🐛 [firebase_messaging] Web app crashes on load when not using firebase config in index.html

Bug report

The Readme for the FlutterFire plugins indicates that you can initialize the FirebaseApp in the Dart code using package:firebase_core methods.

However, firebase_messaging_web crashes on application load when a default app has not been initialised in index.html. From what I can see, this is because the implementation of firebase_messaging_web tries to access the default firebase app when it is constructed as part of plugin registration. This means, that it is necessary to initialize the firebase app twice - in the dart code and in the index.html.

This is actually the same issue, as this one here concerning the analytics plugin.

Steps to reproduce

Steps to reproduce the behavior:

Take a project with Flutter Web enabled and a dependency to the firebase messaging package.
Comment-out the firebaseApp initialization in index.html. The FirebaseApp configuration in main.dart is still present.
Run the app for web flutter run -d chrome.

Apps fails to load with following error:

errors.ts:101 Uncaught (in promise) FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).
    at Object.f [as app] (https://www.gstatic.com/firebasejs/7.22.1/firebase-app.js:1:17054)
    at Object.app$ [as app] (http://localhost:59302/packages/firebase_core_web/src/interop/core.dart.lib.js:42:101)
    at new firebase_messaging_web.FirebaseMessagingWeb.new (http://localhost:59302/packages/firebase_messaging_web/firebase_messaging_web.dart.lib.js:192:64)
    at Function.registerWith (http://localhost:59302/packages/firebase_messaging_web/firebase_messaging_web.dart.lib.js:56:73)
    at Object.registerPlugins (http://localhost:59302/packages/craftsmen_mobile_client/generated_plugin_registrant.dart.lib.js:34:49)
    at main (http://localhost:59302/web_entrypoint.dart.lib.js:44:35)
    at main.next (<anonymous>)
    at runBody (http://localhost:59302/dart_sdk.js:39052:34)
    at Object._async [as async] (http://localhost:59302/dart_sdk.js:39083:7)
    at main$ (http://localhost:59302/web_entrypoint.dart.lib.js:43:18)
    at http://localhost:59302/main_module.bootstrap.js:19:10
    at Array.forEach (<anonymous>)
    at window.$dartRunMain (http://localhost:59302/main_module.bootstrap.js:18:32)
    at <anonymous>:1:8
    at Object.runMain (http://localhost:59302/dwds/src/injected/client.js:8656:21)

Expected behavior

The web app should not crash at this point. The firebase_messaging plugin shouldn't access the firebase instance during plugin registration to avoid a redundant registration of the plugin.

Flutter doctor

Run flutter doctor and paste the output below:

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``` Doctor summary (to see all details, run flutter doctor -v): [√] Flutter (Channel beta, 2.0.0, on Microsoft Windows [Version 10.0.19042.804], locale de-DE) [√] Android toolchain - develop for Android devices (Android SDK version 30.0.3) [√] Chrome - develop for the web [√] Android Studio (version 4.0) [√] VS Code (version 1.53.2) [√] Connected device (2 available) • No issues found! ```

Flutter dependencies

Run flutter pub deps -- --style=compact and paste the output below:

