Fixes #4787. Upgrade all nuget packages including the obsolete xunit v2

.claude/rules/testing-patterns.md

@@ -7,11 +7,8 @@
 - **Never decrease code coverage** - PRs must maintain or increase coverage
 - Target: **70%+ coverage** for new code
 - Coverage collection:
-  - Centralized in `TestResults/` directory at repository root
-  - Collected only on Linux (ubuntu-latest) runners in CI for performance
-  - Windows and macOS runners skip coverage collection to reduce execution time
-  - Coverage reports uploaded to Codecov automatically from Linux runner
-  - CI monitors coverage on each PR
+  - Temporarily disabled in CI during xUnit v3 / MTP migration
+  - Will be re-enabled once an MTP-compatible coverage solution is integrated
 
 ## Test Patterns
 
@@ -47,11 +44,11 @@
 - ~10 min timeout
 - Uses `Application.Init` and static state
 - Cannot run in parallel
-- Includes `--blame` flags for crash diagnostics
+- Includes `--diagnostic` flag for logging
 
 **Command:**
 ```bash
-dotnet test Tests/UnitTests --no-build --verbosity normal
+dotnet test --project Tests/UnitTests --no-build --verbosity normal
 ```
 
 ### 2. Parallel Tests (`Tests/UnitTestsParallelizable/`) - **PREFERRED**
@@ -67,7 +64,7 @@ dotnet test Tests/UnitTests --no-build --verbosity normal
 
 **Command:**
 ```bash
-dotnet test Tests/UnitTestsParallelizable --no-build --verbosity normal
+dotnet test --project Tests/UnitTestsParallelizable --no-build --verbosity normal
 ```
 
 ### 3. Integration Tests (`Tests/IntegrationTests/`)
@@ -78,13 +75,13 @@ dotnet test Tests/UnitTestsParallelizable --no-build --verbosity normal
 
 **Command:**
 ```bash
-dotnet test Tests/IntegrationTests --no-build --verbosity normal
+dotnet test --project Tests/IntegrationTests --no-build --verbosity normal
 ```
 
 ## Test Configuration Files
 
 - `xunit.runner.json` - xUnit configuration
-- `coverlet.runsettings` - Coverage settings (OpenCover format)
+- `coverlet.runsettings` - Coverage settings (currently unused, pending MTP integration)
 
 ## Example Test Pattern
 

.claude/tasks/clean-code-review.md

@@ -50,9 +50,9 @@ Run these for each commit:
 
 ```bash
 dotnet build --no-restore
-dotnet test Tests/IntegrationTests --no-build
-dotnet test Tests/UnitTests --no-build
-dotnet test Tests/UnitTestsParallelizable --no-build
+dotnet test --project Tests/IntegrationTests --no-build
+dotnet test --project Tests/UnitTests --no-build
+dotnet test --project Tests/UnitTestsParallelizable --no-build
 ```
 
 ## Terminal.Gui Specific Requirements

.claude/workflows/build-test-workflow.md

@@ -47,19 +47,19 @@ dotnet build --configuration Release --no-restore
 **Time:** ~10 min timeout
 
 ```bash
-dotnet test Tests/UnitTests --no-build --verbosity normal
+dotnet test --project Tests/UnitTests --no-build --verbosity normal
 ```
 
 - Uses `Application.Init` and static state
 - Cannot run in parallel
-- Includes `--blame` flags for crash diagnostics
+- Includes `--diagnostic` flag for logging
 
 ### Run Parallel Tests (Preferred)
 
 **Time:** ~10 min timeout
 
 ```bash
-dotnet test Tests/UnitTestsParallelizable --no-build --verbosity normal
+dotnet test --project Tests/UnitTestsParallelizable --no-build --verbosity normal
 ```
 
 - No dependencies on static state
@@ -69,13 +69,13 @@ dotnet test Tests/UnitTestsParallelizable --no-build --verbosity normal
 ### Run Integration Tests
 
 ```bash
-dotnet test Tests/IntegrationTests --no-build --verbosity normal
+dotnet test --project Tests/IntegrationTests --no-build --verbosity normal
 ```
 
 ### Run All Tests
 
 ```bash
-dotnet test --no-build --verbosity normal
+dotnet test --project Tests/UnitTests --no-build --verbosity normal && dotnet test --project Tests/UnitTestsParallelizable --no-build --verbosity normal
 ```
 
 ## Common Build Issues
@@ -94,7 +94,7 @@ dotnet restore ./Examples/SelfContained/SelfContained.csproj -f
 **For clean builds, always run in this order:**
 
 ```bash
-dotnet restore && dotnet build --no-restore && dotnet test --no-build
+dotnet restore && dotnet build --no-restore && dotnet test --project Tests/UnitTests --no-build && dotnet test --project Tests/UnitTestsParallelizable --no-build
 ```
 
 This ensures:

