denoland-deno/tests/node_compat/test/parallel/test-whatwg-encoding-custom-textdecoder-ignorebom.js

// deno-fmt-ignore-file
// deno-lint-ignore-file

// Copyright Joyent and Node contributors. All rights reserved. MIT license.
// Taken from Node 18.12.1
// This file is automatically generated by `tests/node_compat/runner/setup.ts`. Do not modify this file manually.

'use strict';

// From: https://github.com/w3c/web-platform-tests/blob/7f567fa29c/encoding/textdecoder-ignorebom.html
// This is the part that can be run without ICU

require('../common');

const assert = require('assert');

const cases = [
  {
    encoding: 'utf-8',
    bytes: [0xEF, 0xBB, 0xBF, 0x61, 0x62, 0x63]
  },
  {
    encoding: 'utf-16le',
    bytes: [0xFF, 0xFE, 0x61, 0x00, 0x62, 0x00, 0x63, 0x00]
  },
];

cases.forEach((testCase) => {
  const BOM = '\uFEFF';
  let decoder = new TextDecoder(testCase.encoding, { ignoreBOM: true });
  const bytes = new Uint8Array(testCase.bytes);
  assert.strictEqual(decoder.decode(bytes), `${BOM}abc`);
  decoder = new TextDecoder(testCase.encoding, { ignoreBOM: false });
  assert.strictEqual(decoder.decode(bytes), 'abc');
  decoder = new TextDecoder(testCase.encoding);
  assert.strictEqual(decoder.decode(bytes), 'abc');
});