From 13dd5686e61efc8459af94cc10c7e5395753ad38 Mon Sep 17 00:00:00 2001
From: mertushka <34413473+mertushka@users.noreply.github.com>
Date: Wed, 11 Jun 2025 17:36:02 +0300
Subject: [PATCH 01/14] fix(polyfill)(RTCDataChannel): fix readyState race
 condition and improve typings

---
 src/polyfill/RTCDataChannel.ts | 96 +++++++++++++++++++---------------
 1 file changed, 53 insertions(+), 43 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index 4300361..4e459fe 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -16,8 +16,6 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
   #label: string;
   #protocol: string;
 
-  #closeRequested = false;
-
   // events
   onbufferedamountlow: globalThis.RTCDataChannel['onbufferedamountlow'] = null;
   onclose: globalThis.RTCDataChannel['onclose'] = null;
@@ -49,14 +47,18 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
 
     this.#dataChannel.onClosed(() => {
       // Simulate closing event
-      if (!this.#closeRequested) {
+      if (this.#readyState === 'closed') return;
+
+      if (this.#readyState !== 'closing') {
         this.#readyState = 'closing';
         this.dispatchEvent(new Event('closing'));
       }
 
       setImmediate(() => {
-        this.#readyState = 'closed';
-        this.dispatchEvent(new Event('close'));
+        if (this.#readyState !== 'closed') {
+          this.#readyState = 'closed';
+          this.dispatchEvent(new Event('close'));
+        }
       });
     });
 
@@ -79,32 +81,21 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
 
     this.#dataChannel.onMessage((data) => {
       if (ArrayBuffer.isView(data)) {
-        if (this.binaryType == 'arraybuffer') data = data.buffer;
-        else data = Buffer.from(data.buffer);
+        data =
+          this.binaryType === 'arraybuffer'
+            ? (data.buffer as ArrayBuffer)
+            : Buffer.from(data.buffer);
       }
 
       this.dispatchEvent(new MessageEvent('message', { data }));
     });
 
     // forward events to properties
-    this.addEventListener('message', (e) => {
-      if (this.onmessage) this.onmessage(e as MessageEvent);
-    });
-    this.addEventListener('bufferedamountlow', (e) => {
-      if (this.onbufferedamountlow) this.onbufferedamountlow(e);
-    });
-    this.addEventListener('error', (e) => {
-      if (this.onerror) this.onerror(e as RTCErrorEvent);
-    });
-    this.addEventListener('close', (e) => {
-      if (this.onclose) this.onclose(e);
-    });
-    this.addEventListener('closing', (e) => {
-      if (this.onclosing) this.onclosing(e);
-    });
-    this.addEventListener('open', (e) => {
-      if (this.onopen) this.onopen(e);
-    });
+    this.addEventListener('open', (e) => this.onopen?.(e));
+    this.addEventListener('message', (e) => this.onmessage?.(e as MessageEvent));
+    this.addEventListener('error', (e) => this.onerror?.(e as RTCErrorEvent));
+    this.addEventListener('close', (e) => this.onclose?.(e));
+    this.addEventListener('bufferedamountlow', (e) => this.onbufferedamountlow?.(e));
   }
 
   set binaryType(type) {
@@ -168,37 +159,56 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
     return this.#readyState;
   }
 
-  send(data): void {
-    if (this.#readyState !== 'open') {
+  send(data: string | Blob | ArrayBuffer | ArrayBufferView): void {
+    if (this.#readyState !== 'open' || !this.#dataChannel.isOpen()) {
       throw new exceptions.InvalidStateError(
         "Failed to execute 'send' on 'RTCDataChannel': RTCDataChannel.readyState is not 'open'",
       );
     }
 
