Error Handling Across the WASM Boundary
Handle Rust Results, Options, and panics cleanly when they cross into JavaScript using wasm-bindgen.
Errors Need a Bridge
Rust uses Result and Option for errors; JavaScript uses exceptions and null/undefined.
wasm-bindgen bridges these two worlds so failures surface naturally on each side.
Returning Result to JS
A Rust function returning Result<T, JsValue> becomes a JS function that either returns the value or throws.
use wasm_bindgen::prelude::*;
#[wasm_bindgen]
pub fn parse(input: &str) -> Result<i32, JsValue> {
input.parse::<i32>()
.map_err(|e| JsValue::from_str(&e.to_string()))
}All lessons in this course
- Setting up Rust for WebAssembly
- Writing Rust Functions for WASM
- Efficient JS Interop with `wasm-bindgen`
- Error Handling Across the WASM Boundary