Migrate Test Project to Native Microsoft.Testing.Platform

[ptr727]

Why

Same regression as #447, on main this time (per .github/dependabot.yml, main and develop are kept current independently). The .NET 10 SDK dropped the VSTest bridge dotnet test relied on, so dotnet test failed outright: Testing with VSTest target is no longer supported by Microsoft.Testing.Platform on .NET 10 SDK and later. This is what was blocking #443 and #444 (both currently fail on the Run unit tests job).

What

Identical fix to #447, cherry-picked (the relevant files were byte-identical between main and develop before this PR):

• Opt UtilitiesTests into native Microsoft.Testing.Platform (MTP) via global.json's test.runner setting plus UseMicrosoftTestingPlatformRunner/OutputType=Exe.
• Swap coverlet.collector (VSTest-only) for Microsoft.Testing.Extensions.CodeCoverage (native MTP coverage), marked test-only via PrivateAssets.
• Bump Microsoft.NET.Test.Sdk/xunit.v3/xunit.analyzers/xunit.runner.visualstudio to versions with a compatible MTP runtime.
• Update the validate workflow's dotnet test invocation (--coverage instead of --collect, with an explicit --coverage-output filename codecov-action can discover).
• Fix three ExtensionsTests.cs null-argument tests missing a null-forgiving operator.
• global.json in CRLF (this repo's .editorconfig convention) and added to Solution Items.

Verification

Already went through #447's full review loop (local adversarial review, Copilot, CodeRabbit, all findings fixed) on identical content. Re-verified independently on this branch: dotnet build (0 warnings/errors), dotnet test --coverage --coverage-output-format cobertura --coverage-output coverage.cobertura.xml --results-directory ./coverage (183/183 passed), dotnet csharpier check ., dotnet format style --verify-no-changes, and editorconfig-checker on global.json all clean.

Summary by CodeRabbit

• Tests

  • Updated automated test execution with a modern test runner for more reliable validation.
  • Added improved code coverage collection and Cobertura report generation for clearer quality metrics.
  • Updated testing tools and frameworks to newer versions.
  • Preserved existing compression test behavior while improving nullable-value handling during test execution.

• Chores

  • Added centralized configuration for consistent test tooling across the solution.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 96a4b000-aa54-41c9-ad6a-f67d6b73d56d

📥 Commits

Reviewing files that changed from the base of the PR and between 2481f65 and 99af69f.

📒 Files selected for processing (6)

• .github/workflows/validate-task.yml
• Directory.Packages.props
• Utilities.slnx
• UtilitiesTests/ExtensionsTests.cs
• UtilitiesTests/UtilitiesTests.csproj
• global.json

Included review availability: Your plan provides up to 10 included reviews per hour; 1 remains after this review.

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📝 Walkthrough

Walkthrough

The test suite now runs through Microsoft Testing Platform. Coverage uses Microsoft.Testing.Extensions.CodeCoverage and produces an explicit Cobertura report for Codecov. Test package versions and nullable test calls were updated.

Changes

Microsoft Testing Platform migration

Layer / File(s)	Summary
Test runner configuration global.json, Utilities.slnx, Directory.Packages.props, UtilitiesTests/UtilitiesTests.csproj, UtilitiesTests/ExtensionsTests.cs	The repository selects Microsoft Testing Platform, updates test packages, configures the test project as an executable, and suppresses nullable warnings in null-input tests.
Coverage pipeline .github/workflows/validate-task.yml, UtilitiesTests/UtilitiesTests.csproj	The project and workflow replace Coverlet with Microsoft Testing Platform coverage and generate ./coverage/coverage.cobertura.xml for Codecov.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk:⚪ Minimal · up to 99af6

This PR updates the test project and validation workflow for native Microsoft.Testing.Platform coverage and corrects three test arguments. No actionable merge-blocking risk remains beyond normal checks and review.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 1 files. (5 skipped: 5 …	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: migrating the test project to native Microsoft.Testing.Platform support.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 1 files. (5 skipped: 5 unsupported.)

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/dotnet-testing-platform-main

---

_{Comment @coderabbitai help to get the list of available commands.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.24%. Comparing base (2481f65) to head (99af69f).

Additional details and impacted files

@@ Coverage Diff @@## main #448 +/- ##
==========================================
+ Coverage 66.89% 67.24% +0.34% 
==========================================
Files 13 13 Lines 1160 1154 -6 Branches 108 106 -2 ==========================================
Hits 776 776 Misses 338 338 + Partials 46 40 -6 

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📢 Have feedback on the report? Share it here.