-    // Needs network error, type error implemented
-    if (typeof data === 'string') {
-      this.#dataChannel.sendMessage(data);
-    } else if (data instanceof Blob) {
-      data.arrayBuffer().then((ab) => {
+    try {
+      // Needs network error, type error implemented
+      if (typeof data === 'string') {
+        this.#dataChannel.sendMessage(data);
+      } else if (data instanceof Blob) {
+        data.arrayBuffer().then((ab) => {
+          if (process?.versions?.bun) {
+            this.#dataChannel.sendMessageBinary(Buffer.from(ab));
+          } else {
+            this.#dataChannel.sendMessageBinary(new Uint8Array(ab));
+          }
+        });
+      } else if (data instanceof Uint8Array) {
+        this.#dataChannel.sendMessageBinary(data);
+      } else {
         if (process?.versions?.bun) {
-          this.#dataChannel.sendMessageBinary(Buffer.from(ab));
+          this.#dataChannel.sendMessageBinary(Buffer.from(data as ArrayBuffer));
         } else {
-          this.#dataChannel.sendMessageBinary(new Uint8Array(ab));
+          this.#dataChannel.sendMessageBinary(new Uint8Array(data as ArrayBuffer));
         }
-      });
-    } else if (data instanceof Uint8Array) {
-      this.#dataChannel.sendMessageBinary(data);
-    } else {
-      if (process?.versions?.bun) {
-        this.#dataChannel.sendMessageBinary(Buffer.from(data));
-      } else {
-        this.#dataChannel.sendMessageBinary(new Uint8Array(data));
       }
+    } catch (error: any) {
+      if (error?.message?.includes('DataChannel is closed')) {
+        this.#readyState = 'closed';
+        this.dispatchEvent(new Event('close'));
+        throw new exceptions.InvalidStateError(
+          "Failed to execute 'send' on 'RTCDataChannel': RTCDataChannel.send failed because the DataChannel is closed",
+        );
+      }
+      throw error;
     }
   }
 
   close(): void {
-    this.#closeRequested = true;
+    if (this.#readyState === 'closing' || this.#readyState === 'closed') {
+      throw new exceptions.InvalidStateError(
+        "Failed to execute 'close' on 'RTCDataChannel': The DataChannel is already closing or has been closed",
+      );
+    }
+
+    this.#readyState = 'closing';
+    this.dispatchEvent(new Event('closing'));
+
     setImmediate(() => {
       this.#dataChannel.close();
     });

From 6e22bd110dbe6d4f6f8ea1b4922990fc2990b1ae Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Sat, 14 Jun 2025 02:06:33 +0300
Subject: [PATCH 02/14] revert: unstandard closing event

---
 src/polyfill/RTCDataChannel.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index 4e459fe..07871d7 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -95,6 +95,7 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
     this.addEventListener('message', (e) => this.onmessage?.(e as MessageEvent));
     this.addEventListener('error', (e) => this.onerror?.(e as RTCErrorEvent));
     this.addEventListener('close', (e) => this.onclose?.(e));
+    this.addEventListener('closing', (e) => this.onclosing?.(e));
     this.addEventListener('bufferedamountlow', (e) => this.onbufferedamountlow?.(e));
   }
 

From 37e52838192876722e3943bb3d2f876b0a1f19c5 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Sat, 14 Jun 2025 19:37:59 +0300
Subject: [PATCH 03/14] chore: remove unnecessary checks

---
 src/polyfill/RTCDataChannel.ts | 43 +++++++++++++---------------------
 1 file changed, 16 insertions(+), 27 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index 07871d7..d8a403c 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -161,42 +161,31 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
   }
 
   send(data: string | Blob | ArrayBuffer | ArrayBufferView): void {
-    if (this.#readyState !== 'open' || !this.#dataChannel.isOpen()) {
+    if (this.#readyState !== 'open') {
       throw new exceptions.InvalidStateError(
         "Failed to execute 'send' on 'RTCDataChannel': RTCDataChannel.readyState is not 'open'",
       );
     }
 
