[go_router] Allow users to specify onExit as optional

[hantrungkien]

Related to flutter/flutter#183099

Allow users to specify onExit as optional

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[gemini-code-assist]

Code Review

This pull request introduces an overrideOnExit parameter to TypedGoRoute and TypedRelativeGoRoute. This parameter controls whether the onExit method on the corresponding route data class is invoked. The default is false, which changes the previous behavior where onExit was always called. My review identifies this as a breaking change that should be handled according to semantic versioning. I've also noted the lack of tests for the new functionality and suggested improvements to the naming and documentation for clarity.

[gemini-code-assist]

This change appears to be a breaking change. Previously, onExit on a GoRouteData subclass was always wired up. With this change, it is now opt-in via the overrideOnExit flag, which defaults to false. This means existing code that relies on onExit will silently stop working until overrideOnExit: true is added. According to semantic versioning, this should probably be a major version bump, and the changelog should reflect this with a BREAKING CHANGE notice.

[gemini-code-assist]

The name overrideOnExit is a bit confusing. It seems to imply it's overriding something, but it's actually enabling a feature. A name like enableOnExit or useDataOnExit might be clearer.

Also, the documentation says 'Whether to override the default behavior of GoRoute.onExit...'. The onExit parameter on GoRoute doesn't have a 'default behavior'; it's either provided or it's null.

Perhaps the documentation could be rephrased for clarity. This comment also applies to TypedRelativeGoRoute on lines 575-585.

Suggested change

	/// Whether to override the default behavior of [GoRoute.onExit] to invoke the
	/// [GoRouteData.onExit] method of the route data class.
	///
	/// When `true`, the [GoRouteData.onExit] method will be invoked when
	/// the route is removed from GoRouter's route history.
	///
	/// When `false`, the default behavior is used, which does not invoke
	/// the [GoRouteData.onExit] method.
	///
	/// Defaults to `false`.
	final bool overrideOnExit;
	/// Whether to use the `onExit` callback from the associated
	/// [GoRouteData] class.
	///
	/// When `true`, the [GoRouteData.onExit] method will be invoked when
	/// the route is removed from GoRouter's route history.
	///
	/// When `false` (the default), the [GoRouteData.onExit] method is not
	/// invoked.
	///
	/// Defaults to `false`.
	final bool overrideOnExit;

[hantrungkien]

go_router_builder PR: #11151

[stuartmorgan-g]

Thanks for the contribution! You’ve checked boxes in the PR checklist above that are not reflected in this PR, so I’m assuming this is a work in progress and am marking it as a Draft. Please review the checklist, updating the PR as appropriate, and when the state of the PR as posted reflects the checklist please feel free to mark it as ready for review.

• 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.

[hantrungkien]

@stuartmorgan-g Thank you for your quick response. I’ve added the missing items. Please take a look and review them for me!

[gemini-code-assist]

Code Review

This pull request introduces the overrideOnExit parameter to TypedGoRoute and TypedRelativeGoRoute, allowing users to explicitly control whether the onExit method of route data classes is invoked. The onExit callback in _GoRouteParameters has been made optional to support this. The changes include updates to the CHANGELOG.md and pubspec.yaml files, along with comprehensive test cases for the new functionality. The implementation is clear, well-documented, and correctly tested, adhering to the repository's coding standards.