🐛 [firebase_analytics] - Web: Unable to load plugin when uBlock is on, doesn't fail gracefully

[bradcypert]

Bug report

Describe the bug
In web browsers with heavy privacy blocking (Chome/Firefox with UBlock, Brave Browser), Firebase Analytics fails to load. Additionally, it bubbles it's error all the way up to the dart engine and, from what I can tell, isn't something I can catch or modify due to it being generated in generated_plugin_registrant. This results in a white page (nothing loads) and a console error on my Flutter web site (https://my.lunajournal.app).

Steps to reproduce

Steps to reproduce the behavior:

1. Go to 'https://my.lunajournal.app' in a browser with ublock (or similar privacy tooling)
2. Open browser web console
3. Observe console error, blank screen

Stacktrace attached:

Uncaught Error: undefined
    V7 main.dart.js:16263
    s async_patch.dart:315
    $2 async_patch.dart:340
    Z async_patch.dart:245
    V7 main.dart:8
    <anonymous> main.dart.js:79056
    <anonymous> main.dart.js:79051
    dartProgram main.dart.js:79054
    <anonymous> main.dart.js:79056
js_helper.dart:1129:36

Expected behavior

Even if analytics fail to load, I'd expect the remainder of the site to be functional. If that isn't possible, I'd expect a way to disable analytics for web builds while keeping them around for iOS and Android.

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Additional context

Add any other context about the problem here.

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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, 1.21.0-9.2.pre, on Mac OS X 10.15.5 19F101, locale en-US)

[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    ! Some Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses
[✓] Xcode - develop for iOS and macOS (Xcode 11.7)
[✓] Chrome - develop for the web
[✓] Android Studio (version 3.6)
[!] IntelliJ IDEA Ultimate Edition (version 2019.2.3)
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
[!] VS Code (version 1.47.3)
    ✗ Flutter extension not installed; install from
      https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter
[✓] Connected device (3 available)

! Doctor found issues in 3 categories.

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Flutter dependencies

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

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Dart SDK 2.10.0-7.3.beta
Flutter SDK 1.21.0-9.2.pre
luna_journal 1.0.0+1

dependencies:
- apple_sign_in 0.1.0 [flutter]
- cloud_firestore 0.13.7 [flutter meta firebase_core cloud_firestore_platform_interface cloud_firestore_web]
- cupertino_icons 0.1.3
- firebase_analytics 5.0.16 [meta flutter firebase_analytics_web firebase_analytics_platform_interface]
- firebase_auth 0.16.1 [meta firebase_core firebase_auth_platform_interface firebase_auth_web flutter]
- firebase_core 0.4.5 [firebase_core_platform_interface flutter meta firebase_core_web]
- fluro 1.6.3 [flutter]
- flutter 0.0.0 [characters collection meta typed_data vector_math sky_engine]
- google_sign_in 4.5.3 [google_sign_in_platform_interface flutter meta google_sign_in_web]
- hive 1.4.4 [meta crypto]
- hive_flutter 0.3.1 [flutter hive path_provider path]
- icons_helper 1.0.4 [flutter font_awesome_flutter flutter_driver]
- provider 4.3.2+1 [flutter nested collection]
- url_launcher 5.5.2 [flutter url_launcher_platform_interface url_launcher_web url_launcher_linux url_launcher_macos]
- zefyr 0.11.0 [flutter collection url_launcher quill_delta notus meta quiver_hashcode]

dev dependencies:
- 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]

