fix(resource-fetcher): avoid this in static fs field initializer

[danchily2]

Description

ResourceFetcher.fs.readAsString is an async arrow inside a static class-field initializer and relies on this binding to the class. Because the package resolves through the "react-native": "src/index" entry, Metro compiles this TypeScript source with the consuming app's Babel config. Under @react-native/babel-preset with unstable_transformProfile: 'hermes-stable' (or 'hermes-canary'), the async transform hoists the arrow's this capture to module scope:

var _this = this; // module scope!
class ResourceFetcher {
  static fs = { readAsString: /* ... */ _this.getAdapter().readAsString(path) /* ... */ };
}

_this.getAdapter is undefined, so every model load fails with TypeError: undefined is not a function inside LLMController.load, right after the download finishes — on both iOS and Android. The default transform profile compiles it correctly, which is why this only bites apps that opt into the hermes profiles.

Fix: reference the class by name instead of this. One line, no behavior change.

Introduces a breaking change?

• Yes
• No

Type of change

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Documentation update (improves or adds clarity to existing documentation)
• Other (chores, tests, code style improvements etc.)

Tested on

• iOS
• Android

Testing instructions

1. In a bare RN app (RN 0.86, New Architecture) set unstable_transformProfile: 'hermes-stable' on @react-native/babel-preset in babel.config.js.
2. Load any LLM, e.g. useLLM({ model: GEMMA4_E2B }), on a physical device.
3. Without this patch: load fails with TypeError: undefined is not a function after the download completes. With it: the model loads and generates.

Reproducible without a device: run @babel/core on src/utils/ResourceFetcher.ts with the preset above and inspect the output — the var _this = this hoist lands at module scope.

Verified end-to-end on a physical iPhone 16 with GEMMA4_E2B (MLX backend): download → load → generation all work with this patch (applied via yarn patch against 0.9.2).

Screenshots

N/A

Related issues

N/A

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes

A repo-wide sweep found no other this usage inside static-field initializers, so this is the only affected site.

🤖 Generated with Claude Code

[msluszniak]

Thank you for the PR, tested and works correctly