Fix AssertionError by adding routeInformationProvider to MaterialApp.router(go_router_builder/example)

[bisor0627]

This PR fixes an AssertionError that occurs when building the MaterialApp widget. The error message is as follows:

════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown building DefaultSelectionStyle:
'package:go_router/src/parser.dart': Failed assertion: line 63 pos 12: 'routeInformation.state != null': is not true.

This error was due to the omission of routeInformationProvider in the MaterialApp.router setup. The original code was:

@override
Widget build(BuildContext context) => MaterialApp.router(
    routeInformationParser: _router.routeInformationParser,
    routerDelegate: _router.routerDelegate,
    title: _appTitle,
);

To fix this error, I added routeInformationProvider: _router.routeInformationProvider, to MaterialApp.router:

@override
Widget build(BuildContext context) => MaterialApp.router(
    routeInformationProvider: _router.routeInformationProvider,
    routeInformationParser: _router.routeInformationParser,
    routerDelegate: _router.routerDelegate,
    title: _appTitle,
);

With this fix, the AssertionError no longer occurs and the MaterialApp builds without issues.

Additionally, I considered changing the MaterialApp.router construction from:

@override
Widget build(BuildContext context) => MaterialApp.router(
    routeInformationProvider: _router.routeInformationProvider,
    routeInformationParser: _router.routeInformationParser,
    routerDelegate: _router.routerDelegate,
    title: _appTitle,
);

to

return MaterialApp.router(
    routerConfig: _router,
);

However, as the lib/main.dart file is already set up with the first MaterialApp.router construction, I decided to maintain its original form.

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[chunhtai]

you can use MaterialApp.router(routerConfig: _router)
directly. It looks like we don't have a test for this example, can you add a simple test like other example just to make sure things can compile?

[chunhtai]

Can you also update other example to use routerConfig as well?

[bisor0627]

Sure, I can add a test for this example to ensure it compiles correctly. I will also update the other examples to use routerConfig. 😀

[bisor0627]

Thank you for your feedback, @chunhtai.

I have updated simple_example.dart and other examples to use routerConfig: _router as you suggested.

Additionally, I've added a test for simple_example.dart. For main.dart, the existing widget_test.dart is already serving as its test, so no additional tests were added.

Please review the changes and let me know if anything else is required.

[chunhtai]

it looks like all_types.dart is not using routerConfig, can you also update that one? beside format, everything else looks good. Thanks for fixing this!

[chunhtai]

we use dart format . on this project directly, this may be causing repro-check failures. Can you run dart format to reformat these files?

[bisor0627]

I have updated the all_types.dart file to use routerConfig as per your request. The changes have been committed and pushed. Thank you for pointing out the parts I missed.

Additionally, I have attached a screenshot of the test code running after changing to _routerConfig.