transitive dependencies:
- archive 2.0.13 [crypto args path]
- args 1.6.0
- async 2.5.0-nullsafety [collection]
- boolean_selector 2.1.0-nullsafety [source_span string_scanner]
- characters 1.1.0-nullsafety.2
- charcode 1.2.0-nullsafety
- clock 1.1.0-nullsafety
- cloud_firestore_platform_interface 1.1.2 [flutter meta collection firebase_core plugin_platform_interface]
- cloud_firestore_web 0.1.1+2 [flutter flutter_web_plugins firebase http_parser meta firebase_core cloud_firestore_platform_interface js]
- collection 1.15.0-nullsafety.2
- convert 2.1.1 [charcode typed_data]
- crypto 2.1.5 [collection convert typed_data]
- fake_async 1.1.0-nullsafety [clock collection]
- file 5.2.1 [intl meta path]
- firebase 7.3.0 [http http_parser js]
- firebase_analytics_platform_interface 1.0.3 [flutter meta]
- firebase_analytics_web 0.1.1 [flutter flutter_web_plugins firebase firebase_analytics_platform_interface meta]
- firebase_auth_platform_interface 1.1.8 [flutter meta plugin_platform_interface]
- firebase_auth_web 0.1.3+1 [firebase_auth_platform_interface flutter flutter_web_plugins firebase http_parser meta js]
- firebase_core_platform_interface 1.0.4 [flutter meta plugin_platform_interface quiver]
- firebase_core_web 0.1.1+2 [firebase firebase_core_platform_interface flutter flutter_web_plugins meta js]
- flutter_driver 0.0.0 [file json_rpc_2 meta path web_socket_channel vm_service_client webdriver flutter flutter_test fuchsia_remote_debug_protocol archive args async boolean_selector characters charcode clock collection convert crypto fake_async intl matcher platform process pub_semver source_span stack_trace stream_channel string_scanner sync_http term_glyph test_api typed_data vector_math]
- flutter_web_plugins 0.0.0 [flutter characters collection meta typed_data vector_math]
- font_awesome_flutter 8.8.1 [flutter]
- fuchsia_remote_debug_protocol 0.0.0 [json_rpc_2 process web_socket_channel flutter_test flutter_driver archive args async boolean_selector charcode clock collection convert crypto fake_async file intl matcher meta path platform pub_semver source_span stack_trace stream_channel string_scanner sync_http term_glyph test_api typed_data vector_math vm_service_client webdriver]
- google_sign_in_platform_interface 1.1.2 [flutter meta quiver]
- google_sign_in_web 0.9.1+1 [google_sign_in_platform_interface flutter flutter_web_plugins meta js]
- http 0.12.2 [http_parser path pedantic]
- http_parser 3.1.4 [charcode collection source_span string_scanner typed_data]
- intl 0.16.1 [path]
- js 0.6.2
- json_rpc_2 2.2.1 [stack_trace stream_channel]
- matcher 0.12.10-nullsafety [stack_trace]
- meta 1.3.0-nullsafety.2
- nested 0.0.4 [flutter]
- notus 0.1.5 [collection meta quill_delta quiver_hashcode]
- path 1.8.0-nullsafety
- path_provider 1.6.14 [flutter path_provider_platform_interface path_provider_macos path_provider_linux]
- path_provider_linux 0.0.1+2 [path xdg_directories path_provider_platform_interface flutter]
- path_provider_macos 0.0.4+3 [flutter]
- path_provider_platform_interface 1.0.3 [flutter meta platform plugin_platform_interface]
- pedantic 1.9.2 [meta]
- platform 2.2.1
- platform_detect 1.4.0 [meta pub_semver]
- plugin_platform_interface 1.0.2 [meta]
- process 3.0.13 [file intl meta path platform]
- pub_semver 1.4.4 [collection]
- quill_delta 1.0.2 [collection quiver_hashcode]
- quiver 2.1.3 [matcher meta]
- quiver_hashcode 2.0.0
- sky_engine 0.0.99
- source_span 1.8.0-nullsafety [charcode collection path term_glyph]
- stack_trace 1.10.0-nullsafety [path]
- stream_channel 2.1.0-nullsafety [async]
- string_scanner 1.1.0-nullsafety [charcode source_span]
- sync_http 0.2.0
- term_glyph 1.2.0-nullsafety
- test_api 0.2.19-nullsafety [async boolean_selector collection meta path source_span stack_trace stream_channel string_scanner term_glyph matcher]
- typed_data 1.3.0-nullsafety.2 [collection]
- url_launcher_linux 0.0.1+1 [flutter]
- url_launcher_macos 0.0.1+7 [flutter]
- url_launcher_platform_interface 1.0.8 [flutter meta plugin_platform_interface]
- url_launcher_web 0.1.3+1 [url_launcher_platform_interface platform_detect flutter flutter_web_plugins meta]
- vector_math 2.1.0-nullsafety.2
- vm_service_client 0.2.6+2 [async collection json_rpc_2 pub_semver source_span stack_trace stream_channel web_socket_channel]
- web_socket_channel 1.1.0 [async crypto stream_channel]
- webdriver 2.1.2 [archive matcher path stack_trace sync_http]
- xdg_directories 0.1.2 [meta path process]

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[bradcypert]

@TahaTesser I'd be happy to help work on this, but I'm not sure where to start. Any pointers?

[Ehesp]

I'm not sure there's much we can do here until we're able to bundle the Firebase code within the compiled Dart code (currently not do-able). We wrap the https://pub.dev/packages/firebase package, which itself assumes Firebase is available.

Other than that, we could look for the firebase global in the window object and check whether it exists.

[bradcypert]

That makes sense to me. Is it possible to opt out of a plug-in given a build flag? For example, if I'm building for web, ignoring the analytics package would probably be sufficient to get past this.

[bradcypert]

Referencing here for anyone else who stumbles upon this issue: googlearchive/firebase-dart#335