-    try {
-      // Needs network error, type error implemented
-      if (typeof data === 'string') {
-        this.#dataChannel.sendMessage(data);
-      } else if (data instanceof Blob) {
-        data.arrayBuffer().then((ab) => {
-          if (process?.versions?.bun) {
-            this.#dataChannel.sendMessageBinary(Buffer.from(ab));
-          } else {
-            this.#dataChannel.sendMessageBinary(new Uint8Array(ab));
-          }
-        });
-      } else if (data instanceof Uint8Array) {
-        this.#dataChannel.sendMessageBinary(data);
-      } else {
+    // Needs network error, type error implemented
+    if (typeof data === 'string') {
+      this.#dataChannel.sendMessage(data);
+    } else if (data instanceof Blob) {
+      data.arrayBuffer().then((ab) => {
         if (process?.versions?.bun) {
-          this.#dataChannel.sendMessageBinary(Buffer.from(data as ArrayBuffer));
+          this.#dataChannel.sendMessageBinary(Buffer.from(ab));
         } else {
-          this.#dataChannel.sendMessageBinary(new Uint8Array(data as ArrayBuffer));
+          this.#dataChannel.sendMessageBinary(new Uint8Array(ab));
         }
+      });
+    } else if (data instanceof Uint8Array) {
+      this.#dataChannel.sendMessageBinary(data);
+    } else {
+      if (process?.versions?.bun) {
+        this.#dataChannel.sendMessageBinary(Buffer.from(data));
+      } else {
+        this.#dataChannel.sendMessageBinary(new Uint8Array(data));
       }
-    } catch (error: any) {
-      if (error?.message?.includes('DataChannel is closed')) {
-        this.#readyState = 'closed';
-        this.dispatchEvent(new Event('close'));
-        throw new exceptions.InvalidStateError(
-          "Failed to execute 'send' on 'RTCDataChannel': RTCDataChannel.send failed because the DataChannel is closed",
-        );
-      }
-      throw error;
     }
   }
 

From c62b15c9ab2a1ff301d41081e5530b70ea68726e Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Sat, 14 Jun 2025 19:41:19 +0300
Subject: [PATCH 04/14] fix: close existing datachannels before closing
 peerconnection

---
 src/polyfill/RTCPeerConnection.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/polyfill/RTCPeerConnection.ts b/src/polyfill/RTCPeerConnection.ts
index d71ade6..6aa8fb0 100644
--- a/src/polyfill/RTCPeerConnection.ts
+++ b/src/polyfill/RTCPeerConnection.ts
@@ -354,6 +354,13 @@ export default class RTCPeerConnection extends EventTarget implements globalThis
   }
 
   close(): void {
+    for (const dc of this.#dataChannels) {
+      if (dc.readyState !== 'closed') {
+        dc.close();
+      }
+    }
+    this.#dataChannels.clear();
+
     this.#peerConnection.close();
   }
 

From 05381db77f77c73f48ed9959aad1ddd90b5ca5cf Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Tue, 17 Jun 2025 17:26:42 +0300
Subject: [PATCH 05/14] fix(polyfill): returning instead of throwing on
 closing/closed state

---
 src/polyfill/RTCDataChannel.ts | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index d8a403c..311bd57 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -190,11 +190,7 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
   }
 
   close(): void {
-    if (this.#readyState === 'closing' || this.#readyState === 'closed') {
-      throw new exceptions.InvalidStateError(
-        "Failed to execute 'close' on 'RTCDataChannel': The DataChannel is already closing or has been closed",
-      );
-    }
+    if (this.#readyState === 'closing' || this.#readyState === 'closed') return;
 
     this.#readyState = 'closing';
     this.dispatchEvent(new Event('closing'));

From 5100ad99331402e220380e21c78f1f2fbc7608c2 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Tue, 17 Jun 2025 17:28:52 +0300
Subject: [PATCH 06/14] fix(types): add explicit ArrayBuffer cast for
 sendMessageBinary calls

---
 src/polyfill/RTCDataChannel.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index 311bd57..ba7beaa 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -182,9 +182,9 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
       this.#dataChannel.sendMessageBinary(data);
     } else {
       if (process?.versions?.bun) {
-        this.#dataChannel.sendMessageBinary(Buffer.from(data));
+        this.#dataChannel.sendMessageBinary(Buffer.from(data as ArrayBuffer));
       } else {
-        this.#dataChannel.sendMessageBinary(new Uint8Array(data));
+        this.#dataChannel.sendMessageBinary(new Uint8Array(data as ArrayBuffer));
       }
     }
   }

