Pre-conf work 2025

src/types/edge-websocket.d.ts

@@ -0,0 +1,48 @@
+/**
+ * Edge WebSocket TypeScript declarations for Next.js Edge runtime.
+ *
+ * Purpose:
+ * - Provide typings for the non-standard `WebSocketPair` constructor available in Edge runtimes.
+ * - Augment the DOM `WebSocket` interface with the `accept()` method (server-side socket).
+ * - Augment `ResponseInit` to allow `{ webSocket: WebSocket }` when returning a 101 Switching Protocols response.
+ *
+ * This file is safe to include in strict mode projects.
+ */
+
+declare global {
+  /**
+   * Edge runtime-specific constructor that yields a pair of WebSockets:
+   * index 0 is the client end, index 1 is the server end.
+   *
+   * Usage:
+   *   const pair = new WebSocketPair();
+   *   const [client, server] = Object.values(pair) as [WebSocket, WebSocket];
+   */
+  // Edge WebSocketPair declaration
+  var WebSocketPair: {
+    new (): { 0: WebSocket; 1: WebSocket };
+    prototype: object;
+  };
+
+  /**
+   * The server-side WebSocket in Edge runtimes exposes `accept()` to finalize the upgrade.
+   * This augments the standard DOM WebSocket interface.
+   */
+  interface WebSocket {
+    /**
+     * Accept the server-side WebSocket before sending/receiving messages.
+     * No-op on client-side sockets.
+     */
+    accept(): void;
+  }
+
+  /**
+   * Next.js Edge runtime allows `webSocket` in ResponseInit when returning a 101 response.
+   * This augments the standard DOM ResponseInit interface.
+   */
+  interface ResponseInit {
+    webSocket?: WebSocket;
+  }
+}
+
+export {};