sdk-style-conversion

name	sdk-style-conversion
description	Converts legacy .NET projects to SDK-style project format. Use when user wants to convert to SDK-style, modernize project files, or migrate from legacy csproj format. Does not change target frameworks.
requires-extension	upgrade-dotnet
metadata	{"discovery":"scenario","traits":".NET|CSharp|VisualBasic|DotNetCore|DotNetFramework","scenarioTraitsSet":[".NET"]}

SDK-style Project Conversion

1. Assessment

Scan the solution to identify which projects need conversion and what complications to expect. Capture findings in assessment.md.

How to Identify Non-SDK-Style Projects

A project is non-SDK-style if it has any of:

• No Sdk attribute on the <Project> element
• Explicit file includes (<Compile Include="..."> for every source file)
• packages.config file in the project directory
• <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" /> or similar explicit tool imports

Patterns to Identify

For each non-SDK-style project, record:

Pattern	What to Record
packages.config	Present? — must be migrated to PackageReference
Explicit file includes (Compile, Content, None, EmbeddedResource)	Count — SDK-style uses globbing, these become implicit
Custom Import elements	Which targets are imported — may need preservation
AssemblyInfo.cs with assembly attributes	SDK-style auto-generates these — potential duplication
Multi-targeting (TargetFrameworks plural)	Already SDK-like, may be partial conversion
WPF/WinForms markers (<UseWPF>, <UseWindowsForms>, XAML files)	Needs Microsoft.NET.Sdk.WindowsDesktop or net*-windows TFM handling
Web project type GUIDs ({349c5851-...})	ASP.NET projects have special post-conversion considerations
Custom build events or targets	Must be preserved through conversion

Risk Indicators

Flag these as higher complexity:

• ASP.NET Framework web projects: SDK-style conversion is technically possible, but .NET tooling (Visual Studio, dotnet build) does not fully support SDK-style projects targeting ASP.NET Framework (non-Core). Custom MSBuild techniques or workarounds may be needed to maintain build and publish behavior. NuGet compatibility issues can also arise post-conversion
• Heavy custom MSBuild logic: Custom targets, conditional imports, or property manipulation that might conflict with SDK defaults
• Shared projects or linked files: File linking patterns change in SDK-style

Assessment Output

Create assessment.md in the workflow folder with this structure:

# Assessment: SDK-style Conversion

## Projects to Convert
| Project | Path | packages.config | Custom Imports | Special Type | Risk |
|---------|------|----------------|----------------|-------------|------|
| MyApp.Core | src/Core/MyApp.Core.csproj | Yes | None | Class library | Low |
| MyApp.Web | src/Web/MyApp.Web.csproj | Yes | 2 custom targets | ASP.NET | High |

## Already SDK-style (no action needed)
- [list or "none"]

## Baseline
- Solution builds: Yes/No
- Warning count: [number]

## Key Findings
- [Notable patterns, risks, or decisions needed]

2. Planning

Based on the assessment, create plan.md with tasks ordered topologically (leaf dependencies first, so each project can build after conversion).

For each task include:

• Which projects or groups of projects are covered
• What complications are expected (packages.config, custom imports, special project types)
• Risk level and anything requiring user decision

Hard constraint: Do not change TargetFramework during conversion — that is a separate scenario (dotnet-version-upgrade).

3. Execution

Execute the plan task by task. For any task that involves converting a project to SDK-style, apply the converting-to-sdk-style feature skill. It provides a dedicated conversion tool and a two-phase workflow (planning + execution with per-project checklist).

Verify the solution builds after each project or group is converted — catching errors early prevents cascading failures in dependent projects.

4. Validation

• Build the full solution — zero errors required (or no regressions from baseline)
• All packages.config files removed from converted projects
• No TargetFramework values changed
• If the project had tests, run them and report results