MicrosoftKnown publishermicrosoft/MicroHack/03-Azure/01-01-App Innovation/03_GHCPAppModernization/templates/skills/dotnet-upgrade/SKILL.md

dotnet-upgrade

Skill220 starsChanged 8 days agoMITView on GitHub

Transformation rules and verification steps for upgrading .NET Framework 4.x applications to .NET 10. WHEN: upgrade to .NET 10, migrate .NET Framework, retarget TFM, convert to SDK-style project, System.Web replacement, web.config migration, packages.config to PackageReference, binding redirect cleanup. NOT for: greenfield .NET apps, NuGet version bumps within the same TFM, Azure infrastructure changes.

2 other projects use a version of this.

Adopted by

Most recently taken up by

github/awesome-copilottheir own version, first seen Oct 25, 2026
akunzai/agent-skillstheir own version, first seen Sep 19, 2026

Other versions2 projects use a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 2
github/awesome-copilot★ 41ksame name
akunzai/agent-skills★ 5same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository11 other files it gives its agents.
- 03-Azure/01-04-AI/01_Agentic_SDLC/.github/copilot-instructions.mdCopilot instructions
- 03-Azure/01-04-AI/02_Inventory_Planning_Fabric/.github/copilot-instructions.mdCopilot instructions
- 03-Azure/01-04-AI/03_Inventory_Planning_Agentic/.github/copilot-instructions.mdCopilot instructions
- 03-Azure/01-04-AI/04_Agentic_Contract_Lifecycle_Management/.github/copilot-instructions.mdCopilot instructions
- 03-Azure/01-04-AI/08_Predictive_Maintenance/.github/copilot-instructions.mdCopilot instructions
- 03-Azure/01-04-AI/11_Healthcare_Regulatory_Intelligence/.github/copilot-instructions.mdCopilot instructions
- java-upgradeSkill
- {{skill-name-kebab-case}}Skill
- skill-creatorSkill
- frontend-designSkill
- reconciliationSkill

The file

We split this skill into the rules it gives an agent

2 rules. About 0 are common, 0 are distinctive, and 2 are very specific to this project.

≈0
Common · estimate
Many files like this have a rule of this kind.
≈0
Distinctive · estimate
This author's own choices. Worth a look.
2
Very specific
Tied to their project's names, files or tools. Probably skip.

Common
Distinctive
Very specific

Very specific:
Delete AssemblyInfo.cs attributes now generated by the SDK.
line 35
Very specific:
Remove binding redirects from app/web.config (not honored on .NET 10).
line 36

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.

Files

SKILL.md

.NET Framework 4.x → .NET 10 Upgrade Rules

Purpose

Packages the API mappings, project-file rules, and verification checklist needed to retarget a .NET Framework app to .NET 10 without behavioral change.

Prerequisites

ASSESSMENT.md exists and is approved (AppCAT findings available).
.NET 10 SDK installed — verify: dotnet --list-sdks.

Procedure

Step 1 — Convert to SDK-style projects (leaf projects first)

dotnet tool install -g upgrade-assistant
upgrade-assistant upgrade .\src\{{Project}}.csproj

Migrate packages.config → PackageReference.
Delete AssemblyInfo.cs attributes now generated by the SDK.
Remove binding redirects from app/web.config (not honored on .NET 10).

Step 2 — Apply API transformation rules

Source pattern (.NET Framework)	Target pattern (.NET 10)	Notes
`System.Web.Mvc` controllers	`Microsoft.AspNetCore.Mvc`	Routing moves to endpoint routing
`Global.asax` / `HttpModule`	ASP.NET Core middleware in `Program.cs`	Order matters — replicate pipeline order
`web.config` appSettings	`appsettings.json` + `IConfiguration`	Keep keys identical to limit churn
`ConfigurationManager.AppSettings`	`IConfiguration` via DI	Inject, don't service-locate
`HttpContext.Current`	`IHttpContextAccessor`	Audit for thread-safety assumptions
WCF server (`System.ServiceModel`)	CoreWCF or gRPC/REST	Decision required — escalate to user
EF6 `ObjectContext`/EDMX	EF Core (or EF6 on .NET 10 as interim)	EDMX must be re-scaffolded for EF Core
`System.Drawing` (non-Windows)	`ImageSharp` / `SkiaSharp`	`System.Drawing.Common` is Windows-only
{{APP_SPECIFIC_RULE_1}}	{{TARGET_1}}	{{NOTE}}
{{APP_SPECIFIC_RULE_2}}	{{TARGET_2}}	{{NOTE}}

Step 3 — Verify

dotnet build zero errors across the solution
No remaining <TargetFramework>net4*</TargetFramework> (grep the repo)
No references to System.Web outside compat shims
Tests pass: dotnet test
CVE scan clean of criticals (appmod-dotnet-cve-check)

Common Pitfalls

⚠️ Upgrading hub projects first — always go leaf-first in the dependency graph, or you'll chase cascading build breaks.
⚠️ AppContext switches / legacy config quirks silently ignored on .NET 10 — search config for <runtime> elements and review each.
⚠️ Culture-sensitive string APIs changed defaults (ICU vs NLS) — pin InvariantGlobalization consciously, don't copy-paste it.
⚠️ {{APP_SPECIFIC_PITFALL}}

References

Microsoft Learn: "Upgrade from .NET Framework" / breaking changes by version
AppCAT rule documentation (linked from ASSESSMENT.md findings)

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