From 0ec58d203d72a3c7eb28368e6fe43858e22958e4 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 04:36:47 +0300
Subject: [PATCH 07/14] chore: remove unneeded closing check

---
 src/polyfill/RTCDataChannel.ts | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index ba7beaa..c73186e 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -49,11 +49,6 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
       // Simulate closing event
       if (this.#readyState === 'closed') return;
 
-      if (this.#readyState !== 'closing') {
-        this.#readyState = 'closing';
-        this.dispatchEvent(new Event('closing'));
-      }
-
       setImmediate(() => {
         if (this.#readyState !== 'closed') {
           this.#readyState = 'closed';

From ddce92f8459070e0902131061d7dea5d9479bb40 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 04:38:41 +0300
Subject: [PATCH 08/14] fix: also check for closing data channels

---
 src/polyfill/RTCPeerConnection.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/polyfill/RTCPeerConnection.ts b/src/polyfill/RTCPeerConnection.ts
index 6aa8fb0..0c4f331 100644
--- a/src/polyfill/RTCPeerConnection.ts
+++ b/src/polyfill/RTCPeerConnection.ts
@@ -355,11 +355,10 @@ export default class RTCPeerConnection extends EventTarget implements globalThis
 
   close(): void {
     for (const dc of this.#dataChannels) {
-      if (dc.readyState !== 'closed') {
-        dc.close();
+      if (dc.readyState !== 'closed' && dc.readyState !== 'closing') {
+        dc.close(); // Note: This is currently incorrect per the spec, we should set readyState to 'closed' directly without invoking the 'closing' procedure: https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close
       }
     }
-    this.#dataChannels.clear();
 
     this.#peerConnection.close();
   }

From b291be237b8eb48099a1aacba4731c002251f629 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 04:41:32 +0300
Subject: [PATCH 09/14] fix: prevent another race condition window

---
 src/polyfill/RTCDataChannel.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index c73186e..c09ba06 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -191,7 +191,9 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
     this.dispatchEvent(new Event('closing'));
 
     setImmediate(() => {
-      this.#dataChannel.close();
+      if (this.#readyState !== 'closed') {
+        this.#dataChannel.close();
+      }
     });
   }
 }

From 2168c78a282d123df8f0482f6db5f3b93f975ec8 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 04:46:08 +0300
Subject: [PATCH 10/14] fix: dataChannel onClosed race condition

---
 src/polyfill/RTCDataChannel.ts | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index c09ba06..e4dcfdd 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -46,15 +46,10 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
     });
 
     this.#dataChannel.onClosed(() => {
-      // Simulate closing event
       if (this.#readyState === 'closed') return;
 
-      setImmediate(() => {
-        if (this.#readyState !== 'closed') {
-          this.#readyState = 'closed';
-          this.dispatchEvent(new Event('close'));
-        }
-      });
+      this.#readyState = 'closed';
+      this.dispatchEvent(new Event('close'));
     });
 
     this.#dataChannel.onError((msg) => {

From f3c71ec44e50122b94b1e26c735b363f801d8cf1 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 19:47:49 +0300
Subject: [PATCH 11/14] fix: match the spec behaviour

---
 src/polyfill/RTCDataChannel.ts | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index e4dcfdd..5a5180c 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -16,6 +16,8 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
   #label: string;
   #protocol: string;
 
+  #closeRequested = false;
+
   // events
   onbufferedamountlow: globalThis.RTCDataChannel['onbufferedamountlow'] = null;
   onclose: globalThis.RTCDataChannel['onclose'] = null;
@@ -48,8 +50,21 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
     this.#dataChannel.onClosed(() => {
       if (this.#readyState === 'closed') return;
 
