest DynamicData from IEnumerable<object[]> to ValueTuple (use writing-mstest-tests)
• User wants to run or execute tests (use run-tests for .NET)
• User wants to migrate between test frameworks or versions (use migration skills)
• User wants raw .NET coverage collection (use run-tests), non-.NET coverage collection or analysis (use native tooling), project-wide .NET coverage/CRAP metrics (use coverage-analysis), or named-target .NET CRAP (use crap-score)
• User asks whether tests would catch a bug or wants behavioral/pseudo-mutation gaps (use test-gap-analysis)
• User wants test-mix or happy-vs-error-path classification, standardized tagging, or trait/category distributions (use test-tagging)
• User wants a deep formal test smell audit with academic taxonomy and extended catalog (use test-smell-detection)

Inputs

| Input | Required | Description | |-------|----------|-------------| | Test scope | No | Test files, classes, directory, or project to analyze. Discover from the current workspace when omitted. | | Production code | No | The code under test, for context on what tests should verify | | Specific concern | No | A focused area like "flakiness" or "naming" to narrow the review |

Workflow

Step 1: Detect language and load extension

Resolve the named test path from the current workspace before asking for input. When no path is supplied, discover test files under the current directory using the repository manifests and conventional test markers. The skill context's Base directory is documentation storage, not the user's workspace; never resolve target files relative to it.

If one reader says a path is missing but a workspace glob/search finds it, normalize that exact path and retry. Use a shell text reader (sed/cat on Unix, Get-Content on PowerShell) only for a confirmed reader availability, transport, or path-normalization failure and only after verifying the canonical path remains inside the current workspace. Stop on content-exclusion, permission/policy, workspace-boundary, or unknown failures. Audit any discovered file that a permitted reader can access; never ask the user to paste it. If every permitted reader fails, report the exact blocker without bypassing security boundaries.

Identify the language and framework. Try the matching test-analysis-extensions guidance once; if unavailable, use the catalog below.

Step 2: Gather the test code

Inventory the resolved scope before reading bodies. For one file or class, read that scope directly. For a project or suite, discover test files once, batch independent reads where tools allow, and stop when every discovered test and class-level fixture has a ledger disposition.

Use extension discovery markers when loaded; otherwise use the built-in markers in this skill (attributes such as [TestClass]/[Fact]/[Test], test_*.py, *.test.*, *_test.go, *_spec.rb, #[test], *.Tests.ps1, TEST(...), and TEST_CASE(...)).

Do not read unrelated production code wholesale. Open the production symbol corresponding to every suspicious test needed to decide whether an assertion, transformation, identity contract, or adjacent gap is real. For a systematic facade/surface-area pattern, every invoked member is relevant: read the entire small production type or inspect each invoked member, then map each weak test to the exact observable result, exception, state change, or boundary it should verify.

Step 3: Scan for anti-patterns

Check each test file against the anti-pattern catalog below. Report findings grouped by severity. Use extension mappings when loaded; otherwise use the cross-framework examples in the catalog.

Before drafting the report, make a private completeness ledger with one row for every test method and every class-level fixture/resource. Record its oracle (or absence), exception handling, state/time dependencies, concurrency safety, precondition/assertion order, and disposition. Do not publish until every row is either attached to a finding or explicitly judged sound. In particular:

• actual != oldValue is a weak mutation oracle: it accepts every wrong new value. Require the exact expected value.
• Include unused or undisposed class-level resources; method-only scans miss fields such as a static HttpClient.
• Treat an unsynchronized static/global collection as both order-coupled and parallel-unsafe when tests read and write it. Also flag dereferencing a nullable result before the assertion intended to prove it non-null.
• When production code is supplied, note obvious untested contracts adjacent to a finding, but do not perform exhaustive branch or mutation analysis. Route that broader question to test-gap-analysis.

