2 files changed, 27 insertions, 2 deletions
diff --git a/op_crates/web/02_abort_signal.js b/op_crates/web/02_abort_signal.js
index 908e85ac9..2b51ef1ea 100644
--- a/op_crates/web/02_abort_signal.js
+++ b/op_crates/web/02_abort_signal.js
@@ -5,6 +5,8 @@
   const signalAbort = Symbol("signalAbort");
   const remove = Symbol("remove");
 
+  const illegalConstructorKey = Symbol("illegalConstructorKey");
+
   class AbortSignal extends EventTarget {
     #aborted = false;
     #abortAlgorithms = new Set();
@@ -29,7 +31,10 @@
       this.#abortAlgorithms.delete(algorithm);
     }
 
-    constructor() {
+    constructor(key) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
       super();
       this.onabort = null;
       this.addEventListener("abort", (evt) => {
@@ -50,7 +55,7 @@
   }
 
   class AbortController {
-    #signal = new AbortSignal();
+    #signal = new AbortSignal(illegalConstructorKey);
 
     get signal() {
       return this.#signal;
diff --git a/op_crates/web/abort_controller_test.js b/op_crates/web/abort_controller_test.js
index a2fb12c65..0243c6628 100644
--- a/op_crates/web/abort_controller_test.js
+++ b/op_crates/web/abort_controller_test.js
@@ -9,6 +9,19 @@ function assertEquals(left, right) {
   assert(left === right);
 }
 
+function assertThrows(fn) {
+  let error = null;
+  try {
+    fn();
+  } catch (error_) {
+    error = error_;
+  }
+  if (error == null) {
+    throw new Error("Didn't throw.");
+  }
+  return error;
+}
+
 function basicAbortController() {
   controller = new AbortController();
   assert(controller);
@@ -64,12 +77,19 @@ function controllerHasProperToString() {
   assertEquals(actual, "[object AbortController]");
 }
 
+function abortSignalIllegalConstructor() {
+  const error = assertThrows(() => new AbortSignal());
+  assert(error instanceof TypeError);
+  assertEquals(error.message, "Illegal constructor.");
+}
+
 function main() {
   basicAbortController();
   signalCallsOnabort();
   signalEventListener();
   onlyAbortsOnce();
   controllerHasProperToString();
+  abortSignalIllegalConstructor();
 }
 
 main();