[test-improver] test: add edge case tests for UnusedParameterSuppressor (MSTEST0047)

[Evangelink]

Goal and Rationale

UnusedParameterSuppressor (MSTEST0047) suppresses IDE0060 ("Remove unused parameter") when both of these hold:

1. The parameter type is TestContext
2. The containing method has [AssemblyInitialize], [ClassInitialize], [GlobalTestInitialize], or [GlobalTestCleanup]

The existing tests verified the positive cases (suppressed) and two negative cases (regular method / non-TestContext in TestMethod). However, the exact boundary conditions — one condition true but not the other — were untested.

Approach

Added two new test methods to UnusedParameterSuppressorTests.cs:

Test	Scenario	Expected
TestMethodWithUnusedTestContext_DiagnosticIsNotSuppressed	[TestMethod] with unused TestContext parameter	Not suppressed — [TestMethod] is not in the fixture-attribute list
AssemblyInitializeWithUnusedNonTestContextParameter_DiagnosticIsNotSuppressed	[AssemblyInitialize] with unused string parameter	Not suppressed — only TestContext parameters are eligible

Each test runs twice: once without the suppressor (to confirm the diagnostic fires), and once with the suppressor (to confirm it is not suppressed).

Coverage Impact

These tests target the two independent guard conditions in UnusedParameterSuppressor.ReportSuppressions, ensuring the parameter-type check and the attribute check are each independently exercised with a failing case.

Trade-offs

Minimal — tests follow the existing pattern in the file and add no complexity.

Reproducibility

.dotnet/dotnet test test/UnitTests/MSTest.Analyzers.UnitTests/MSTest.Analyzers.UnitTests.csproj \
  -f net8.0 --no-build -c Debug \
  --filter "FullyQualifiedName~UnusedParameterSuppressorTests"

Test Status

Build: ✅ succeeded (0 warnings, 0 errors)
MSTest.Analyzers.UnitTests (UnusedParameterSuppressorTests): ✅ 8 passed, 0 failed (was 6)

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[Copilot]

Pull request overview

Adds missing boundary-condition coverage for the UnusedParameterSuppressor (MSTEST0047) tests in the MSTest analyzers unit test suite, ensuring the suppressor only applies when both the parameter is TestContext and the containing method is one of the supported fixture lifecycle methods.

Changes:

• Added a negative test verifying [TestMethod] + unused TestContext is not suppressed.
• Added a negative test verifying [AssemblyInitialize] + unused non-TestContext parameter is not suppressed.

Show a summary per file

File	Description
test/UnitTests/MSTest.Analyzers.UnitTests/UnusedParameterSuppressorTests.cs	Adds two edge-case tests to independently exercise the suppressor’s attribute guard and parameter-type guard.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0

[Evangelink]

🧪 Test quality grade — PR #9301

Δ	Test	Grade	Band	Notes
new	UnusedParameterSuppressorTests. AssemblyInitializeWithUnusedNonTestContextParameter_ DiagnosticIsNotSuppressed	B	80–89	Strong diagnostic assertions (WithLocation, WithArguments, WithIsSuppressed); body is slightly long (~44 lines) due to embedded code string and idiomatic dual-run pattern.
new	UnusedParameterSuppressorTests. TestMethodWithUnusedTestContext_ DiagnosticIsNotSuppressed	B	80–89	Precise assertions verify diagnostic presence, location, argument name, and suppression state; mildly long (~44 lines) due to multi-line string literal and dual suppressor/non-suppressor verification runs.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 183.3 AIC · ⌖ 13 AIC · ⊞ 43.6K · [◷]( · ◷)

[Evangelink]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

✅ 22/22 dimensions clean — no findings.

---

Scope: single test file (test/UnitTests/MSTest.Analyzers.UnitTests/UnusedParameterSuppressorTests.cs); no production code changed.

Reviewed dimensions: Algorithmic Correctness · Threading & Concurrency · Security · Public API Compatibility · Performance · Cross-TFM · Resource Management · Defensive Coding · Localization · Test Isolation · Assertion Quality · Flakiness · Test Completeness · Data-Driven Coverage · Code Structure · Naming · Documentation · Analyzer Quality · IPC Wire · Build Infrastructure · Scope Discipline · PowerShell Hygiene

Notes:

• Both new tests correctly model the two independent guard conditions of UnusedParameterSuppressor: (1) the parameter type must be TestContext, and (2) the containing method must carry one of the four fixture attributes. TestMethodWithUnusedTestContext_DiagnosticIsNotSuppressed exercises condition-1-true / condition-2-false; AssemblyInitializeWithUnusedNonTestContextParameter_DiagnosticIsNotSuppressed exercises condition-1-false / condition-2-true. Both complement the four existing positive tests and the two pre-existing negative tests without any overlap.
• Each test correctly runs two phases — without the suppressor (baseline) and with the suppressor — and asserts WithIsSuppressed(false) in both, consistent with the AssemblyInitialize/ClassInitialize established pattern in the file.
• Test names follow the <Scenario>_<Expected> convention used throughout the file. Comments explain why the diagnostic is not suppressed, not just what the test does — good practice.
• No shared mutable state, no timing dependencies, no file-system access, no assertion library violations (MSTest Assert family is the correct choice for this project per BannedSymbols.txt).