/build-giraffe-web-app

name: build-giraffe-web-app
description: Build or modify a Giraffe web application in idiomatic F#, using composable HttpHandler functions, explicit ASP.NET Core integration, configuration, authentication, and focused endpoint tests.

Build Giraffe Web App

Use Giraffe's functional handler composition as the HTTP boundary, not as a reason to place business rules in route declarations.

Source Check

Inspect the existing host, package lock or project references, handlers, tests, and configuration first. Use the [Giraffe documentation](https://giraffe.wiki/) and [ASP.NET Core documentation](https://learn.microsoft.com/aspnet/core/) when repository evidence is insufficient.

Workflow

1. Confirm that Giraffe is already selected; otherwise use `dotnet:choose-fsharp-web-framework` first. 2. Keep request parsing, authentication context, and response writing in narrow `HttpHandler` functions. Compose reusable HTTP concerns with `>=>` only when they have one clear request-pipeline responsibility. 3. Put domain transformations and external-dependency contracts in separately testable F# modules. Pass dependencies explicitly or resolve genuine host dependencies at a clear ASP.NET Core boundary. 4. Preserve ASP.NET Core ordering: routing, authentication, authorization, static files, exception handling, and Giraffe middleware must remain aligned with the application's existing host contract. 5. Make response errors specific: route, failed input or dependency, and the safe client-facing outcome. Do not leak secrets or internal exception details. 6. Test pure domain behavior first, then handler or host behavior for route, authorization, binding, status, and response regressions.

Validation

Use the narrowest project commands available, normally:

dotnet build <web-project.fsproj>
dotnet test <test-project.fsproj>

Do not run a live deployment or add a replacement middleware stack merely to exercise one handler.

Boundaries

• Keep `.fsproj` file order valid as modules are added.
• Use ordinary ASP.NET Core middleware and services when that is the existing

integration surface; do not reimplement them as Giraffe helpers.

• Route Azure hosting, identity, resource configuration, and deployment work to

the official Azure Skills plugin through `cloud-deployment-routing-workflow`.