Add resilience to UI tests for frozen/unresponsive apps by PureWeen · Pull Request #34023 · dotnet/maui

PureWeen · 2026-02-12T17:56:57Z

Summary

When an app enters an infinite loop (e.g., layout cycle on iOS), WDA (WebDriverAgent) blocks forever waiting for the main thread to become idle. This causes Appium commands to hang indefinitely, which in turn hangs the entire test run.

This PR adds resilience to prevent test hangs and allows graceful failure with clear error messages.

Changes

HelperExtensions.cs

Add RunWithTimeout wrapper (45s hard limit) around all Appium commands
Wrap Tap(), Click(), and Wait() query calls with timeout
Uses CancellationTokenSource for proper cleanup hygiene
Logs warning about orphaned threads when timeout occurs
Throws clear TimeoutException when app is unresponsive
Uses Task.Run + GetAwaiter().GetResult() to properly unwrap exceptions

AppiumLifecycleActions.cs

Add ForceCloseApp command using OS-level termination:
- iOS: xcrun simctl terminate
- Android: adb shell am force-stop
- Mac: osascript quit
Wrap CloseApp with 15s timeout, auto-falls back to ForceCloseApp
Bypasses WDA when normal Appium termination hangs

UITestBase.cs

Catch TimeoutException for unresponsive apps in TearDown
Force-terminate and reset session when app freezes
Allows subsequent tests to continue instead of hanging forever

Result

Before: Tests hang indefinitely when app freezes, blocking entire CI run

After: Tests fail gracefully after 45s with clear error message:

TimeoutException: An Appium command did not complete within 45s. 
The application may be unresponsive (e.g., due to an infinite layout loop).

Testing

Tested with Issue32586 test case that triggers infinite layout cycle on iOS:

Test correctly times out after 45s (previously hung forever)
Clear error message indicates app is unresponsive
Subsequent tests can continue (session is reset via ForceCloseApp)

Notes

45s timeout balances avoiding false positives on slow CI (normal operations: 10-30s) while still failing reasonably fast when app is truly frozen
Thread leak is acceptable: background Task.Run threads may remain blocked after timeout, but ForceCloseApp kills the process which unblocks the socket
Debug logging helps diagnose issues in CI

PureWeen · 2026-02-12T18:00:03Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-12T18:00:15Z

Azure Pipelines successfully started running 1 pipeline(s).

Copilot

Pull request overview

This PR improves the reliability of the Appium-based UI test infrastructure by preventing indefinite hangs when the app under test becomes frozen/unresponsive (e.g., iOS layout cycles that block WDA), and by adding a force-termination fallback path.

Changes:

Add a hard timeout wrapper around select Appium UI interactions and polling queries to fail fast instead of hanging indefinitely.
Add a new forceCloseApp command that bypasses Appium/WDA by terminating the app via OS-level commands, and use it as a fallback when closeApp hangs/fails.
Update NUnit TearDown handling to attempt force-close/reset when unresponsive timeouts are detected.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 8 comments.

File	Description
src/TestUtils/src/UITest.NUnit/UITestBase.cs	Adds TearDown handling intended to force-close/reset when the app becomes unresponsive.
src/TestUtils/src/UITest.Appium/HelperExtensions.cs	Introduces `RunWithTimeout` and applies it to `Tap`/`Click` and to the internal `Wait(...)` polling query calls.
src/TestUtils/src/UITest.Appium/Actions/AppiumLifecycleActions.cs	Adds `forceCloseApp` and wraps `closeApp` with a 15s timeout + fallback to force-close.

src/TestUtils/src/UITest.Appium/Actions/AppiumLifecycleActions.cs

src/TestUtils/src/UITest.NUnit/UITestBase.cs

src/TestUtils/src/UITest.Appium/HelperExtensions.cs

Copilot · 2026-02-12T18:07:16Z

src/TestUtils/src/UITest.Appium/HelperExtensions.cs

+				if (!task.Wait(timeout.Value))
+				{
+					// Signal cancellation (Appium driver won't respect it, but good hygiene)
+					cts.Cancel();
+