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``` Dart SDK 2.12.0 Flutter SDK 2.0.0 craftsmen_mobile_client 1.7.2+86 dependencies: - amplitude_flutter 2.2.1 [flutter] - badges 1.1.1 [flutter] - bloc 6.0.3 [meta] - cached_network_image 2.3.3 [flutter flutter_cache_manager octo_image] - clipboard 0.1.2+8 [flutter] - collection 1.15.0 - connectivity 3.0.2 [flutter meta connectivity_platform_interface connectivity_macos] - contacts_service 0.3.10 [flutter collection quiver] - country_pickers 1.1.0 [flutter] - csv 4.1.0 - cupertino_icons 0.1.3 - decimal 0.3.5 [rational] - device_info 0.4.2+7 [flutter device_info_platform_interface] - equatable 1.2.5 [collection meta] - excel 1.1.5 [archive xml] - f_logs 1.3.0-alpha-02 [flutter sembast path_provider intl xxtea meta path stack_trace] - file_picker 3.0.0 [flutter flutter_web_plugins flutter_plugin_android_lifecycle plugin_platform_interface] - firebase_core 1.0.0 [firebase_core_platform_interface firebase_core_web flutter meta] - firebase_crashlytics 1.0.0 [firebase_core firebase_core_platform_interface firebase_crashlytics_platform_interface flutter stack_trace] - firebase_messaging 9.0.0 [firebase_core firebase_core_platform_interface firebase_messaging_platform_interface firebase_messaging_web flutter meta] - flutter 0.0.0 [characters collection meta typed_data vector_math sky_engine] - flutter_apns 1.4.1 [flutter firebase_messaging] - flutter_bloc 6.0.5 [flutter bloc provider] - flutter_branch_sdk 1.1.0 [flutter] - flutter_cache_manager 1.4.2 [flutter path_provider uuid http path sqflite pedantic clock file rxdart] - flutter_cupertino_localizations 1.0.1 [flutter flutter_localizations] - flutter_email_sender 4.0.0 [flutter] - flutter_image_compress 0.6.8 [flutter] - flutter_linkify 4.0.2 [flutter linkify] - flutter_local_notifications 4.0.1+2 [flutter flutter_local_notifications_platform_interface platform timezone] - flutter_localizations 0.0.0 [flutter intl characters clock collection meta path typed_data vector_math] - flutter_ringtone_player 2.0.0 [flutter] - flutter_sms 1.1.0 [flutter] - flutter_speed_dial 1.2.5 [flutter] - flutter_styled_toast 1.4.0+1 [flutter flutter_localizations] - flutter_svg 0.20.0-nullsafety.3 [flutter meta path_drawing vector_math xml] - get_it 4.0.4 [async meta] - google_fonts 1.1.2 [flutter http path_provider crypto] - hex 0.1.2 - image_picker 0.7.2 [flutter flutter_plugin_android_lifecycle image_picker_platform_interface] - intl 0.17.0-nullsafety.2 [clock path] - json_annotation 3.0.1 - logger 0.8.3 [io] - logging 0.11.4 - main_thread_started_check 0.0.1 [flutter] - material_design_icons_flutter 4.0.5555 [flutter] - matrix_dart_sdk 0.0.1 [flutter chopper json_annotation uuid jaguar_orm mime_type path_provider logger image universal_platform] - mime_type 0.2.7 - oauth2 1.6.3 [http http_parser crypto] - open_file 3.0.1 [flutter ffi] - package_info 0.4.3 [flutter] - path_provider 2.0.1 [flutter path_provider_platform_interface path_provider_macos path_provider_linux path_provider_windows] - permission_handler 6.0.1 [flutter meta permission_handler_platform_interface] - photo_view 0.10.2 [flutter] - preferences 5.2.1 [flutter shared_preferences] - quiver 2.1.3 [matcher meta] - random_color 1.0.5 [flutter] - scrollable_positioned_list 0.1.8 [flutter meta] - share 2.0.0 [meta mime flutter] - shared_preferences 0.5.7+2 [meta flutter shared_preferences_platform_interface shared_preferences_macos shared_preferences_web] - simple_animations 1.3.12 [flutter] - sqflite 1.3.1+1 [flutter sqflite_common path] - universal_platform 0.1.3 - url_launcher 6.0.2 [flutter url_launcher_platform_interface url_launcher_linux url_launcher_macos url_launcher_windows url_launcher_web] - uuid 2.2.2 [crypto convert] - vibration 1.7.1 [flutter vibration_web] dev dependencies: - build_runner 1.11.1 [args async build build_config build_daemon build_resolvers build_runner_core code_builder collection crypto dart_style glob graphs http_multi_server io js logging meta mime path pedantic pool pub_semver pubspec_parse shelf sh elf_web_socket stack_trace stream_transform timing watcher web_socket_channel yaml] - effective_dart 1.2.4 - flutter_driver 0.0.0 [file meta path vm_service webdriver flutter flutter_test fuchsia_remote_debug_protocol