preopen's not really working

[talentlessguy]

Hey, first of all wanted to thank you for this amazing library! It works like a charm with both Node and Deno.

I am experimenting with WASI and I stumbled upon an issue that pre-open is not really working for me. I'm not sure if I'm doing it right, but preopening a current dir didn't help.

It works like fine with wasmtime:

wasmtime --dir=. solar.wasm Counter.sol --emit abi
{"contracts":{"Counter.sol:Counter":{"abi":[{"type":"function","name":"increment","inputs":[],"outputs":[],"stateMutability":"nonpayable"},{"type":"function","name":"number","inputs":[],"outputs":[{"name":"","type":"uint256","internalType":"uint256"}],"stateMutability":"view"},{"type":"function","name":"setNumber","inputs":[{"name":"newNumber","type":"uint256","internalType":"uint256"}],"outputs":[],"stateMutability":"nonpayable"}]}},"version":"0.1.1"}

but doing something similar in JS fails:

import { useAll, WASI } from "uwasi";
import fs from "node:fs/promises";
import process from "node:process";

export const setupSolar = async (args = []) => {
  const wasi = new WASI({
    args,
    preopens: {
      "./": import.meta.dirname,
    },
    features: [
      useAll({})],
  });
  const bytes = await fs.readFile("./solar.wasm");
  const { instance } = await WebAssembly.instantiate(bytes, {
    wasi_snapshot_preview1: wasi.wasiImport,
  });

  return wasi.start(instance);
};

await setupSolar(["-j1", "./Counter.sol", "--emit", "abi"]);

throws:

error: file ./Counter.sol not found


error: aborting due to 1 previous error

I've compiled the source library with the wasip1 target using this method: paradigmxyz/solar#211 (comment)

[andrewmd5]

Currently there is no built-in native file system support. I just contributed a memory file system which you can use roughly like:

const fileSystem = new MemoryFileSystem({
    "/": "",
  });
 fileSystem.addFile("/Counter.sol", fileContents);
useMemoryFS({
        withFileSystem: fileSystem,
        withStdIo: {
          stdout: (str) => {
            if (ArrayBuffer.isView(str)) {
              str = textDecoder.decode(str);
            }
            if (StringBuilder.isMultiline(str)) {
              stdout.append(str);
            } else {
              stdout.appendLine(str);
            }
          },
          stderr: (str) => {
            if (ArrayBuffer.isView(str)) {
              str = textDecoder.decode(str);
            }
            if (StringBuilder.isMultiline(str)) {
              stderr.append(str);
            } else {
              stderr.appendLine(str);
            }
          },
        },
      }),

Full example here.

[talentlessguy]

Where do I import MemoryFileSystem from?