maui-unit-testing

name

maui-unit-testing

description

Add and improve automated tests for .NET MAUI apps, focusing on ViewModels, services, platform abstractions, and unit/integration/device test boundaries. USE FOR: xUnit projects, ViewModel tests that avoid MauiProgram.CreateMauiApp, fakes/mocks, MAUI injectable platform interfaces such as IGeolocation/IConnectivity/IPreferences/IFileSystem/ISecureStorage instead of static Essentials calls, avoiding PlatformNotSupportedException in test hosts, testing navigation/data services, Microsoft.Maui.Build.AppProjectReference for MAUI app references, and deciding what must run on device. DO NOT USE FOR: UI automation or production profiling.

MAUI Unit Testing

Use this skill to make MAUI app logic testable without requiring every test to start a device or simulator. Keep UI framework dependencies at the edges.

Workflow

1. Identify what is being tested: ViewModel, service, navigation abstraction, storage wrapper, platform capability, or UI integration.
2. For ViewModels and services, create a normal xUnit test project.
3. Introduce interfaces around platform APIs such as geolocation, preferences, secure storage, media picker, file picker, and navigation.
4. Use fakes or mocks for those interfaces in unit tests.
5. Use device/integration tests only for behavior that requires handlers, platform permissions, native controls, or OS services.
6. If a test or tooling project must reference a MAUI app project, use the AppProjectReference support provided by Microsoft.Maui.Build.AppProjectReference instead of forcing the app project to behave like a normal class library.

Test Boundary Guide

Test target	Test type
ViewModel commands, validation, state transitions	Unit test
API/data service with fake handler	Unit test
Secure storage wrapper behavior with fake storage