🐛 [firebase_core_web] flutterfire_ignore_scripts and firebase_core is not defined

[mwoelk]

Bug report

Describe the bug
To comply with GDPR we are not allowed to load any scripts from a third party domain such as *.gstatic.com. Because in this case, the IP address of the user which is deemed personal information is handed over to a third party without the users consent.

Because of this, I wanted to use flutterfire_ignore_scripts as described in the setup docs.

I downloaded the js files and added them to my web/index.html.

    <script src="./vendor/firebase-app.js"></script>
    <script src="./vendor/firebase-messaging.js"></script>

I also added the following line before flutter gets loaded.

window.flutterfire_ignore_scripts = ["core", "messaging"];

Now I get an error in the console stating firebase_core is not defined

Steps to reproduce

Steps to reproduce the behavior:

1. Add firebase + firebase messaging to the project
2. download the firebase-app.js and firebase-messaging.js scripts and add them manually to web/index.html
3. Add the window.flutterfire_ignore_scriptsline to the file as well
4. Build and open the web app. Check the console to see the error

Expected behavior

firebase_core should be defined when manually including the scripts.

Flutter doctor

Run flutter doctor and paste the output below:

Click To Expand

Doctor summary (to see all details, run flutter doctor -v):
[!] Flutter (Channel stable, 3.13.5, on macOS 14.2.1 23C71 darwin-x64, locale en-DE)
    ! Warning: `dart` on your path resolves to /usr/local/Cellar/dart/3.0.4/libexec/bin/dart, which is not inside your current Flutter SDK checkout at /Users/woelkmax/fvm/versions/3.13.5. Consider adding /Users/woelkmax/fvm/versions/3.13.5/bin to the front of your path.
[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 15.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2022.3)
[✓] VS Code (version 1.85.1)
[✓] Connected device (4 available)
[✓] Network resources

! Doctor found issues in 1 category.

[danagbemava-nc]

Hi @mwoelk, would it be possible to provide a complete minimal reproducible code sample in a repo that we can clone so that we can investigate this?

I tried to reproduce with the steps outlined above, but I don't see the firebase_core is not defined error (I tested with the firebase_core example app).

Thank you

[mwoelk]

Hi @danagbemava-nc,

Sure. I cloned the repo and modified the firebase_core example app to ignore the scripts and added a copy of https://www.gstatic.com/firebasejs/10.7.2/firebase-app-compat.js into the example (according to the docs - just had to use the *-compat.js version otherwise I get an export not found).

The error message shown in the console is different if you run in debug or release.

In debug (flutter run -d chrome) i get this error when clicking on the Initialize default app-Button:

Uncaught (in promise) Error: [core/not-initialized] Firebase has not been correctly initialized.

Usually this means you've attempted to use a Firebase service before calling `Firebase.initializeApp`.

In release (flutter run --release -d chrome) I get the error:

firebase_core is not defined

[mwoelk]

I guess it's because the dart implementation expects a window.firebase_<package> object that isn't set when just including the script and is otherwise set automatically by the injection script.

[mwoelk]

When I use the following, the previous errors disappear but instead I alway get a Service messaging is not available error. I won't get that error with automatic injection.

It seems like when th files get injected automatically there is something more going on than just importing the files.

<script type="module">
      import * as core from "./vendor/firebase-app.js";
      import * as messaging from "./vendor/firebase-messaging.js";

      window["firebase_core"] = core;
      window["firebase_messaging"] = messaging;

      window.flutterfire_ignore_scripts = ["core", "messaging"];
</script>

[danagbemava-nc]

Hi @mwoelk, thanks for the clarification in #12204 (comment). I was able to see the same error. But it seems like that issue has been resolved(?). When do you get this issue in #12204 (comment)?