chanora/poc/flutter_rust_bridge_hello

flutter_rust_bridge Hello Spike

Chanora proof-of-concept. Not product code.

Field	Value
PoC name	flutter_rust_bridge_hello (dir kept underscored for Dart-package naming)
PoC plan	docs/architecture/proof-of-concept-plan.md §2
Purpose	Prove the command / result / event DTO boundary between Flutter and Rust
Exit criterion	"Flutter can call Rust and receive event stream data"

Naming note. The PoC plan lists this spike as flutter-rust-bridge-hello. Dart pubspec package names require underscores, so the on-disk directory is flutter_rust_bridge_hello. This is a naming convention, not a scope change.

What it does

API	Direction	Demonstrates
greet(name)	Dart → Rust → Dart (sync)	Typed GreetResult DTO + typed GreetError (Result-style fallible command)
counterStream(count, intervalMs)	Rust → Dart (async stream)	Typed CounterTick event stream with ordered delivery and clean close

The lib/main.dart demo wires both into a Material 3 surface (button + text field + live tick list). This UI is illustrative only — the Chanora Design System belongs to the product Flutter app, not this PoC.

Layout

flutter_rust_bridge_hello/
  rust/                 # Rust crate (cdylib + staticlib)
    src/
      lib.rs            # crate root; declares api + frb_generated
      api/
        mod.rs
        simple.rs       # public API (greet, counter_stream, DTOs)
      frb_generated.rs  # autogenerated; do not edit
    Cargo.toml
  lib/
    main.dart           # demo UI
    src/rust/           # autogenerated Dart bindings; do not edit
  test/
    poc_verification_test.dart   # headless verification (flutter test)
  integration_test/
    simple_test.dart    # same checks, runs under integration_test driver
  flutter_rust_bridge.yaml
  pubspec.yaml
  linux/ android/ ios/ macos/ windows/ web/
  rust_builder/         # cargokit build hook (generated)

Reproduce

Requires Flutter stable (developed against 3.41.9 / Dart 3.11.5), flutter_rust_bridge_codegen 2.12.0, Rust stable (developed against 1.95). Linux desktop toolchain (clang, cmake, ninja, GTK3) for the build path proven here. Network access required for first build (cargo + pub).

# Generate bindings whenever rust/src/api/*.rs changes
flutter_rust_bridge_codegen generate

# Build for Linux desktop (also builds the cdylib via cargokit)
flutter build linux --debug

# Headless verification — exercises the same API the demo UI uses.
LD_LIBRARY_PATH="$PWD/build/linux/x64/debug/bundle/lib:$LD_LIBRARY_PATH" \
    flutter test test/poc_verification_test.dart

# Interactive run (requires a display)
flutter run -d linux

Scope boundaries

• No TeamSpeak / tsclientlib integration (covered by tsclientlib-connect-spike).
• No platform secure storage, SQLite, or audio (separate PoCs).
• No real DTO catalogue, no error taxonomy, no event-key conventions — chanora_bridge will own those per SAD §7.2.
• Only the Linux desktop target has been built and verified. Android, iOS, macOS, Windows are scaffolded by flutter create but unverified here.

Verification log

See VERIFICATION.md in this directory.