Critical -- Tests that give false confidence

| Anti-Pattern | What to Look For | |---|---| | No assertions | Test methods that execute code but never assert anything. A passing test without assertions proves nothing. In .NET look for missing Assert.*; in pytest a function with no assert and no pytest.raises; in Jest no expect(...); in JUnit no assert*/assertThat; in Go a test that never calls t.Error*, t.Fatal*, or testify; in RSpec a block with no expect; in Pester no Should. Mock-call verifications (verify(mock), expect(mock).toHaveBeenCalled, Should -Invoke) are real assertions. | | Missing await on async assertions (JS/TS, .NET, Python, Kotlin, Swift) | expect(promise).resolves.toBe(x) without await/return, pytest-asyncio test with un-awaited coroutine, async Task xUnit test calling Assert.ThrowsAsync without await, Kotest suspending test without runTest, Swift Testing async test without await. These tests silently pass even when the underlying assertion would have failed. | | Coverage touching | Test class that methodically calls every public member on a type — often in alphabetical or declaration order — without asserting meaningful outcomes. Each test typically does var result = sut.MethodName(...) (or result = sut.method_name(...), sut.methodName(), sut.MethodName(t)) with no assertion, or only a trivial null/None/nil check. The intent is to inflate code-coverage metrics rather than verify behavior. Distinct from a single assertion-free test: the pattern is systematic coverage of the surface area with no real verification. | | Self-referential assertion | The expected value is computed from the same actual value, such as Assert.AreEqual(dto.Name, dto.Name), Assert.AreEqual(result, result), or equivalents. Do not apply this label merely because a valid identity, clone, serialization, or round-trip contract compares output with input: those assertions can fail. Instead check whether the input exercises a transformation and whether independently known representation, field, reference-identity, or invalid-input assertions are missing. | | Swallowed exceptions | try { ... } catch { }, catch (Exception) without rethrowing or asserting (.NET); bare except: or except Exception: with pass (Python); try { ... } catch (e) {} (JS/TS/Java); defer recover() without re-panic and no assertion (Go); rescue StandardError with no assertion (Ruby); Result::unwrap_or(...) swallowing errors in a test (Rust); empty catch block (Kotlin/Swift). | | Assert in catch block only | try { Act(); } catch (Exception ex) { Assert.Fail(ex.Message); } (and equivalents in other languages) -- use Assert.ThrowsException / pytest.raises / expect(fn).toThrow / assertThrows / assert.Error(t, err) / #[should_panic] / Should -Throw / EXPECT_THROW instead. The test passes when no exception is thrown even if the result is wrong. | | Always-true assertions | Assert.IsTrue(true), Assert.AreEqual(x, x), assert True, expect(true).toBe(true), assert.True(t, true), assert!(true), or conditions that can never fail. | | Commented-out assertions | Assertions that were disabled but the test still runs, giving the illusion of coverage. |

High -- Tests likely to cause pain

| Anti-Pattern | What to Look For | |---|---| | Flakiness indicators | Wall-clock sleeps/waits used for synchronization: Thread.Sleep / Task.Delay (.NET), time.sleep (Python), setTimeout / await new Promise(r => setTimeout(...)) (JS/TS), Thread.sleep (Java/Kotlin), time.Sleep (Go), sleep (Ruby/Bash), std::thread::sleep (Rust), Start-Sleep (Pester), std::this_thread::sleep_for (C++). Wall-clock reads without abstraction: DateTime.Now/UtcNow, datetime.now()/datetime.utcnow(), Date.now() / new Date(), System.currentTimeMillis(), time.Now(), Time.now, Instant::now(), Date()/Date.now, Get-Date, std::chrono::system_clock::now. Unseeded randomness: new Random(), random.random()/random.randint(), Math.random(), new Random() (Java/Kotlin), rand.Int() without seed, rand (Ruby), rand::random() (Rust). Environment-dependent paths (hard-coded C:\..., /tmp/..., network hosts). | | Test ordering dependency | Static/global mutable state modified across tests; setup that doesn't fully reset state ([TestInitialize], setUp, beforeEach, before(:each), BeforeEach, t.Cleanup); tests that fail when run individually but pass in suite (or vice versa). Examples per language: static fields (.NET/Java), module-level globals (Python), top-level let/const in test file (JS/TS), var package globals (Go), class variables (Ruby), static mut/lazy_static!/OnceCell (Rust), $script: variables (PowerShell). | | Over-mocking | More mock setup lines than actual test logic. Verifying exact call sequences on mocks rather than outcomes. Mocking types the test owns. Per language: Moq/NSubstitute/FakeItEasy (.NET), unittest.mock / pytest-mock (Python), Jest auto-mocks / Sinon (JS/TS), Mockito/PowerMock (Java), gomock/testify mock (Go), RSpec mocks/mocha (Ruby), mockall (Rust), MockK (Kotlin), Mock cmdlet (Pester), gmock (C++). For a deep mock audit in .NET, use