.claude/workflows/pr-workflow.md

@@ -27,7 +27,7 @@ Before submitting a PR, ensure:
 
 - [ ] **Build passes** locally: `dotnet build --no-restore`
 
-- [ ] **Tests pass** locally: `dotnet test --no-build`
+- [ ] **Tests pass** locally: `dotnet test --project Tests/UnitTests --no-build && dotnet test --project Tests/UnitTestsParallelizable --no-build`
 
 ## PR Description Template
 
@@ -70,16 +70,14 @@ dotnet build --configuration Debug --no-restore
 ### 2. Run Tests
 
 ```bash
-dotnet test --no-build --verbosity normal
+dotnet test --project Tests/UnitTests --no-build --verbosity normal && dotnet test --project Tests/UnitTestsParallelizable --no-build --verbosity normal
 ```
 
 **Expected:** All tests pass
 
 ### 3. Check Coverage
 
-Coverage is automatically collected on Linux runners in CI.
-
-**Verify coverage didn't decrease** by checking Codecov report on PR.
+Coverage collection is temporarily disabled in CI during the xUnit v3 / MTP migration.
 
 ### 4. Format Code
 

.github/workflows/README.md

@@ -2,40 +2,37 @@
 
 The repository uses multiple GitHub Actions workflows. What runs and when:
 
-### 1) Build Solution (`.github/workflows/build.yml`)
+> **Note:** Tests use xUnit v3 with Microsoft Testing Platform (MTP). The test runner is
+> configured in `global.json` via `"test": { "runner": "Microsoft.Testing.Platform" }`.
+> MTP runs test projects as standalone executables, so each OS must build its own binaries.
 
-- **Triggers**: push and pull_request to `v2_release`, `v2_develop` (ignores `**.md`); supports `workflow_call`
+### 1) Build Validation (`.github/workflows/build-validation.yml`)
+
+- **Triggers**: push and pull_request to `v2_release`, `v2_develop` (ignores `**.md`)
 - **Runner/timeout**: `ubuntu-latest`, 10 minutes
 - **Steps**:
-- Checkout and setup .NET 8.x GA
+- Checkout and setup .NET 10.x GA
 - `dotnet restore`
 - Build Debug: `dotnet build --configuration Debug --no-restore -property:NoWarn=0618%3B0612`
 - Build Release (library): `dotnet build Terminal.Gui/Terminal.Gui.csproj --configuration Release --no-incremental --force -property:NoWarn=0618%3B0612`
 - Pack Release: `dotnet pack Terminal.Gui/Terminal.Gui.csproj --configuration Release --output ./local_packages -property:NoWarn=0618%3B0612`
 - Restore NativeAot/SelfContained examples, then restore solution again
 - Build Release for `Examples/NativeAot` and `Examples/SelfContained`
 - Build Release solution
-- Upload artifacts named `build-artifacts`, retention 1 day
 
 ### 2) Build & Run Unit Tests (`.github/workflows/unit-tests.yml`)
 
 - **Triggers**: push and pull_request to `v2_release`, `v2_develop` (ignores `**.md`)
 - **Matrix**: Ubuntu/Windows/macOS
-- **Timeout**: 15 minutes per job
+- **Timeout**: 15 minutes (non-parallel), 60 minutes (parallel)
 - **Process**:
-1. Calls build workflow to build solution once
-2. Downloads build artifacts
-3. Runs `dotnet restore` (required for `--no-build` to work)
-4. **Performance optimizations**:
+1. Each OS checks out code, restores, and builds locally
+2. **Performance optimizations**:
    - Disables Windows Defender on Windows runners (significant speedup)
-   - Collects code coverage **only on Linux** (ubuntu-latest) for performance
-   - Windows and macOS skip coverage collection to reduce test time
-   - Increased blame-hang-timeout to 120s for Windows/macOS (60s for Linux)
-5. Runs two test jobs:
-   - **Non-parallel UnitTests**: `Tests/UnitTests` with blame/diag flags; `xunit.stopOnFail=false`
-   - **Parallel UnitTestsParallelizable**: `Tests/UnitTestsParallelizable` with blame/diag flags; `xunit.stopOnFail=false`
-6. Uploads test logs and diagnostic data from all runners
-7. **Uploads code coverage to Codecov only from Linux runner**
+3. Runs two test jobs:
+   - **Non-parallel UnitTests**: `Tests/UnitTests` with diagnostic output
+   - **Parallel UnitTestsParallelizable**: `Tests/UnitTestsParallelizable` with diagnostic output
+4. Uploads test logs and diagnostic data from all runners
 
