`TypeError: Invalid byte sequence` in `service_ts` getter during code generation

[q-uint]

Bug

Starting the Vite dev server fails with a TypeError: Invalid byte sequence thrown from the WASM-generated TextDecoder when reading the service_ts output of GenerateResult.

TypeError: Invalid byte sequence
    at decode (unknown)
    at service_ts (.../node_modules/@icp-sdk/bindgen/dist/esm/core/generate/rs/dist/icp-js-bindgen.js:251:14)
    at writeBindings (.../node_modules/@icp-sdk/bindgen/dist/esm/core/generate/index.js:60:36)
    at async generate (.../node_modules/@icp-sdk/bindgen/dist/esm/core/generate/index.js:35:9)
    at async run (.../node_modules/@icp-sdk/bindgen/dist/esm/plugins/vite.js:30:9)
    at async buildStart (.../node_modules/@icp-sdk/bindgen/dist/esm/plugins/vite.js:9:13)

Root cause

The GenerateResult struct exposes service_ts via wasm_bindgen(getter_with_clone). The generated JS getter reads a pointer/length pair from WASM memory and decodes it via TextDecoder("utf-8", { fatal: true }):

get service_ts() {
    const ret = wasm.__wbg_get_generateresult_service_ts(this.__wbg_ptr);
    return getStringFromWasm0(ret[0], ret[1]); // throws TypeError
}

Note: This getter is a wasm-bindgen build artifact in the published package (dist/esm/core/generate/rs/dist/icp-js-bindgen.js), not in the source repo.

The bytes at that location are not valid UTF-8, so the fatal decoder throws instead of silently replacing with U+FFFD. This means either:

• The Rust code generator is producing non-UTF-8 output for certain .did inputs, or
• The returned pointer/length pair is incorrect (e.g. a memory corruption or use-after-free in the WASM allocator)

Environment

• @icp-sdk/bindgen: 0.2.1
• Vite 6.x
• Node.js 22.x

[marc0olo]

fixed via #111, thanks @q-uint 👍