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Add AddResourceDictionary API and cross-app testing sample#135

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mattleibow wants to merge 19 commits into
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mattleibow/visual-runner-as-service
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Add AddResourceDictionary API and cross-app testing sample#135
mattleibow wants to merge 19 commits into
mainfrom
mattleibow/visual-runner-as-service

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@mattleibow mattleibow commented May 21, 2026 •
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Summary

Enables testing custom controls, ViewModels, and services inside a real MAUI app by referencing the app as a library from a separate test project. The app's styles, DI container, and resources are fully available in tests.

Key changes

  1. AddResourceDictionary<T>() API — Register app resource dictionaries (Colors, Styles) into the visual test runner so {StaticResource} resolves correctly during tests.

  2. Page-level runner resources — Runner styles moved from Application.Resources to page-level VisualRunnerResources.xaml, preventing conflicts with app styles.

  3. Library-mode project reference — Test project references the app with <AdditionalProperties>Configuration=Library$(Configuration)</AdditionalProperties>, which triggers the app-side targets to build as a library (no entry points, no icons, no packaging).

  4. TestingWorkarounds.targets (drop-in files) — Two .targets files handle all MSBuild workarounds:

    • App-side: Detects library mode, sets OutputType=Library, strips platform entry points, removes icons/splash, disables packaging. Propagates Configuration to transitive refs to prevent parallel build races.
    • Test-side: Strips leaked Resizetizer items and fixes Windows PRI generation for the referenced app.

  5. Sample DeviceTestingKitApp.AppTests — 10 NUnit tests demonstrating the pattern: page creation with styles, binding context, custom controls, command wiring, live modal navigation.

  6. Documentation — Full guide at docs/articles/testing-with-app-resources.md with drop-in code fences for both targets files.

Upstream issues filed

Architecture

Test App (AppTests)
  └── ProjectReference: DeviceTestingKitApp (Configuration=LibraryRelease)
        ├── OutputType=Library (no entry point)
        ├── MauiIcon/SplashScreen removed
        ├── Platform entry points stripped
        └── ProjectReference: MauiLibrary (Configuration=LibraryRelease)
              └── Separate intermediate paths (no parallel race)

What users do

  1. Add TestingWorkarounds.targets to their app (imports via csproj)
  2. Add TestingWorkarounds.targets to their test project
  3. Reference app with <AdditionalProperties>Configuration=Library$(Configuration)</AdditionalProperties>
  4. Call AddResourceDictionary<Colors>() and AddResourceDictionary<Styles>() in test app setup
  5. Write tests that create real pages/controls with full style resolution

Once upstream fixes ship

  • Remove _RemoveImportedAppResizetizerItems from test-side targets (after maui#35575)
  • Remove _FixWindowsPriForAppReference from test-side targets (after WindowsAppSDK fix)
  • App-side targets remain permanently (they ARE the library-mode mechanism)

This was referenced May 22, 2026
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mattleibow and others added 15 commits May 22, 2026 21:29
@mattleibow
Add cross-app test sample with library-mode project reference
cf7716e 
- Add DeviceTestingKitApp.AppTests project that references the real app
  as a library (IsTestLibrary=true strips entry points and resources)
- Add AddResourceDictionary<T>() convenience method on the config builder
  for cleaner usage in lambda expressions
- Add x:Class to sample app's Colors.xaml and Styles.xaml to make them
  instantiable from test projects
- Add NUnit tests verifying MainPage instantiation and style resolution
- Wire up library-mode MSBuild in DeviceTestingKitApp.csproj (conditional
  OutputType, strip MauiIcon/Splash/Images/Fonts/Assets when IsTestLibrary)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Extract shared AddDeviceTestingKitAppServices and remove redundant fonts
5301e84 
- Move service/VM/page/font registration into a shared extension method
  (ServiceCollectionExtensions.AddDeviceTestingKitAppServices) so both the
  real app and test projects call the same code
- Remove font files from AppTests (they flow from the app library reference)
- Simplify AppTests MauiProgram to just call the shared method
- Reduce IsTestLibrary conditions to only MauiIcon and MauiSplashScreen
  (images, fonts, and raw assets don't conflict)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix resource merge ordering and converter crash during teardown
b5d6f04 
- Merge each resource dictionary into Application.Resources immediately
  after creation (not batch-then-merge). This ensures Styles.xaml can
  resolve {StaticResource Primary} from Colors.xaml during its
  InitializeComponent().
- Replace Application.Current.Resources lookups in RunStatusToColorConverter
  with hardcoded colors. Resources are now page-level scoped so the
  converter cannot reach them via Application.Resources, and during app
  teardown the lookup would throw KeyNotFoundException.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Add counter button and command binding tests to AppTests
5c619e7 
- Verify CounterButton exists in MainPage visual tree
- Test initial button text renders correctly via converter
- Test IncrementCommand is wired to button and updates VM state
- Test multiple command executions via button.Command binding
- Add helper FindByAutomationId<T> for visual tree traversal

