switch parse buffer to UTF32

src/common/TypedArrayUtils.test.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 import { assert } from 'chai';
-import { fillFallback, concat, utf16ToString } from './TypedArrayUtils';
+import { fillFallback, concat, utf32ToString } from './TypedArrayUtils';
 
 type TypedArray = Uint8Array | Uint16Array | Uint32Array | Uint8ClampedArray
   | Int8Array | Int16Array | Int32Array
@@ -100,6 +100,6 @@ describe('typed array convenience functions', () => {
     for (let i = 0; i < s.length; ++i) {
       data[i] = s.charCodeAt(i);
     }
-    assert.equal(utf16ToString(data), s);
+    assert.equal(utf32ToString(data), s);
   });
 });

src/common/TypedArrayUtils.ts

@@ -1,3 +1,5 @@
+import { stringFromCodePoint } from '../core/input/TextDecoder';
+
 /**
  * Copyright (c) 2018 The xterm.js authors. All rights reserved.
  * @license MIT
@@ -51,11 +53,18 @@ export function concat<T extends TypedArray>(a: T, b: T): T {
 }
 
 /**
- * Convert UTF16 char codes into JS string.
+ * Convert UTF32 char codes into JS string.
  * Note the typed array is not limited to Uint16Array, make sure to align
  * the values to 0-65535 integer for other typed array types, otherwise
  * the conversion will fail.
  */
-export function utf16ToString<T extends TypedArray>(data: T): string {
-  return String.fromCharCode.apply(null, data);
+export function utf32ToString<T extends TypedArray>(data: T): string {
+  if ((String as any).fromCodePoint) {
+    return (String as any).fromCodePoint.apply(null, data);
+  }
+  let result = '';
+  for (let i = 0; i < data.length; ++i) {
+    result += stringFromCodePoint(data[i]);
+  }
+  return result;
 }