simplify attach addon

addons/xterm-addon-attach/src/AttachAddon.api.ts

@@ -54,7 +54,7 @@ describe('AttachAddon', () => {
     const server = new WebSocket.Server({ port });
     const data = new Uint8Array([102, 111, 111]);
     server.on('connection', socket => socket.send(data));
-    await page.evaluate(`window.term.loadAddon(new window.AttachAddon(new WebSocket('ws://localhost:${port}'), { inputUtf8: true }))`);
+    await page.evaluate(`window.term.loadAddon(new window.AttachAddon(new WebSocket('ws://localhost:${port}')))`);
     assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'foo');
     server.close();
   });

addons/xterm-addon-attach/src/AttachAddon.ts

@@ -9,13 +9,11 @@ import { Terminal, IDisposable, ITerminalAddon } from 'xterm';
 
 interface IAttachOptions {
   bidirectional?: boolean;
-  inputUtf8?: boolean;
 }
 
 export class AttachAddon implements ITerminalAddon {
   private _socket: WebSocket;
   private _bidirectional: boolean;
-  private _utf8: boolean;
   private _disposables: IDisposable[] = [];
 
   constructor(socket: WebSocket, options?: IAttachOptions) {
@@ -23,17 +21,17 @@ export class AttachAddon implements ITerminalAddon {
     // always set binary type to arraybuffer, we do not handle blobs
     this._socket.binaryType = 'arraybuffer';
     this._bidirectional = (options && options.bidirectional === false) ? false : true;
-    this._utf8 = !!(options && options.inputUtf8);
   }
 
   public activate(terminal: Terminal): void {
-    if (this._utf8) {
-      this._disposables.push(addSocketListener(this._socket, 'message',
-        (ev: MessageEvent | Event | CloseEvent) => terminal.writeUtf8(new Uint8Array((ev as any).data as ArrayBuffer))));
-    } else {
-      this._disposables.push(addSocketListener(this._socket, 'message',
-        (ev: MessageEvent | Event | CloseEvent) => terminal.write((ev as any).data as string)));
-    }
+    this._disposables.push(
+      addSocketListener(this._socket, 'message',
+        (ev: MessageEvent | Event | CloseEvent) => {
+          const data: ArrayBuffer | string = (ev as any).data;
+          terminal.write(typeof data === 'string' ? data : new Uint8Array(data));
+        }
+      )
+    );
 
     if (this._bidirectional) {
       this._disposables.push(terminal.onData(data => this._sendData(data)));