Web (Mock Bridge)

While Yolk is designed for native platforms, you can run and test your business logic in the browser using a Mock Bridge. This is how the Yolk Playground on this site works.

How it works

In a native environment, the Yolk Runtime injects global functions like __yolk_native_Storage into the JavaScript engine. On the web, we can simulate these by registering our own handlers on globalThis.

The TypeScript logic remains identical; it simply calls into the mock implementations instead of native code.

Setup a Mock Bridge

To simulate a native module in the browser, register a function that accepts a method name and a YolkBin encoded buffer:

import { YolkBin } from "@yolk/sdk"
 
type NativeHandler = (method: string, argsBuffer: ArrayBuffer) => Promise<ArrayBuffer>
 
function registerMockModule(name: string, handler: NativeHandler) {
  (globalThis as any)[`__yolk_native_${name}`] = handler
}
 
// Example: Mocking a "Storage" module
registerMockModule("Storage", async (method, argsBuffer) => {
  const args = YolkBin.decode(argsBuffer)
  
  if (method === "getItem") {
    const key = args[0]
    const value = localStorage.getItem(key)
    return YolkBin.encode(value)
  }
  
  return YolkBin.encode(null)
})

Binary Parity

The Mock Bridge uses the exact same YolkBin binary protocol as the iOS, macOS, and Android runtimes. This ensures that:

1. Serialization behavior is identical between web and native.
2. Zero-copy data (like ArrayBuffer) is handled correctly.
3. Type safety is maintained via the generated proxies.

Testing logic

Using the Mock Bridge is the fastest way to develop your app's core logic. You can use standard web development tools, unit tests (Vitest/Jest), and rapid hot-reloading without needing an emulator or a physical device.