archive args async boolean_selector characters charcode clock collection convert crypto fake_async matcher platform process source_span s tack_trace stream_channel string_scanner sync_http term_glyph test_api typed_data vector_math] - flutter_launcher_icons 0.8.1 [image args yaml path] - flutter_test 0.0.0 [flutter test_api path fake_async clock stack_trace vector_math async boolean_selector characters charcode collection matcher meta source_span stream_channel string_scanner term_glyph typed_data] - jaguar_orm_gen 2.2.30 [jaguar_query jaguar_orm analyzer build logging source_gen meta] - jaguar_query_sqflite 2.2.11 [flutter sqflite jaguar_query] - json_serializable 3.2.3 [analyzer build build_config json_annotation meta path source_gen] - screenshots 2.1.1 [args yaml resource path file archive platform process meta intl tool_mobile] - test 1.16.0-nullsafety.19 [analyzer async boolean_selector coverage http_multi_server io js node_preamble package_config path pedantic pool shelf shelf_packages_handler shelf_static shelf_web_socket source_span stack_trace stream_channel typed_da ta web_socket_channel webkit_inspection_protocol yaml test_api test_core] dependency overrides: - analyzer 0.38.5 [args charcode collection convert crypto front_end glob html kernel meta package_config path pub_semver source_span watcher yaml] - ffi 1.0.0 - file 5.2.1 [intl meta path] - firebase_messaging 9.0.0 [firebase_core firebase_core_platform_interface firebase_messaging_platform_interface firebase_messaging_web flutter meta] - http 0.12.2 [http_parser path pedantic] - intl 0.17.0-nullsafety.2 [clock path] - path_provider 2.0.1 [flutter path_provider_platform_interface path_provider_macos path_provider_linux path_provider_windows] - platform 2.2.1 - plugin_platform_interface 2.0.0 [meta] - process 3.0.13 [file intl meta path platform] - xml 5.0.0-nullsafety.1 [collection meta petitparser] transitive dependencies: - archive 2.0.13 [crypto args path] - args 1.6.0 - async 2.5.0 [collection] - boolean_selector 2.1.0 [source_span string_scanner] - build 1.5.2 [analyzer async convert crypto logging meta path glob] - build_config 0.4.2 [checked_yaml json_annotation meta path pubspec_parse yaml] - build_daemon 2.1.4 [built_collection built_value http_multi_server logging pedantic path pool shelf shelf_web_socket stream_transform watcher web_socket_channel] - build_resolvers 1.4.4 [analyzer build crypto graphs logging meta path package_config pool pub_semver] - build_runner_core 6.0.3 [async build build_config build_resolvers collection convert crypto glob graphs json_annotation logging meta path package_config pedantic pool timing watcher yaml] - built_collection 4.3.2 [collection quiver] - built_value 7.1.0 [built_collection collection fixnum quiver] - characters 1.1.0 - charcode 1.2.0 - checked_yaml 1.0.2 [json_annotation source_span yaml] - chopper 3.0.3 [http meta logging] - clock 1.1.0 - code_builder 3.4.1 [built_collection built_value collection matcher meta] - connectivity_macos 0.2.0 [flutter] - connectivity_platform_interface 2.0.1 [flutter meta plugin_platform_interface] - convert 2.1.1 [charcode typed_data] - coverage 0.15.0 [args logging package_config path source_maps stack_trace vm_service] - crypto 2.1.5 [collection convert typed_data] - csslib 0.16.2 [source_span] - dart_style 1.3.3 [analyzer args path source_span] - device_info_platform_interface 1.0.1 [flutter meta plugin_platform_interface] - fake_async 1.2.0 [clock collection] - firebase_core_platform_interface 4.0.0 [flutter meta plugin_platform_interface] - firebase_core_web 1.0.0 [firebase_core_platform_interface flutter flutter_web_plugins js meta] - firebase_crashlytics_platform_interface 2.0.0 [collection firebase_core flutter meta plugin_platform_interface] - firebase_messaging_platform_interface 2.0.0 [firebase_core flutter meta plugin_platform_interface] - firebase_messaging_web 1.0.0 [firebase_core firebase_core_web firebase_messaging_platform_interface flutter flutter_web_plugins js meta] - fixnum 0.10.11 - flutter_blurhash 0.5.0 [flutter meta] - flutter_local_notifications_platform_interface 2.0.0+1 [flutter plugin_platform_interface] - flutter_plugin_android_lifecycle 2.0.0 [flutter] - flutter_web_plugins 0.0.0 [flutter js characters collection meta typed_data vector_math] - front_end 0.1.27 [kernel package_config meta] - fuchsia_remote_debug_protocol 0.0.0 [process vm_service file meta path platform] - glob 1.2.0 [async collection node_io path pedantic string_scanner] - graphs 0.2.0 - html 0.14.0+3 [csslib source_span] - http_multi_server 2.2.0 [async] - http_parser 3.1.4 [charcode collection source_span string_scanner typed_data] - image 2.1.14 [archive xml] - image_picker_platform_interface 2.0.1 [flutter meta http plugin_platform_interface] - io 0.3.4 [charcode meta path string_scanner] - jaguar_orm 2.2.7 [jaguar_query quiver path meta] - jaguar_query 2.2.9 [meta] - js 0.6.3 - kernel 0.3.27 [args meta] - linkify 3.0.0 - matcher 0.12.10 [stack_trace] - meta 1.3.0 - mime 1.0.0 - nested 0.0.4 [flutter] - node_interop 1.1.1 [js] - node_io 1.1.1 [node_interop path] - node_preamble 1.4.12 - octo_image 0.3.0 [flutter flutter_blurhash] - package_config 1.9.3 [path charcode] - path 1.8.0 - path_drawing 0.5.0-nullsafety.0 [vector_math meta path_parsing flutter] - path_parsing 0.2.0-nullsafety.0 [vector_math meta] - path_provider_linux 2.0.0 [path xdg_directories path_provider_platform_interface flutter] - path_provider_macos 2.0.0 [flutter] - path_provider_platform_interface 2.0.1 [flutter meta platform plugin_platform_interface] - path_provider_windows 2.0.0 [path_provider_platform_interface meta path flutter ffi win32] - pedantic 1.10.0-nullsafety.3 - permission_handler_platform_interface 3.0.0+1 [flutter meta plugin_platform_interface] - petitparser 4.0.0-nullsafety.1 [meta] - pool 1.5.0 [async stack_trace] - provider 4.3.2+2 [flutter nested collection] - pub_cache 0.2.3 [path pub_semver yaml] - pub_semver 1.4.4 [collection] - pubspec_parse 0.1.5 [checked_yaml json_annotation pub_semver yaml] - rational 0.3.8 - resource 2.1.7 [typed_data] - rxdart 0.23.1 - sembast 2.4.7+6 [meta path synchronized] - shared_preferences_macos 0.0.1+10 [shared_preferences_platform_interface flutter] - shared_preferences_platform_interface 1.0.4 [meta flutter] - shared_preferences_web 0.1.2+7 [shared_preferences_platform_interface flutter flutter_web_plugins meta] - shelf 0.7.9 [async collection http_parser path stack_trace stream_channel] - shelf_packages_handler 2.0.0 [path shelf shelf_static] - shelf_static 0.2.9+1 [convert http_parser mime path shelf] - shelf_web_socket 0.2.3 [shelf web_socket_channel stream_channel] - sky_engine 0.0.99 - source_gen 0.9.4+6 [analyzer async build dart_style glob meta path pedantic source_span] - source_map_stack_trace 2.1.0 [path stack_trace source_maps] - source_maps 0.10.10 [source_span] - source_span 1.8.0 [charcode collection path term_glyph] - sqflite_common 1.0.2+1 [synchronized path meta] - stack_trace 1.10.0 [path] - stream_channel 2.1.0 [async] - stream_transform 1.2.0 - string_scanner 1.1.0 [charcode source_span] - sync_http 0.2.0 - synchronized 2.2.0+2 - term_glyph 1.2.0 - test_api 0.2.19 [async boolean_selector collection meta path source_span stack_trace stream_channel string_scanner term_glyph matcher] - test_core 0.3.12-nullsafety.17 [analyzer async args boolean_selector collection coverage glob io meta package_config path pedantic pool source_map_stack_trace source_maps source_span stack_trace stream_channel vm_service yaml matcher test_api] - timezone 0.6.1 [path] - timing 0.1.1+2 [json_annotation] - tool_base 1.9.5+3 [archive file platform process pub_cache] - tool_mobile 1.9.5+1 [tool_base] - typed_data 1.3.0 [collection] - url_launcher_linux 2.0.0 [flutter] - url_launcher_macos 2.0.0 [flutter] - url_launcher_platform_interface 2.0.2 [flutter plugin_platform_interface] - url_launcher_web 2.0.0 [url_launcher_platform_interface meta flutter flutter_web_plugins] - url_launcher_windows 2.0.0 [flutter] - vector_math 2.1.0 - vibration_web 1.6.2 [flutter flutter_web_plugins] - vm_service 5.5.0 [meta] - watcher 0.9.7+15 [async path pedantic] - web_socket_channel 1.1.0 [async crypto stream_channel] - webdriver 2.1.2 [archive matcher path stack_trace sync_http] - webkit_inspection_protocol 0.7.4 [logging] - win32 2.0.0 [ffi] - xdg_directories 0.2.0 [meta path process] - xxtea 2.0.3 - yaml 2.2.1 [charcode collection string_scanner source_span] ```

firebase / flutterfire