[bug] Event payload sent between frontends does not get parsed into an object

Describe the bug

I have two Tauri windows communicating with each other via events on the frontend. I would like to send an object from one window to another. From my understanding, the serialized JSON should be parsed automatically on the receiving end, but instead I'm getting the string representation. This does not seem to be intended behavior.

Possibly related: #2929

Reproduction

In the main window:

type Message = { message: string };

const secondWindow = new WebviewWindow("secondWindow", { /* ... */ });

secondWindow.listen<Message>("message-sent", (e) => console.log(e.payload.message)); // ERROR: `e.payload` is a string

In the secondary window:

const mainWindow = WebviewWindow.getByLabel("main");

mainWindow?.emit("message-sent", { message: "Hello from other window!" });

Expected behavior

e.payload should be an object instead of a string.

Platform and versions

Environment
  › OS: Windows 10.0.22621 X64
  › Webview2: 106.0.1370.52
  › MSVC: 
      - Visual Studio Build Tools 2022
  › Node.js: 16.17.1
  › npm: 8.15.0
  › pnpm: Not installed!
  › yarn: Not installed!
  › rustup: 1.25.1
  › rustc: 1.64.0
  › cargo: 1.64.0
  › Rust toolchain: stable-x86_64-pc-windows-msvc 

Packages
  › @tauri-apps/cli [NPM]: 1.1.1
  › @tauri-apps/api [NPM]: 1.1.0
  › tauri [RUST]: 1.1.1,
  › tauri-build [RUST]: 1.1.1,
  › tao [RUST]: 0.14.0,
  › wry [RUST]: 0.21.1,

App
  › build-type: bundle
  › CSP: unset
  › distDir: ../build
  › devPath: http://localhost:5173/
  › framework: Svelte

App directory structure
  ├─ .git
  ├─ .svelte-kit
  ├─ build
  ├─ node_modules
  ├─ src
  ├─ src-tauri
  └─ static

Stack trace

No response

Additional context

No response

[amrbashir]

I did some investigations and the situation is bad. In JS -> JS/Rust events, payload is serialized to string and then dispatched as string to both JS and Rust listeners but Rust -> JS/Rust will be dispatched to JS as object and as String to Rust. cc @lucasfernog