csharp-expert

C# Expert

Governance: CodENavi Full Workspace v2. Skill of codenavi-agent; inherit AGENTS.md. Lifecycle: BRIEFING → RECON → PLAN → EXECUTE → VERIFY → DEBRIEF. Source roles/workers are internal lenses. Never create agent identities or bypass runtime secret/permission gates.

Governance: CodENavi Full Workspace v2. A skill of codenavi-agent. It creates no other agent identity.

Write and review C# source on the current stable .NET release. Module map: references/INDEX.md.

Mission

New C# uses C# 14 on net10.0. An existing project keeps the TargetFramework and LangVersion it already declares. Do not retarget because a newer SDK exists. Version pin and refresh rule: references/current-release.md.

Workflow

1. Read every TargetFramework and LangVersion in the SDK-style .csproj files this change touches. Map and idiom rules: references/project-and-idioms.md.
2. For a new project, set TargetFramework to net10.0 and leave LangVersion unset so the default is C# 14. For an existing project, write only syntax that its TFM and LangVersion accept.
3. Apply C# 14 features only when step 2 allows them. Feature rules: references/csharp-14.md.
4. Keep the change inside C# source, the .csproj that compiles it, and the C# test project that covers it.
5. Verify with the commands in references/verify.md. A compile failure blocks any claim that the code is done.

Rules

1. Enable nullable on a new file when the project sets <Nullable>enable</Nullable>, and on every file of a project this skill creates.
2. Do not set LangVersion to preview. Do not use C# 15 or net11.0 unless the repository already declares that target.
3. Prefer the BCL or a package the project already references. Add a package only when the user asked for that dependency.
4. Match the project's namespace style, file layout, and analyzer settings.

Example

User says: "adicione um contador com get customizado neste tipo." Result: a field-backed property when the project is C# 14.

public int Count
{
    get => field;
    set => field = value < 0 ? 0 : value;
}

On net8.0 the same request uses an explicit backing field. The TFM stays net8.0.

Stop

Stop when the change is not C#/.NET source, the .csproj TFM cannot be read, or dotnet is absent and the syntax must be compiled to confirm. Say which input is missing.

Output

Report the detected TFM, the language version used, the files changed, and the dotnet build or dotnet test result from references/verify.md.

Provenance and source freshness: provenance.