TypeScript generation not supporting map configuration

[kajacx]

When I compile a rust wasi component with cargo component build --release and I run jco on the result with

jco transpile plugin-wasi/target/wasm32-wasi/release/plugin_wasi.wasm --instantiation -o out-dir/

Then the generated TS bindings do not match what the JS actually does in the instantiate function.

Genrated TS bindings:

export interface ImportObject {
  'import-point': {
    default(pnt: Point): Point,
  },
  print: {
    default(msg: string): void,
  },
  'wasi:cli-base/environment': typeof ImportsEnvironment,
  'wasi:cli-base/exit': typeof ImportsExit,
  'wasi:cli-base/preopens': typeof ImportsPreopens,
  'wasi:cli-base/stderr': typeof ImportsStderr,
  'wasi:cli-base/stdin': typeof ImportsStdin,
  'wasi:cli-base/stdout': typeof ImportsStdout,
  'wasi:filesystem/filesystem': typeof ImportsFilesystem,
  'wasi:io/streams': typeof ImportsStreams,
}

Actual JS code:

export async function instantiate(compileCore, imports, instantiateCore = WebAssembly.instantiate) {
  const module0 = compileCore('plugin_wasi.core.wasm');
  const module1 = compileCore('plugin_wasi.core2.wasm');
  const module2 = compileCore('plugin_wasi.core3.wasm');
  const module3 = compileCore('plugin_wasi.core4.wasm');
  
  const { environment, exit: exit$1, preopens, stderr, stdin, stdout } = imports['@bytecodealliance/preview2-shim/cli-base'];
  const { filesystem } = imports['@bytecodealliance/preview2-shim/filesystem'];
  const { streams } = imports['@bytecodealliance/preview2-shim/io'];
  const importPoint = imports['import-point'].default;
  const print = imports.print.default;

The custom imported functions are fine, but the wasi import object does not match.

Edit: jco version 0.9.4

[guybedford]

Try adding the --no-wasi-shim flag. The WASI bindings are automatically mapped using mapping configuration - https://github.com/bytecodealliance/jco/blob/main/src/cmd/transpile.js#L92.

The bug here is that TypeScript output does not yet support the map configuration itself, so whenever using --map typings and JS will be out of sync.

Changing to title to match the issue, but your problem should be resolved with that flag for now.