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• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[qodo-code-review]

PR Summary by Qodo

Migrate UtilitiesTests to Native Microsoft.Testing.Platform

🐞 Bug fix⚙️ Configuration changes🕐 20-40 Minutes

AI Description

• Migrates UtilitiesTests from the obsolete VSTest bridge to native Microsoft.Testing.Platform.
• Replaces VSTest coverage collection while preserving Codecov discovery in .NET 10 CI.
• Upgrades compatible test dependencies and resolves nullable warnings in null-input tests.

Diagram

graph TD
G["Runner config"] -->|selects MTP| D["dotnet test"] -->|launches| T["UtilitiesTests"] -->|loads| C["Coverage extension"] -->|writes| F["Cobertura report"] -->|uploads| U["Codecov"]
P["Test packages"] -->|provide runtime| T

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High-Level Assessment

The following are alternative approaches to this PR:

1. Remain on VSTest with an older SDK

• ➕ Minimizes immediate project and coverage configuration changes.
• ➕ Retains the existing coverlet.collector workflow.
• ➖ Conflicts with the repository's .NET 10 target.
• ➖ Defers an unavoidable migration and blocks dependency updates.

2. Use Coverlet MSBuild integration

• ➕ Could preserve Coverlet-generated Cobertura coverage without VSTest collection.
• ➕ Supports command-line coverage through MSBuild properties.
• ➖ Adds MSBuild-specific invocation complexity.
• ➖ Diverges from the native MTP coverage extension and its standard CLI flags.

Recommendation: Keep the native Microsoft.Testing.Platform migration. It aligns the test project with .NET 10, uses an MTP-native coverage provider, and explicitly names the report so the existing Codecov step remains reliable.

Files changed (6) +31 / -12

Bug fix (2) +17 / -4

validate-task.ymlRun native MTP tests with discoverable coverage output+7/-2

Run native MTP tests with discoverable coverage output

• Replaces the VSTest collector invocation with Microsoft.Testing.Platform coverage flags. The workflow explicitly names the Cobertura report so codecov-action can discover and upload it.

.github/workflows/validate-task.yml

UtilitiesTests.csprojConfigure UtilitiesTests as a native MTP executable+10/-2

Configure UtilitiesTests as a native MTP executable

• Makes the test project executable, enables the Microsoft.Testing.Platform runner, and references the native coverage extension with compile-time registration assets kept private.

UtilitiesTests/UtilitiesTests.csproj

Tests (1) +3 / -3

ExtensionsTests.csSuppress expected nullable dereference warnings in null tests+3/-3

Suppress expected nullable dereference warnings in null tests

• Adds null-forgiving operators to three deliberate null receiver calls, allowing warnings-as-errors builds while retaining the exception assertions.

UtilitiesTests/ExtensionsTests.cs

Other (3) +11 / -5

Directory.Packages.propsUpgrade the MTP-compatible test dependency stack+5/-5

Upgrade the MTP-compatible test dependency stack

• Replaces coverlet.collector with Microsoft.Testing.Extensions.CodeCoverage and upgrades Microsoft.NET.Test.Sdk plus the xUnit package family to compatible versions.

Directory.Packages.props

Utilities.slnxExpose global test configuration in solution items+1/-0

Expose global test configuration in solution items

• Adds global.json to Solution Items so the repository-level test runner configuration is visible from the solution.

Utilities.slnx

global.jsonSelect Microsoft.Testing.Platform as the repository test runner+5/-0

Select Microsoft.Testing.Platform as the repository test runner

• Adds repository-wide dotnet test configuration that opts into the native Microsoft.Testing.Platform runner.

global.json

[qodo-code-review]

Code Review by Qodo

🐞 Bugs (0)📘 Rule violations (0)📜 Skill insights (0)

1. Coverage comments are narrow-wrapped✗ Dismissed📘 Rule violation⚙ Maintainability

Description

The added coverage explanation is formatted as four short prose lines even though the workflow
allows approximately 120 columns. This violates the required wide-line formatting for multi-line
comments.

Code

.github/workflows/validate-task.yml[R27-30]

+ # dotnet test runs on native Microsoft.Testing.Platform (global.json test.runner); --coverage+ # drives Microsoft.Testing.Extensions.CodeCoverage to emit Cobertura XML into ./coverage/.+ # --coverage-output names the file explicitly: the default is a GUID basename that+ # codecov-action's file finder does not match, so the upload step would silently find nothing.

Evidence

PR Compliance ID 2826618 requires modified multi-line prose comments to use wide lines where the
surrounding file permits it. The added workflow comment uses several substantially shorter prose
lines in a file whose existing comments target a wider line length.