 **Test results**: All tests output to unified `TestResults/` directory at repository root
 
@@ -45,16 +42,11 @@ The repository uses multiple GitHub Actions workflows. What runs and when:
 - **Matrix**: Ubuntu/Windows/macOS
 - **Timeout**: 15 minutes
 - **Process**:
-1. Calls build workflow
-2. Downloads build artifacts
-3. Runs `dotnet restore`
-4. **Performance optimizations** (same as unit tests):
+1. Each OS checks out code, restores, and builds locally
+2. **Performance optimizations**:
    - Disables Windows Defender on Windows runners
-   - Collects code coverage **only on Linux**
-   - Increased blame-hang-timeout to 120s for Windows/macOS
-5. Runs IntegrationTests with blame/diag flags; `xunit.stopOnFail=true`
-6. Uploads logs per-OS
-7. **Uploads coverage to Codecov only from Linux runner**
+3. Runs IntegrationTests with diagnostic output
+4. Uploads logs per-OS
 
 ### 4) Create Release (`.github/workflows/release.yml`)
 
@@ -95,7 +87,7 @@ The repository uses multiple GitHub Actions workflows. What runs and when:
 # Full CI sequence:
 dotnet restore
 dotnet build --configuration Debug --no-restore
-dotnet test Tests/UnitTests --no-build --verbosity normal
-dotnet test Tests/UnitTestsParallelizable --no-build --verbosity normal
+dotnet test --project Tests/UnitTests --no-build --verbosity normal
+dotnet test --project Tests/UnitTestsParallelizable --no-build --verbosity normal
 dotnet build --configuration Release --no-restore
 ```

.github/workflows/integration-tests.yml

@@ -10,15 +10,11 @@ on:
       - '**.md'
 
 jobs:
-  build:
-    uses: ./.github/workflows/quick-build.yml
-
   integration_tests:
     name: Integration Tests
     runs-on: ${{ matrix.os }}
-    needs: build
     strategy:
-      fail-fast: false  # Let all OSes finish even if one fails
+      fail-fast: false
       matrix:
         os: [ ubuntu-latest, windows-latest, macos-latest ]
     timeout-minutes: 15
@@ -33,57 +29,27 @@ jobs:
           dotnet-version: 10.x
           dotnet-quality: ga
 
-      - name: Download build artifacts
-        uses: actions/download-artifact@v4
-        with:
-          name: test-build-artifacts
-          path: .
-
       - name: Restore NuGet packages
         run: dotnet restore
 
+      - name: Build
+        run: dotnet build --no-restore
+
       - name: Disable Windows Defender (Windows only)
         if: runner.os == 'Windows'
         shell: powershell
         run: |
           Add-MpPreference -ExclusionPath "${{ github.workspace }}"
           Add-MpPreference -ExclusionProcess "dotnet.exe"
-          Add-MpPreference -ExclusionProcess "testhost.exe"
-          Add-MpPreference -ExclusionProcess "VSTest.Console.exe"
-
-      - name: Set VSTEST_DUMP_PATH
-        shell: bash
-        run: echo "VSTEST_DUMP_PATH=logs/IntegrationTests/${{ runner.os }}/" >> $GITHUB_ENV
 
       - name: Run IntegrationTests
         shell: bash
         run: |
-          if [ "${{ runner.os }}" == "Linux" ]; then
-            # Run with coverage on Linux only
-            dotnet test Tests/IntegrationTests \
-              --no-build \
-              --verbosity minimal \
-              --collect:"XPlat Code Coverage" \
-              --settings Tests/IntegrationTests/runsettings.coverage.xml \
-              --diag:logs/IntegrationTests/${{ runner.os }}/logs.txt \
-              --blame \
-              --blame-crash \
-              --blame-hang \
-              --blame-hang-timeout 60s \
-              --blame-crash-collect-always
-          else
-            # Run without coverage on Windows/macOS for speed
-            dotnet test Tests/IntegrationTests \
-              --no-build \
-              --verbosity minimal \
-              --settings Tests/IntegrationTests/runsettings.xml \
-              --diag:logs/IntegrationTests/${{ runner.os }}/logs.txt \
-              --blame \
-              --blame-crash \
-              --blame-hang \
-              --blame-hang-timeout 60s \
-              --blame-crash-collect-always
-          fi
+          dotnet test \
+            --project Tests/IntegrationTests \
+            --no-build \
+            --verbosity minimal \
+            --diagnostic --diagnostic-output-directory logs/IntegrationTests/${{ runner.os }}
 
       - name: Upload Integration Test Logs
         if: always()
@@ -93,14 +59,3 @@ jobs:
           path: |
             logs/IntegrationTests/
             TestResults/
-
-      - name: Upload Integration Tests Coverage to Codecov
-        if: matrix.os == 'ubuntu-latest' && always()
-        uses: codecov/codecov-action@v4
-        with:
-          files: TestResults/**/coverage.cobertura.xml
-          flags: integrationtests
-          name: IntegrationTests-${{ runner.os }}
-          token: ${{ secrets.CODECOV_TOKEN }}
-          fail_ci_if_error: false
-