[device_info] null safety version crashes for apps that opt into null safety

[MaikuB]

Steps to Reproduce

1. Update example app for device_info plugin to opt into null safety by changing the SDK constraints
2. Run app on Android and app crashes

Note: I have fork with these changes that can reproduce the issue at https://github.com/MaikuB/plugins/tree/null_safety_device_info_crash/packages/device_info/device_info. Another observation is that going to the directory of the example app to run the integration test by running the following command

flutter drive \
  --driver=test_driver/integration_test.dart \
  --target=integration_test/device_info_test.dart

does not indicate failure. In fact, all tests are reported to have passed.

Expected results:

Able to receive info on the device

Actual results:

App crashes, it looks like platform channel is receiving null values from the native side

Logs

[ +707 ms] I/flutter ( 6978): type 'Null' is not a subtype of type 'String'
[        ] I/flutter ( 6978): #0      new List.from (dart:core-patch/array_patch.dart:40:5)
[        ] I/flutter ( 6978): #1      AndroidDeviceInfo._fromList (package:device_info_platform_interface/model/android_device_info.dart:144:12)
[        ] I/flutter ( 6978): #2      AndroidDeviceInfo.fromMap (package:device_info_platform_interface/model/android_device_info.dart:137:23)
[        ] I/flutter ( 6978): #3      MethodChannelDeviceInfo.androidInfo (package:device_info_platform_interface/method_channel/method_channel_device_info.dart:16:30)
[        ] I/flutter ( 6978): <asynchronous suspension>
[        ] I/flutter ( 6978): #4      DeviceInfoPlugin.androidInfo (package:device_info/device_info.dart:25:11)
[        ] I/flutter ( 6978): <asynchronous suspension>
[        ] I/flutter ( 6978): #5      _MyAppState.initPlatformState (package:device_info_example/main.dart:43:44)

[✓] Flutter (Channel beta, 1.26.0-17.6.pre, on macOS 11.2.1 20D74 darwin-x64,
    locale en-AU)
    • Flutter version 1.26.0-17.6.pre at /Users/michaelbui/flutter
    • Framework revision a29104a69b (17 hours ago), 2021-02-16 09:26:56 -0800
    • Engine revision 21fa8bb99e
    • Dart version 2.12.0 (build 2.12.0-259.12.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /Users/michaelbui/Library/Android/sdk
    • Platform android-30, build-tools 30.0.2
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.1

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • 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
      1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.53.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.19.0

[✓] Connected device (2 available)
    • sdk gphone x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API
      30) (emulator)
    • Chrome (web)            • chrome        • web-javascript • Google Chrome
      88.0.4324.182

[darshankawar]

@MaikuB
I followed your steps and modified plugin's sdk constraint to null safety, but while running, getting below errors:

Launching lib/main.dart on sdk gphone x86 arm in debug mode...
Running Gradle task 'assembleDebug'...
Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

 - package:device_info
 - package:device_info_platform_interface
 - package:plugin_platform_interface

For solutions, see https://dart.dev/go/unsound-null-safety
lib/main.dart:56:21: Error: Non-nullable variable 'deviceData' must be assigned before it can be used.
      _deviceData = deviceData;
                    ^^^^^^^^^^


FAILURE: Build failed with an except

environment:
  sdk: ">=2.12.0-0 <3.0.0"

Used plugin's official repo example.

Can you provide more details / steps around how are you seeing the crash ?

flutter doctor -v

[✓] Flutter (Channel beta, 1.26.0-17.6.pre, on Mac OS X 10.15.4 19E2269
    darwin-x64, locale en-IN)
    • Flutter version 1.26.0-17.6.pre at /Users/dhs/documents/Fluttersdk/flutter
    • Framework revision a29104a69b (19 hours ago), 2021-02-16 09:26:56 -0800
    • Engine revision 21fa8bb99e
    • Dart version 2.12.0 (build 2.12.0-259.12.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
    • Android SDK at /Users/dhs/Library/Android/sdk
    • Platform android-30, build-tools 30.0.0
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[!] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.3, Build version 12C33
    ! CocoaPods 1.9.3 out of date (1.10.0 is recommended).
        CocoaPods is used to retrieve the iOS and macOS platform side's plugin
        code that responds to your plugin usage on the Dart side.
        Without CocoaPods, plugins will not work on iOS or macOS.
        For more info, see https://flutter.dev/platform-plugins
      To upgrade see
      https://guides.cocoapods.org/using/getting-started.html#installation for
      instructions.

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • 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
      1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.53.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.18.1

[✓] Connected device (2 available)
    • sdk gphone x86 arm (mobile) • emulator-5554 • android-x86    • Android 11
      (API 30) (emulator)
    • Chrome (web)                • chrome        • web-javascript • Google
      Chrome 88.0.4324.150

! Doctor found issues in 1 category.

[MaikuB]

@darshankawar the steps I mentioned were all that I did. Your error looks worse because device_info had already been migrated to null safety (see https://github.com/flutter/plugins/blob/master/packages/device_info/device_info/pubspec.yaml). The error you're seeing generally occurs when looks using a plugin that hasn't been migrated to null safety but the app using it has opted in. Are you sure your copy of the plugins repo is up to date?

[MaikuB]

Also noticed you mentioned you updated the plugin's SDK constraints though the steps I mentioned were to update the example's SDK constraints. As the plugin itself has already been migrated to null safety, it doesn't need to have the SDK constraints updated. In my original post, I had posted a link to a fork that can reproduce the problem so that could be cloned and run to see the issue. For convenience, the link is https://github.com/MaikuB/plugins/tree/null_safety_device_info_crash/packages/device_info/device_info. As I'm writing this, it is only one commit ahead of master, where the only change is to update the SDK constraints of the example app for the device_info plugin. The details of that commit can be seen at MaikuB/plugins@569ec0d

[darshankawar]

Thanks @MaikuB for the details. I was able to see the crash using your fork above. Verified on Android 8.1.0 device using latest beta.

flutter doctor -v

[✓] Flutter (Channel beta, 1.26.0-17.6.pre, on Mac OS X 10.15.4 19E2269
    darwin-x64, locale en-IN)
    • Flutter version 1.26.0-17.6.pre at /Users/dhs/documents/Fluttersdk/flutter
    • Framework revision a29104a69b (2 days ago), 2021-02-16 09:26:56 -0800
    • Engine revision 21fa8bb99e
    • Dart version 2.12.0 (build 2.12.0-259.12.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
    • Android SDK at /Users/dhs/Library/Android/sdk
    • Platform android-30, build-tools 30.0.0
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[!] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.3, Build version 12C33
    ! CocoaPods 1.9.3 out of date (1.10.0 is recommended).
        CocoaPods is used to retrieve the iOS and macOS platform side's plugin
        code that responds to your plugin usage on the Dart side.
        Without CocoaPods, plugins will not work on iOS or macOS.
        For more info, see https://flutter.dev/platform-plugins
      To upgrade see
      https://guides.cocoapods.org/using/getting-started.html#installation for
      instructions.

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • 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
      1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.53.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.18.1

[✓] Connected device (2 available)
    • SM A260G (mobile) • 5200763ebcfa861f • android-arm    • Android 8.1.0 (API
      27)
    • Chrome (web)      • chrome           • web-javascript • Google Chrome
      88.0.4324.182

! Doctor found issues in 1 category.