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[CP-stable][flutter_tools] Safely handle non-JSON messages in test stream parsers - #192419
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flutter#192089) When communicating with remote test runners or browsers over test streams or WebSockets, unhandled non-JSON strings (such as dynamic library loading errors or missing snapshot warnings) caused `_ChunkedJsonParser` to throw an unhandled `FormatException` at character 1, crashing the tool. This changes `pipeHarnessToRemote` in `flutter_platform.dart` and `BrowserManager` in `flutter_web_platform.dart` to intercept non-JSON payloads, log warnings and traces, and ignore invalid frames rather than crashing the tool process. Fixes flutter#191898 ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant in-code documentation (doc comments with `///`). - [ ] If this PR introduces a new feature or capability, I created and linked a website documentation issue or PR in [flutter/website] (or verified none is needed). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [flutter/website]: https://github.com/flutter/website [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
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@bkonyi please fill out the PR description above, afterwards the release team will review this request. |
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This pull request was opened from and to a release candidate branch. This should only be done as part of the official Flutter release process. If you are attempting to make a regular contribution to the Flutter project, please close this PR and follow the instructions at Tree Hygiene for detailed instructions on contributing to Flutter. Reviewers: Use caution before merging pull requests to release branches. Ensure the proper procedure has been followed. |
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This pull request updates the test platform and web platform implementations to handle FormatException during JSON decoding of streams from the test runner and browser WebSocket, logging a warning and trace message instead of failing. It also exposes pipeHarnessToRemote for testing and adds a unit test to verify this behavior. I have no feedback to provide.
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@bkonyi. Spoke too soon - could you add a secondary reviewer here as well? |
dcharkes
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walley892
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autosubmit label was removed for flutter/flutter/192419, because - The status or check suite Dashboard Checks has failed. Please fix the issues identified (or deflake) before re-applying this label. |
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Hi @bkonyi, I think there may be a dependency that also needs to be cherry picked. |
…logging When cherry-picking flutter#192089 to the stable release candidate branch `flutter-3.47-candidate.0`, `BrowserManager` in `flutter_web_platform.dart` referenced `_logger` without `_logger` being defined on `BrowserManager` (which was added on `master` in a later Chrome roll PR). This passes `_logger` from `FlutterWebPlatform` through `BrowserManager.start` and stores it on `BrowserManager` so that unexpected non-JSON messages can be logged as intended.
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Should be fixed now! |
dcharkes
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walley892
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Issue Link:
#191898
Impact Description:
Top crash in Flutter 3.47.1 accounting for 245 crashes (11.7% share of top crashes). When a test runner process or browser socket dumps unformatted non-JSON error output (such as dynamic library loading errors or missing snapshot warnings) directly onto the test communication stream or WebSocket,
_ChunkedJsonParserthrows an unhandledFormatException: Unexpected character (at character 1), terminating theflutter testCLI process.Changelog Description:
[flutter/191898] When remote test processes emit plain-text error output on all platforms, prevent flutter_tools from crashing with an unhandled FormatException.
Workaround:
None. Any test execution where a child runner or socket prints plain text instead of JSON fatal crashes the test runner CLI.
Risk:
Test Coverage:
Validation Steps:
Run
flutter test test/general.shard/flutter_platform_test.dartandflutter test test/commands.shard/hermetic/flutter_web_platform_test.dart.Specifically,
pipeHarnessToRemote safely ignores non-JSON string and logs warningvalidates that plain text received over the stream logs a warning/trace without crashing the process, and subsequent valid JSON packets are processed normally.