firebase_app_installations: Type '_TypeError' is not a subtype of type 'JSValue' in type cast when using FirebaseInstallations.instance.getId() in Flutter Web with WebAssembly (Wasm)

[max-anders]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

App Installations

Which platforms are affected?

Web

Description

I'm encountering a Type '_TypeError' is not a subtype of type 'JSValue' in type cast error when using FirebaseInstallations.instance.getId() in a Flutter Web app targeting WebAssembly (Wasm). The same code works fine in non-Wasm environments.

Reproducing the issue

• Create a Flutter Web app targeting WebAssembly.
• Call FirebaseInstallations.instance.getId().
• Encounter the error message.

Firebase Core version

3.12.1

Flutter Version

3.29.1

Relevant Log Output

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 3.29.1, on Microsoft Windows [Version 10.0.26100.3194], locale en-US)
[√] Windows Version (11 Famille 64-bit, 24H2, 2009)
[√] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[√] Chrome - develop for the web
[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.9.2)
[√] Android Studio (version 2024.3)
[√] VS Code (version 1.98.0)
[√] Connected device (3 available)
    ! Device emulator-5562 is offline.
[√] Network resources

• No issues found!

Flutter dependencies

Expand Flutter dependencies snippet

Replace this line with the contents of your `flutter pub deps -- --style=compact`.

Additional context and comments

The issue only occurs when targeting WebAssembly (Wasm), and works in regular Flutter Web builds.

[SelaseKay]

Hi @max-anders, thanks for the report. I'm able to reproduce this issue. I'll investigate further.