Document new behavior of postMesage on VS Code 1.57+

src/vs/vscode.d.ts

@@ -7369,6 +7369,16 @@ declare module 'vscode' {
 		 * background with `retainContextWhenHidden`).
 		 *
 		 * @param message Body of the message. This must be a string or other json serializable object.
+		 *
+		 *   For older versions of vscode, if an `ArrayBuffer` is included in `message`,
+		 *   it will not be serialized properly and will not be received by the webview.
+		 *   Similarly any TypedArrays, such as a `Uint8Array`, will be very inefficiently
+		 *   serialized and will also not be recreated as a typed array inside the webview.
+		 *
+		 *   However if your extension targets vscode 1.57+ in the `engines` field of its
+		 *   `package.json`, any `ArrayBuffer` values that appear in `message` will be more
+		 *   efficiently transferred to the webview and will also be correctly recreated inside
+		 *   of the webview.
 		 */
 		postMessage(message: any): Thenable<boolean>;
 

src/vs/vscode.proposed.d.ts

@@ -3047,27 +3047,6 @@ declare module 'vscode' {
 
 	//#endregion
 
-	//#region https://github.com/microsoft/vscode/issues/115807
-
-	export interface Webview {
-		/**
-		 * @param message A json serializable message to send to the webview.
-		 *
-		 *   For older versions of vscode, if an `ArrayBuffer` is included in `message`,
-		 *   it will not be serialized properly and will not be received by the webview.
-		 *   Similarly any TypedArrays, such as a `Uint8Array`, will be very inefficiently
-		 *   serialized and will also not be recreated as a typed array inside the webview.
-		 *
-		 *   However if your extension targets vscode 1.56+ in the `engines` field of its
-		 *   `package.json` any `ArrayBuffer` values that appear in `message` will be more
-		 *   efficiently transferred to the webview and will also be recreated inside of
-		 *   the webview.
-		 */
-		postMessage(message: any): Thenable<boolean>;
-	}
-
-	//#endregion
-
 	//#region https://github.com/microsoft/vscode/issues/115616 @alexr00
 	export enum PortAutoForwardAction {
 		Notify = 1,