uppercase

Uppercase Example

Demonstrates interception of an interface export with string parameters and return values.

Components

• Target: greeter (JavaScript) exports say-hello and say-goodbye via modulewise:examples/greeter
• Advice: uppercaser (Rust) uppercases string return values

WIT

interface greeter {
  say-hello: func(name: string) -> string;
  say-goodbye: func(name: string) -> string;
}

world greeter-world {
  export greeter;
}

Build

./build.sh

1. Generates the interceptor component from the WIT world using cargo run (interceptor CLI)
2. Builds the JavaScript greeter target using jco componentize
3. Builds the Rust uppercaser advice using cargo component
4. Composes all three into composed.wasm using wac plug

Run

./run.sh

Calls say-hello("world") — the greeter returns "Hello world!", the uppercaser advice transforms it to "HELLO WORLD!".