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Add live modal navigation test that verifies binding updates
30b24f4 
Push MainPage as a modal onto the runner's navigation stack, then
execute the counter button's command and assert that the Button.Text
binding updates via the converter (Click me! → Clicked 1 time → ...).
Runs on the UI thread via MainThread.InvokeOnMainThreadAsync to satisfy
UIKit thread affinity requirements.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Add documentation for testing with app resources (library mode)
4618849 
Explains the full pattern: making the app buildable as a library,
adding x:Class to resource dictionaries, creating the test project,
configuring AddResourceDictionary, and writing live binding tests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix Resizetizer duplicate appicon error in full solution builds
687fa30 
Resizetizer's transitive GetMauiItems target doesn't pass AdditionalProperties
from ProjectReference, so the app's MauiIcon leaks into the test project even
when IsTestLibrary=true strips it from the app's own build. Add a target that
removes the imported appicon after ResizetizeCollectItems runs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Switch to Configuration-based library mode and extract TestingWorkaro…
cb0a7b9 
…unds.targets

Adopt Pedro's pattern: Configuration=Library$(Configuration) on ProjectReference
triggers IsTestProject=true in the app. This naturally gives separate intermediate
paths and eliminates file-locking race conditions during parallel solution builds.

Extract all MSBuild workaround logic into TestingWorkarounds.targets files in each
project folder to keep csproj files clean. Includes per-platform entry point
stripping, Resizetizer item removal, and Windows PRI fix.

Update documentation to reflect the new pattern.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Remove accidentally committed build artifacts
3f39eb8 
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix Resizetizer workaround path separator for Windows
002da35 
Normalize backslashes to forward slashes before Contains() check so
the workaround works on both macOS and Windows CI agents.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Document post-fix state when dotnet/maui#35575 ships
46663cf 
Add section explaining what to remove from TestingWorkarounds.targets
once the Resizetizer fix lands, and what must remain (Windows PRI
workaround and the app-side library mode targets).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Rewrite docs with drop-in targets and workaround explanation
0fae579 
Include complete TestingWorkarounds.targets as code fences that users
can copy directly. Explain why Configuration=Library$(Configuration) is
needed. Document the Windows PRI and Resizetizer issues with links to
dotnet/maui#35574 and #35575. Add section on what to remove once fix ships.

Tracking: #136

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Remove accidentally committed build artifacts and ignore lib_ dirs
25ccafe 
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix parallel build race: propagate Configuration to transitive refs
65253bf 
When the app builds in library mode (Configuration=LibraryRelease), its
ProjectReferences to MauiLibrary/Library were still building as plain
Release. This caused a file-locking race with the solution-level build
of MauiLibrary (same config, same intermediate path, two MSBuild nodes
racing on XamlCTask).

Fix: propagate Configuration=LibraryRelease to transitive references
via AdditionalProperties when IsTestProject=true, giving them separate
output paths that cannot conflict with the solution-level build.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Revert Configuration propagation to transitive refs
db9c4a5 
Propagating Configuration=Library$(Configuration) to transitive
references (MauiLibrary) caused APPX1101 duplicate payload errors on
Windows: the test app sees MauiLibrary.dll from both debug/ and
librarydebug/ output paths.

The original XamlCTask parallel race was a one-off flaky failure
(passed on ADO, failed once on GH Actions). Removing the propagation
fixes the Windows packaging error.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow mattleibow force-pushed the mattleibow/visual-runner-as-service branch from 6500747 to db9c4a5 Compare May 22, 2026 19:32
mattleibow and others added 4 commits May 22, 2026 21:47
@mattleibow
Add library style resolution tests and register CounterStyles
233b3cb 
Verify that styles from MauiLibrary's CounterStyles.xaml flow correctly
into the test app via AddResourceDictionary. Tests confirm:
- CounterButtonColor (#FF6B6B) is resolvable from Application.Resources
- CounterButtonTextColor (white) is resolvable
- Live button actually renders with the coral background, not default purple

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Rewrite docs as customer-focused walkthrough
0da0cef 
Remove internal MSBuild details (why Configuration=Library, Resizetizer/PRI
internals) and restructure as a quick-start guide for developers who want
to test their app's controls and services on device with real styles.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix docs: add missing package refs and correct resource scoping claim
799bb81 
- Add DeviceRunners.Testing.Targets, VisualRunners.NUnit, and
  VisualRunners.Maui as PackageReference (not ProjectReference)
- Correct resource scoping description: implicit styles still apply
  globally by design

Found by Opus 4.7 and GPT 5.5 review.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@mattleibow
Fix doc prereqs, add GenerateTestingPlatformEntryPoint, fix helper ar…
41bea0c 
…m order

- Change prereq from .NET 9+ to .NET 10+ (all examples use net10.0 TFMs)
- Add GenerateTestingPlatformEntryPoint=false to csproj snippet
- Fix FindByAutomationId pattern match: ContentPage arm before IContentView
- Add note that helper only covers simple ContentPage/Layout hierarchies

Found by Opus 4.7 and GPT 5.5 review.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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