fix (worker-eval): fail worker with source when eval = false (#13062)

Co-authored-by: Andrew Johnston <[email protected]>
Co-authored-by: Jarred Sumner <[email protected]>

src/js/node/worker_threads.ts

@@ -216,9 +216,15 @@ class Worker extends EventEmitter {
 
     const builtinsGeneratorHatesEval = "ev" + "a" + "l"[0];
     if (options && builtinsGeneratorHatesEval in options) {
+      if (options[builtinsGeneratorHatesEval]) {
+        const blob = new Blob([filename], { type: "" });
+        this.#urlToRevoke = filename = URL.createObjectURL(blob);
+      } else {
+        // if options.eval = false, allow the constructor below to fail, if
+        // we convert the code to a blob, it will succeed.
+        this.#urlToRevoke = filename;
+      }
       delete options[builtinsGeneratorHatesEval];
-      const blob = new Blob([filename], { type: "" });
-      this.#urlToRevoke = filename = URL.createObjectURL(blob);
     }
     try {
       this.#worker = new WebWorker(filename, options);

test/js/web/workers/worker.test.ts

@@ -293,4 +293,31 @@ describe("worker_threads", () => {
     expect(process.argv).toEqual(original_argv);
     expect(process.execArgv).toEqual(original_execArgv);
   });
+
+  test("worker with eval = false fails with code", async () => {
+    let has_error = false;
+    try {
+      const worker = new wt.Worker("console.log('this should not get printed')", { eval: false });
+    } catch (err) {
+      expect(err.constructor.name).toEqual("TypeError");
+      expect(err.message).toMatch(/BuildMessage: ModuleNotFound.+/);
+      has_error = true;
+    }
+    expect(has_error).toBe(true);
+  });
+
+  test("worker with eval = true succeeds with valid code", async () => {
+    let message;
+    const worker = new wt.Worker("postMessage('hello')", { eval: true });
+    worker.on('message', e => {
+      message = e;
+    });
+    const p = new Promise((resolve, reject) => {
+      worker.on('error', reject);
+      worker.on('exit', resolve);
+    })
+    await p;
+    expect(message).toEqual("hello");
+  });
+
 });