-      this.#readyState = 'closed';
-      this.dispatchEvent(new Event('close'));
+      if (!this.#closeRequested) {
+        // if close was not requested, we emit 'closing' before 'close' to match the spec behavior
+        this.#readyState = 'closing';
+        this.dispatchEvent(new Event('closing'));
+      } else {
+        // close was requested, so we skip 'closing' event to match the spec behavior
+        this.#readyState = 'closing';
+      }
+
+      setImmediate(() => {
+        if (this.#readyState !== 'closed') {
+          this.#readyState = 'closed';
+          this.dispatchEvent(new Event('close'));
+        }
+      });
     });
 
     this.#dataChannel.onError((msg) => {
@@ -182,13 +197,11 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
   close(): void {
     if (this.#readyState === 'closing' || this.#readyState === 'closed') return;
 
+    this.#closeRequested = true;
     this.#readyState = 'closing';
-    this.dispatchEvent(new Event('closing'));
 
     setImmediate(() => {
-      if (this.#readyState !== 'closed') {
-        this.#dataChannel.close();
-      }
+      this.#dataChannel.close();
     });
   }
 }

From dc6a887020b4b7becdd3bb8d5e5e78aaa54d7345 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Thu, 19 Jun 2025 20:21:46 +0300
Subject: [PATCH 12/14] chore: remove comment

---
 src/polyfill/RTCPeerConnection.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/polyfill/RTCPeerConnection.ts b/src/polyfill/RTCPeerConnection.ts
index 0c4f331..9c07992 100644
--- a/src/polyfill/RTCPeerConnection.ts
+++ b/src/polyfill/RTCPeerConnection.ts
@@ -356,7 +356,7 @@ export default class RTCPeerConnection extends EventTarget implements globalThis
   close(): void {
     for (const dc of this.#dataChannels) {
       if (dc.readyState !== 'closed' && dc.readyState !== 'closing') {
-        dc.close(); // Note: This is currently incorrect per the spec, we should set readyState to 'closed' directly without invoking the 'closing' procedure: https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close
+        dc.close();
       }
     }
 

From 0081313082036f1b9b7c8c94aec3cccbd302e5aa Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Sat, 21 Jun 2025 22:38:27 +0300
Subject: [PATCH 13/14] fix(RTCPeerConnection): implement spec-compliant abrupt
 data channel close

---
 src/polyfill/RTCPeerConnection.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/polyfill/RTCPeerConnection.ts b/src/polyfill/RTCPeerConnection.ts
index 9c07992..d2fdb66 100644
--- a/src/polyfill/RTCPeerConnection.ts
+++ b/src/polyfill/RTCPeerConnection.ts
@@ -356,7 +356,12 @@ export default class RTCPeerConnection extends EventTarget implements globalThis
   close(): void {
     for (const dc of this.#dataChannels) {
       if (dc.readyState !== 'closed' && dc.readyState !== 'closing') {
-        dc.close();
+        Object.defineProperty(dc, 'readyState', {
+          value: 'closed',
+          writable: false,
+          enumerable: true,
+          configurable: true,
+        });
       }
     }
 

From 9cbbf63ca3446c48ab183b00448beca5d6a29525 Mon Sep 17 00:00:00 2001
From: mertushka <mertushkaonline@gmail.com>
Date: Sat, 21 Jun 2025 22:40:14 +0300
Subject: [PATCH 14/14] fix(RTCDataChannel): improve close event handling logic

---
 src/polyfill/RTCDataChannel.ts | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/polyfill/RTCDataChannel.ts b/src/polyfill/RTCDataChannel.ts
index 5a5180c..b4d2ec3 100644
--- a/src/polyfill/RTCDataChannel.ts
+++ b/src/polyfill/RTCDataChannel.ts
@@ -54,9 +54,6 @@ export default class RTCDataChannel extends EventTarget implements globalThis.RT
         // if close was not requested, we emit 'closing' before 'close' to match the spec behavior
         this.#readyState = 'closing';
         this.dispatchEvent(new Event('closing'));
-      } else {
-        // close was requested, so we skip 'closing' event to match the spec behavior
-        this.#readyState = 'closing';
       }
 
       setImmediate(() => {