4 files changed, 70 insertions, 5 deletions
diff --git a/Cargo.lock b/Cargo.lock
index 29f02d5c4..cb5bc2f9d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1819,9 +1819,9 @@ dependencies = [
 
 [[package]]
 name = "fastwebsockets"
-version = "0.2.1"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99a248d92ac4e9048a30d147d7897eaaadd0a5230f11982ab7d6935d7d268902"
+checksum = "fcf2f933f24f45831bd66580a8f9394e440f1f5a23806cf0d4d8b6649e1a01e9"
 dependencies = [
  "base64 0.21.0",
  "cc",
diff --git a/cli/tests/unit/websocket_test.ts b/cli/tests/unit/websocket_test.ts
index 948e2add2..997d8f0df 100644
--- a/cli/tests/unit/websocket_test.ts
+++ b/cli/tests/unit/websocket_test.ts
@@ -1,5 +1,11 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
-import { assertEquals, assertThrows, deferred, fail } from "./test_util.ts";
+import {
+  assert,
+  assertEquals,
+  assertThrows,
+  deferred,
+  fail,
+} from "./test_util.ts";
 
 Deno.test({ permissions: "none" }, function websocketPermissionless() {
   assertThrows(
@@ -82,3 +88,46 @@ Deno.test(
     ws.close();
   },
 );
+
+// https://github.com/denoland/deno/issues/18775
+Deno.test({
+  sanitizeOps: false,
+  sanitizeResources: false,
+}, async function websocketDoubleClose() {
+  const promise = deferred();
+
+  const ac = new AbortController();
+  const listeningPromise = deferred();
+
+  const server = Deno.serve({
+    handler: (req) => {
+      const { response, socket } = Deno.upgradeWebSocket(req);
+      let called = false;
+      socket.onopen = () => socket.send("Hello");
+      socket.onmessage = () => {
+        assert(!called);
+        called = true;
+        socket.send("bye");
+        socket.close();
+      };
+      socket.onclose = () => ac.abort();
+      socket.onerror = () => fail();
+      return response;
+    },
+    signal: ac.signal,
+    onListen: () => listeningPromise.resolve(),
+    hostname: "localhost",
+    port: 4247,
+  });
+
+  await listeningPromise;
+
+  const ws = new WebSocket("ws://localhost:4247/");
+  assertEquals(ws.url, "ws://localhost:4247/");
+  ws.onerror = () => fail();
+  ws.onmessage = () => ws.send("bye");
+  ws.onclose = () => {
+    promise.resolve();
+  };
+  await Promise.all([promise, server]);
+});
diff --git a/ext/websocket/Cargo.toml b/ext/websocket/Cargo.toml
index 03cb3076a..a96b6cceb 100644
--- a/ext/websocket/Cargo.toml
+++ b/ext/websocket/Cargo.toml
@@ -16,7 +16,7 @@ path = "lib.rs"
 [dependencies]
 deno_core.workspace = true
 deno_tls.workspace = true
-fastwebsockets = { version = "0.2.1", features = ["upgrade"] }
+fastwebsockets = { version = "0.2.4", features = ["upgrade"] }
 http.workspace = true
 hyper.workspace = true
 serde.workspace = true
diff --git a/ext/websocket/lib.rs b/ext/websocket/lib.rs
index f63191a8e..798856bc1 100644
--- a/ext/websocket/lib.rs
+++ b/ext/websocket/lib.rs
@@ -34,6 +34,7 @@ use std::cell::Cell;
 use std::cell::RefCell;
 use std::convert::TryFrom;
 use std::fmt;
+use std::future::Future;
 use std::path::PathBuf;
 use std::rc::Rc;
 use std::sync::Arc;
@@ -239,7 +240,8 @@ where
     _ => unreachable!(),
   };
 
-  let client = fastwebsockets::handshake::client(request, socket);
+  let client =
+    fastwebsockets::handshake::client(&LocalExecutor, request, socket);
 
   let (stream, response): (WebSocket<Upgraded>, Response<Body>) =
     if let Some(cancel_resource) = cancel_resource {
@@ -533,3 +535,17 @@ pub fn get_network_error_class_name(e: &AnyError) -> Option<&'static str> {
   e.downcast_ref::<DomExceptionNetworkError>()
     .map(|_| "DOMExceptionNetworkError")
 }
+
+// Needed so hyper can use non Send futures
+#[derive(Clone)]
+struct LocalExecutor;
+
+impl<Fut> hyper::rt::Executor<Fut> for LocalExecutor
+where
+  Fut: Future + 'static,
+  Fut::Output: 'static,
+{
+  fn execute(&self, fut: Fut) {
+    tokio::task::spawn_local(fut);
+  }
+}