Universal WASM Loader

universal-wasm-loader.js

export const getWasmCode = async (url) => {
  switch (url.protocol) {
    case "file:":
      const assemblyUrl = url.pathname.substr(0, 1) === "/"
        ? url.pathname.substr(1)
        : url.pathname;

      if (globalThis.Deno !== undefined) {
        return Deno.readFile(assemblyUrl);
      }

      if (globalThis.process !== undefined) {
        const fs = await import("node:fs/promises");

        return fs.readFile(assemblyUrl);
      }

      throw new Error(`Unsupported runtime`);

    case "https:":
    case "http:":
      const response = await fetch(url.toString());

      if (!response.ok) {
        throw new Error(
          `Failed to fetch WASM file: ${response.status} ${response.statusText}`,
        );
      }

      return response.arrayBuffer();

    default:
      throw new Error(`Unsupported protocol: ${url.protocol}`);
  }
};

export const getWasmInstance = async (wasmCode) => {
  const imports = {
    __wbindgen_placeholder__: {},
  };

  const module = await WebAssembly.instantiate(wasmCode, imports);

  return module.instance;
};

export const loadWasm = async (url) => {
  const wasmCode = await getWasmCode(url);

  const wasmInstance = await getWasmInstance(wasmCode);

  return wasmInstance.exports;
};