Add test case for evalAsync with nested vm operations

Author: kateinoigakukun

packages/npm-packages/ruby-wasm-wasi/src/index.ts

@@ -146,7 +146,7 @@ export class RubyVM {
             "\n" +
             "Please check your call stack and make sure that you are **not** doing any of the following inside the nested Ruby frame:\n" +
             "  1. Switching fibers (e.g. Fiber#resume, Fiber.yield, and Fiber#transfer)\n" +
-            "     Note that JS::Object#await switches fibers internally\n" +
+            "     Note that `evalAsync` JS API switches fibers internally\n" +
             "  2. Raising uncaught exceptions\n" +
             "     Please catch all exceptions inside the nested operation\n" +
             "  3. Calling Continuation APIs\n"

packages/npm-packages/ruby-wasm-wasi/test/init.ts

@@ -14,13 +14,14 @@ const rubyModule = (async () => {
   return await WebAssembly.compile(binary.buffer);
 })();
 
-export const initRubyVM = async () => {
+export const initRubyVM = async ({ suppressStderr } = { suppressStderr: false }) => {
   let preopens = {};
   if (process.env.RUBY_ROOT) {
     preopens["/usr"] = path.join(process.env.RUBY_ROOT, "./usr");
   }
   const wasi = new WASI({
     args: ["ruby.wasm"].concat(process.argv.slice(2)),
+    stderr: suppressStderr ? 0 : 2,
     preopens,
   });
 

packages/npm-packages/ruby-wasm-wasi/test/vm.test.ts

@@ -139,6 +139,40 @@ eval:11:in \`<main>'`);
     }).toThrowError("Ruby APIs that may rewind the VM stack are prohibited");
   });
 
+  test.each([
+    `JS::RubyVM.evalAsync("")`,
+  ])("nested VM rewinding operation should throw fatal error (async)", async (code) => {
+    // Supress bugreport message triggered by the fatal error inside evalAsync
+    const vm = await initRubyVM({ suppressStderr: true });
+    const setVM = vm.eval(`proc { |vm| JS::RubyVM = vm }`);
+    setVM.call("call", vm.wrap(vm));
+
+    // HACK: We need to capture all promises to avoid unhandled promise rejection
+    const promises: Promise<any>[] = []
+    const _Promise = global.Promise
+    const spy = jest.spyOn(global, "Promise")
+      .mockImplementation((future) => {
+        const promise = new _Promise(future)
+        promises.push(promise)
+        return promise
+      })
+
+    vm.evalAsync(code)
+
+    const rejections: Error[] = []
+    for (const promise of promises) {
+      try {
+        await promise
+      } catch (e) {
+        rejections.push(e)
+      }
+    }
+
+    spy.mockReset()
+
+    expect(rejections[0].message).toMatch("Ruby APIs that may rewind the VM stack are prohibited")
+  });
+
   test("caught raise in nested eval is ok", async () => {
     const vm = await initRubyVM();
     const setVM = vm.eval(`proc { |vm| JS::RubyVM = vm }`);