From 483af7c33cce1688bb7b6f8f981c649278571180 Mon Sep 17 00:00:00 2001
From: Andrew Johnston <apjohnsto@gmail.com>
Date: Sat, 3 Aug 2024 23:49:36 -0700
Subject: [PATCH] fix (worker-eval): fail worker with source when eval = false
 (#13062)

Co-authored-by: Andrew Johnston <andrew@bun.sh>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
---
 src/js/node/worker_threads.ts      | 10 ++++++++--
 test/js/web/workers/worker.test.ts | 27 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/js/node/worker_threads.ts b/src/js/node/worker_threads.ts
index 4de9fe81e8390c..4cd282398f67b4 100644
--- a/src/js/node/worker_threads.ts
+++ b/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);
diff --git a/test/js/web/workers/worker.test.ts b/test/js/web/workers/worker.test.ts
index 48f6d0f63624b1..210b26e8082ba3 100644
--- a/test/js/web/workers/worker.test.ts
+++ b/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");
+  });
+
 });