[webview_flutter_wkwebview] Fix crash when calling setOnConsoleMessage multiple times

[rickhohler]

Fixes flutter/flutter#180914

Description

This PR fixes a crash that occurs when setOnConsoleMessage is called multiple times. The WKUserContentController throws an exception if a script message handler with the same name is added more than once. This change ensures that any existing handler is removed before adding the new one.

Tests

• Added testAddScriptMessageHandlerHandlesDuplicates to UserContentControllerProxyAPITests.swift.
• Verified locally with xcodebuild (Exit Code 0).

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under¹.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under¹.
• I updated/added any relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under¹.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

Footnotes

1. Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩² ↩³

[gemini-code-assist]

Code Review

This pull request introduces two separate and valuable improvements. The main change fixes a crash in webview_flutter_wkwebview when setOnConsoleMessage is called multiple times by correctly removing any existing script message handler before adding a new one. This is accompanied by a solid test case. The second change improves error handling in camera_avfoundation by checking the result of AVAssetWriter.startWriting() and propagating errors, also with a corresponding test. Both changes are correct and well-implemented. For future contributions, consider submitting unrelated changes in separate pull requests to improve review focus and maintain a clean commit history.

[stuartmorgan-g]

Please see this comment, which applies here as well.

[stuartmorgan-g]

As a high-level review, this is not consistent with the design of this plugin, which is to use intentionally minimal native wrappers, and implement as much logic as possible in Dart. We would not add remove logic to the add wrapper when removing can be done from Dart.

[gemini-code-assist]

Code Review

This pull request fixes a crash that occurs when setOnConsoleMessage is called multiple times by ensuring any existing script message handler is removed before adding a new one. The change is correct and is accompanied by a new test case that properly verifies the fix. I have one minor suggestion regarding code formatting consistency in the new test.

[rickhohler]

@stuartmorgan-g I've refactored the fix to be purely in Dart as requested. The native changes have been reverted, and the fix is now implemented in webkit_webview_controller.dart with a corresponding regression test. I also restored the PR checklist.

[stuartmorgan-g]

• Added testAddScriptMessageHandlerHandlesDuplicates to UserContentControllerProxyAPITests.swift.
• Verified locally with xcodebuild (Exit Code 0).

The first entry here is no longer accurate, and it's not clear how the second is a test.

• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under1.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under1.

These changes don't appear to have been pushed to the PR.