On timeout, this code throws while the background task continues running and is never observed. If the underlying Appium call later faults, it can surface as an unobserved task exception (noise/flakiness). Consider attaching a continuation in the timeout path to observe/log task.Exception (OnlyOnFaulted) before throwing.

src/TestUtils/src/UITest.NUnit/UITestBase.cs

src/TestUtils/src/UITest.Appium/Actions/AppiumLifecycleActions.cs

PureWeen · 2026-02-17T18:09:10Z

/azp run maui-pr-uitests, maui-pr-devicetests

azure-pipelines · 2026-02-17T18:09:28Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-02-18T17:05:04Z

/azp run maui-pr-uitests, maui-pr-devicetests

azure-pipelines · 2026-02-18T17:05:21Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-02-18T20:46:24Z

/azp run maui-pr-uitests, maui-pr-devicetests

azure-pipelines · 2026-02-18T20:46:44Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-02-18T23:25:23Z

/azp run maui-pr-uitests, maui-pr-devicetests

azure-pipelines · 2026-02-18T23:25:37Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-02-19T04:29:59Z

/azp run

PureWeen · 2026-02-22T03:39:38Z

/azp run

azure-pipelines · 2026-02-22T03:39:56Z

Azure Pipelines successfully started running 3 pipeline(s).

Relocate from copilot-instructions.md to uitests.instructions.md since these commands are only relevant in the UI testing context. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-02-22T07:43:31Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-22T07:43:41Z

Azure Pipelines successfully started running 1 pipeline(s).

…outs - Switch from VerticalStackLayout to Grid with star row so RefreshView gets remaining screen space. VerticalStackLayout gave ScrollView only its content height, preventing Android SwipeRefreshLayout from detecting pull-to-refresh gesture. - Bump Issue1905, Issue3275 catalyst timeouts from 90s to 120s (CI is slower than local — 33s local, needs headroom for CI). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-02-22T15:46:06Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-22T15:46:16Z

Azure Pipelines successfully started running 1 pipeline(s).

PureWeen · 2026-02-22T20:17:10Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-22T20:17:21Z

Azure Pipelines successfully started running 1 pipeline(s).

PureWeen · 2026-02-22T20:27:10Z

/azp run maui-pr-uitests
/azp run maui-pr-devicetests

azure-pipelines · 2026-02-22T20:27:16Z

No pipelines are associated with this pull request.

PureWeen · 2026-02-22T20:28:42Z

/azp run

azure-pipelines · 2026-02-22T20:29:02Z

Azure Pipelines successfully started running 3 pipeline(s).

PureWeen · 2026-02-22T20:35:22Z

/azp run maui-pr-uitests, maui-pr-devicetests

azure-pipelines · 2026-02-22T20:35:33Z

Azure Pipelines successfully started running 2 pipeline(s).

…e RunWithTimeout from Wait() - Issue1905: Reduce ListView from 1000 to 20 items, reduce refresh delay from 5s to 1s - Issue3275: Rewrite as self-verifying test with 50 items (was 500), no multi-page navigation - Issue3001: Reduce nested Grid from 5 levels (1024 labels) to 3 levels (64 labels) - Wait(): Remove RunWithTimeout wrapping to match main branch behavior — prevents killing slow FindElement calls that the mac2 driver needs for accessibility tree walks. Frozen-app protection remains on Tap/Click/GetText actions. All 8 tests pass on iOS (2-40s each). Catalyst local environment is degraded but the reduced accessibility trees should resolve CI catalyst failures. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…bility trees Issue1905: Rewritten as self-verifying ContentPage. Calls BeginRefresh() programmatically and checks RefreshCommand completes. Removed 1000-item ListView that caused mac2 driver to choke on accessibility tree walks. Issue3001: Reduced nested grid depth from 5 levels (1024 labels) to 3 levels (64 labels). Same test logic: tap Start, verify Ready label appears. Issue3275: Rewritten as self-verifying ContentPage. Creates a ListView with RecycleElement caching (50 items instead of 500), performs ScrollTo, nulls BindingContext to verify no NRE. No navigation needed — the bug is triggered by ScrollTo + null BindingContext, not by page navigation. All 3 tests pass on iOS in under 10 seconds (previously 120s+ timeouts). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-02-23T09:07:45Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-23T09:07:56Z

Azure Pipelines successfully started running 1 pipeline(s).

