Merge pull request #11 from kevinushey/feature/uint8array-subarray

support Uint8Array sub-array; tweak utilities

Author: samthor

compile.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env sh
+
+google-closure-compiler               \
+	--compilation_level ADVANCED      \
+	--js_output_file text.min.js      \
+	--language_out ECMASCRIPT5        \
+	--warning_level VERBOSE           \
+	--create_source_map %outname%.map \
+	text.js

package.json

@@ -8,9 +8,11 @@
   "license": "Apache-2.0",
   "devDependencies": {
     "chai": "^4.2.0",
+    "google-closure-compiler": "^20200406.0.0",
     "mocha": "^7.1.0"
   },
   "scripts": {
+    "compile": "./compile.sh",
     "test": "mocha"
   }
 }

suite.js

@@ -38,6 +38,12 @@ function tests(isNative, TextEncoder, TextDecoder) {
         }
       });
 
+      test('subarray', () => {
+        const buffer = new Uint8Array([104, 101, 108, 108, 111]);
+        const array = buffer.subarray(0, 4);
+        assert.equal(dec.decode(array), 'hell');
+      });
+
       test('null in middle', () => {
         const s = 'pad\x00pad';
         const buffer = new Uint8Array([112, 97, 100, 0, 112, 97, 100]);

text.js

@@ -46,7 +46,7 @@ Object.defineProperty(FastTextEncoder.prototype, 'encoding', {value: 'utf-8'});
  * @param {{stream: boolean}=} options
  * @return {!Uint8Array}
  */
-FastTextEncoder.prototype.encode = function(string, options={stream: false}) {
+FastTextEncoder.prototype['encode'] = function(string, options={stream: false}) {
   if (options.stream) {
     throw new Error(`Failed to encode: the 'stream' option is unsupported.`);
   }
@@ -135,19 +135,21 @@ Object.defineProperty(FastTextDecoder.prototype, 'ignoreBOM', {value: false});
  * @param {{stream: boolean}=} options
  * @return {string}
  */
-FastTextDecoder.prototype.decode = function(buffer, options={stream: false}) {
+FastTextDecoder.prototype['decode'] = function(buffer, options={stream: false}) {
   if (options['stream']) {
     throw new Error(`Failed to decode: the 'stream' option is unsupported.`);
   }
 
+  // Accept Uint8Array's as-is.
+  let bytes = buffer;
+
   // Look for ArrayBufferView, which isn't a real type, but basically represents
   // all the valid TypedArray types plus DataView. They all have ".buffer" as
   // an instance of ArrayBuffer.
-  if (buffer.buffer instanceof ArrayBuffer) {
-    buffer = buffer.buffer;
+  if (!(bytes instanceof Uint8Array) && bytes.buffer instanceof ArrayBuffer) {
+    bytes = new Uint8Array(buffer.buffer);
   }
 
-  let bytes = new Uint8Array(buffer);
   let pos = 0;
   let pending = [];
   const chunks = [];