message: mkdir asyncify test cases
diff: @@ -49,6 +49,11 @@ const getModule = async (name: string) => {
  describe("AsyncWasmInstance", () => {
  beforeAll(async () => {
  const buildDir = path.join(__dirname, "cases", "build");
  +
  + if (!fs.existsSync(buildDir)) {
  + fs.mkdirSync(buildDir);
  + }
  +
  const files = fs.readdirSync(buildDir);
  for (const file of files) {
  