[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)

🤖 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 Test Improver workflow. · 1.7K AIC · ⌖ 23.7 AIC · ⊞ 58K · [◷]( · ◷)

Add this agentic workflows to your repo

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/test-improver.md@main

[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