Issue1905: Restored TestNavigationPage base class and On<iOS>().SetPrefersLargeTitles(true) — the specific trigger for the bug. Content page is pushed onto NavigationPage stack as in the original. Issue3275: Restored navigation lifecycle (PushModalAsync/PopModalAsync), ContextActions with command bindings on ViewCells, and BindingContext = null in OnDisappearing. These are all part of the original NRE trigger path. Issue3001: Increased maxLevel from 3 back to 4 (256 labels instead of 64) for better sensitivity to performance regressions while still avoiding the 1024-label accessibility tree that caused catalyst timeouts. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-02-23T15:26:19Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-23T15:26:31Z

Azure Pipelines successfully started running 1 pipeline(s).

PureWeen · 2026-02-23T15:28:04Z

/azp run maui-pr-uitests

azure-pipelines · 2026-02-23T15:28:14Z

Azure Pipelines successfully started running 1 pipeline(s).

Issue3275: Restore NavigationPage + PushAsync + TapBackArrow pattern to preserve the original navigation lifecycle that triggers the NRE. MainPage.OnAppearing detects successful return as the verification. Issue16910: Make OnRunTestClicked async with Task.Yield() to let the XAML TwoWay binding engine propagate values before checking, instead of synchronous in-handler check that bypasses the binding pipeline. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Issue16910: Restore original Appium-driven verification pattern (StartRefreshing/StopRefreshing buttons, grid.Remove/grid.Insert for labels, Appium WaitForElement for visual tree verification). Only change from original: ScrollView instead of CollectionView to avoid catalyst accessibility tree bloat. Issue3001: Fix wrong comment (was '3 levels' for maxLevel=4, now correctly says '4 levels: 4^4 = 256 labels'). Tighten timeout from 45s to 15s to preserve performance regression detection. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-02-23T21:40:48Z

/azp run maui-pr, maui-pr-uitests

azure-pipelines · 2026-02-23T21:41:04Z

Azure Pipelines successfully started running 2 pipeline(s).

Copilot AI review requested due to automatic review settings February 12, 2026 17:56

Copilot started reviewing on behalf of PureWeen February 12, 2026 17:58 View session

PureWeen added the area-ai-agents Copilot CLI agents, agent skills, AI-assisted development label Feb 12, 2026

Copilot AI reviewed Feb 12, 2026

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PureWeen mentioned this pull request Feb 12, 2026

[iOS] MauiView: Round SafeArea insets to pixels to fix infinite layout cycle #34024

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PureWeen marked this pull request as draft February 12, 2026 19:12

kubaflo marked this pull request as ready for review February 13, 2026 12:48

kubaflo previously approved these changes Feb 13, 2026

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PureWeen added this to the .NET 10 SR5 milestone Feb 17, 2026

PureWeen added this to MAUI SDK Ongoing Feb 17, 2026

github-project-automation bot moved this to Todo in MAUI SDK Ongoing Feb 17, 2026

PureWeen moved this from Todo to Approved in MAUI SDK Ongoing Feb 17, 2026

PureWeen dismissed kubaflo’s stale review via 3c5fc28 February 18, 2026 16:53

PureWeen force-pushed the uitest-resilience-frozen-apps branch from 60d8eed to 3c5fc28 Compare February 18, 2026 16:53

kubaflo previously approved these changes Feb 18, 2026

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PureWeen dismissed kubaflo’s stale review via 65b09ab February 18, 2026 23:24

Move dangerous commands warning to uitests instructions

53fd62f

Relocate from copilot-instructions.md to uitests.instructions.md since these commands are only relevant in the UI testing context. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen and others added 2 commits February 22, 2026 21:18

build-analysis bot mentioned this pull request Feb 23, 2026

File upload failed even after retry dotnet/dnceng#1916

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PureWeen commented Feb 12, 2026

Summary

Changes

HelperExtensions.cs

AppiumLifecycleActions.cs

UITestBase.cs

Result

Testing

Notes

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Pull request overview

Reviewed changes

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