Repository: flutter
Issue: Cupertino sliders inconsistent hit test
Labels: platform-ios,framework,f: cupertino,f: integration_test,has reproducible steps,P2,found in release: 3.0,found in release: 3.1,team-ios,triaged-ios

## Steps to Reproduce

![Screen Shot 2022-08-10 at 12 50 27 PM](https://user-images.githubusercontent.com/4104925/183969316-43a67be2-563d-415d-9b93-e4e750d62572.png)

https://github.com/EnduringBeta/flutter-bug/tree/hit-test

In this repo, specifically the `hit-test` branch, you can run the [integration test](https://github.com/EnduringBeta/flutter-bug/blob/hit-test/integration_test/integration_test.dart#L27) on an Android and iOS device. It tries to find the 3 (adaptive) sliders. Android passes for me, but iOS fails on the hit test lines:

```dart
Finder slidersFinder = find.byType(Slider).hitTestable();
expect(slidersFinder, findsNWidgets(3));
```

If I'm just misunderstanding how hit tests work, that's fine. I wasn't able to easily find a reason why this would be happening. Perhaps it's related to the Cupertino sliders being mostly a thin line with the thumb being the only interactable part?

**Expected results:** All tests passing all the time

**Actual results:** Only the middle Cupertino slider is found when `hitTestable()` is used.

*(Note: the screenshot is after moving the sliders; original positions are 1, 5, 9. So slider 2 has its thumb in the center for testing, which may be key.)*

<details>
<summary>Code sample</summary>

See link to repo and branch above.

</details>

<details>
  <summary>Logs</summary>

```
[  +55 ms] executing: sysctl hw.optional.arm64
[  +21 ms] Exit code 0 from: sysctl hw.optional.arm64
[        ] hw.optional.arm64: 1
[   +4 ms] executing: [/Users/ross/projects/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[  +48 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] f1875d570e39de09040c8f79aa13cc56baab8db1
[        ] executing: [/Users/ross/projects/flutter/] git tag --points-at f1875d570e39de09040c8f79aa13cc56baab8db1
[  +81 ms] Exit code 0 from: git tag --points-at f1875d570e39de09040c8f79aa13cc56baab8db1
[        ] 3.0.5
[   +4 ms] executing: [/Users/ross/projects/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[  +13 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] origin/stable
[        ] executing: [/Users/ross/projects/flutter/] git ls-remote --get-url origin
[  +10 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[  +54 ms] executing: [/Users/ross/projects/flutter/] git rev-parse --abbrev-ref HEAD
[  +15 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] stable
[   +2 ms] executing: sw_vers -productName
[  +17 ms] Exit code 0 from: sw_vers -productName
[        ] macOS
[        ] executing: sw_vers -productVersion
[  +10 ms] Exit code 0 from: sw_vers -productVersion
[        ] 12.5
[        ] executing: sw_vers -buildVersion
[   +8 ms] Exit code 0 from: sw_vers -buildVersion
[        ] 21G72
[        ] executing: uname -m
[   +3 ms] Exit code 0 from: uname -m
[        ] arm64
[~~~ REMOVED A BUNCH BECAUSE MY COMMENT WAS TOO LONG ~~~]
[   +1 ms] Updating assets
[  +41 ms] Syncing files to device iPhone 13...
[        ] <- reset
[        ] Compiling dart to kernel with 0 updated files
[        ] Processing bundle.
[        ] <- recompile package:flutter_bug/main.dart 8626e41f-3a71-4807-bc58-23e5de8d7436
[        ] <- 8626e41f-3a71-4807-bc58-23e5de8d7436
[        ] Bundle processing done.
[ +111 ms] Updating files.
[        ] DevFS: Sync finished
[        ] Syncing files to device iPhone 13... (completed in 115ms)
[        ] Synced 0.0MB.
[   +1 ms] <- accept
[   +4 ms] Connected to _flutterView/0x140033020.
[   +3 ms] Flutter run key commands.
[        ] r Hot reload. 🔥🔥🔥
[        ] R Hot restart.
[        ] h List all available interactive commands.
[        ] d Detach (terminate "flutter run" but leave application running).
[        ] c Clear the screen
[        ] q Quit (terminate the application on the device).
[        ] 💪 Running with sound null safety 💪
[        ] An Observatory debugger and profiler on iPhone 13 is available at: http://127.0.0.1:62517/6GvH3yvnU1c=/
[ +120 ms] The Flutter DevTools debugger and profiler on iPhone 13 is available at: http://127.0.0.1:9101?uri=http://127.0.0.1:62517/6GvH3yvnU1c=/
```

<!--
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```
Analyzing flutter-bug...                                                
No issues found! (ran in 1.3s)
```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
Flutter (Channel stable, 3.0.5, on macOS 12.5 21G72 darwin-arm, locale en-US)
    • Flutter version 3.0.5 at /Users/ross/projects/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision f1875d570e (4 weeks ago), 2022-07-13 11:24:16 -0700
    • Engine revision e85ea0e79c
    • Dart version 2.17.6
    • DevTools version 2.12.2

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0)
    • Android SDK at /Users/ross/Library/Android/sdk
    • Platform android-33, build-tools 33.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.4.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)

[✓] Connected device (4 available)
    • EnduringBeta iPhone 8 (mobile) • 69d439b6aa98fea73463dd9699ed08cd3b373265 • ios            • iOS 15.6 19G71
    • iPhone 13 (mobile)             • 77EAB8EF-4DB7-4E07-A495-2C0717E33D40     • ios            • com.apple.CoreSimulator.SimRuntime.iOS-15-5 (simulator)
    • macOS (desktop)                • macos                                    • darwin-arm64   • macOS 12.5 21G72 darwin-arm
    • Chrome (web)                   • chrome                                   • web-javascript • Google Chrome 104.0.5112.79

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!
```

</details>