Rule 2826618: Format multi-line comments as wide lines or concise bullets, not narrow prose
.github/workflows/validate-task.yml[27-30]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution
## Issue description
The added coverage explanation is narrow-wrapped across several prose comment lines instead of using lines near the repository's 120-column width.
## Issue Context
Preserve the explanation and rationale, but reflow each logical paragraph into wider comment lines.
## Fix Focus Areas
- .github/workflows/validate-task.yml[27-30]

ⓘ Copy this prompt and use it to remediate the issue with your preferred AI generation tools

---

2. Project comments are narrow-wrapped✗ Dismissed📘 Rule violation⚙ Maintainability

Description

The new project-file rationale is split into multiple short prose lines despite sufficient room to
format it near the repository's 120-column width. The same narrow wrapping is repeated in the added
coverage-provider comments.

Code

UtilitiesTests/UtilitiesTests.csproj[R5-6]

+ <!-- .NET 10 SDK dropped the VSTest bridge for dotnet test; run xunit.v3 through native+ Microsoft.Testing.Platform instead (paired with global.json's "test.runner" setting). -->

Evidence

PR Compliance ID 2826618 requires modified multi-line comments to avoid short prose wrapping when
the file has room for approximately 120-character lines. The new MTP and coverage comments are each
wrapped into short lines without a structural or tooling constraint requiring those breaks.

Rule 2826618: Format multi-line comments as wide lines or concise bullets, not narrow prose
UtilitiesTests/UtilitiesTests.csproj[5-6]
UtilitiesTests/UtilitiesTests.csproj[19-22]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution
## Issue description
The newly added XML comments are narrow-wrapped prose rather than wide lines near the configured code width.
## Issue Context
Keep the non-obvious MTP rationale, but reflow the logical comment paragraphs without changing their meaning.
## Fix Focus Areas
- UtilitiesTests/UtilitiesTests.csproj[5-6]
- UtilitiesTests/UtilitiesTests.csproj[19-22]

ⓘ Copy this prompt and use it to remediate the issue with your preferred AI generation tools

---

Context sources

✅ Compliance rules (platform): 30 rules

✅ Web pages:

🌐 Microsoft.Testing.Platform (MTP) code coverage - .NET | Microsoft Learn

🌐 microsoft-testing-platform-cli-options

🌐 Microsoft.Testing.Platform (MTP) test reports - .NET | Microsoft Learn

+9 more

Review mode: ⚖️ Balanced: This changes test execution and coverage tooling across project, package, CI, and global configuration; it has meaningful behavioral and workflow risk, but not enough independent logic density to justify extended review.

Tip of the day

💡 Did you know, you can group findings by type and pick your Finding display, from Minimal to Full

More tips ↗ | Customize Qodo ↗ | Qodo docs ↗

[ptr727]

Re Qodo's two "narrow-wrapped comments" findings (UtilitiesTests/UtilitiesTests.csproj:5-6, 19-22; .github/workflows/validate-task.yml:30): declining.

This repo's comment convention (fleet comment-and-doc-style, referenced from AGENTS.md's comments philosophy pointer) is one sentence per line, never wrapped prose: "Structured, not prose: one sentence per line, never wrapped across lines, never a multi-sentence run-on." Reflowing these comments to wide ~120-column prose lines per Qodo's rule 2826618 would go against that convention, not toward it. Keeping the comments as short, one-sentence lines.

[Copilot]

🟡 Changes recommended

The workflow writes --coverage-output to the repo root while Codecov is configured to only scan ./coverage, which can cause coverage uploads to be skipped.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR migrates the UtilitiesTests project and CI test execution to native Microsoft.Testing.Platform so dotnet test continues to work under the .NET 10 SDK (which removed the VSTest bridge).

Changes:

• Opt UtilitiesTests into native MTP (global.jsontest.runner, plus OutputType=Exe and UseMicrosoftTestingPlatformRunner=true).
• Replace VSTest-only coverlet.collector with Microsoft.Testing.Extensions.CodeCoverage and update the validate workflow to use dotnet test --coverage.
• Update test/tooling package versions and fix nullable warnings in null-argument tests.

File summaries

File	Description
UtilitiesTests/UtilitiesTests.csproj	Switch test project to MTP runner and adopt MTP-native coverage extension.
UtilitiesTests/ExtensionsTests.cs	Add null-forgiving operator in null-argument tests to satisfy nullable analysis.
Utilities.slnx	Add global.json to Solution Items.
global.json	Configure dotnet test to use Microsoft.Testing.Platform via test.runner.
Directory.Packages.props	Remove coverlet version and bump/add MTP-compatible test/coverage package versions.
.github/workflows/validate-task.yml	Update CI test invocation to MTP --coverage flow and configure coverage output naming.

Review details

• Files reviewed: 6/6 changed files
• Comments generated: 1
• Review effort level: Lite

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