text: 'use strict';
  const common = require('../common');
  const assert = require('assert');
  const vm = require('vm');
  
  const SlowBuffer = require('buffer').SlowBuffer;
  
  
  const b = Buffer.allocUnsafe(1024);
  assert.strictEqual(1024, b.length);
  
  b[0] = -1;
  assert.strictEqual(b[0], 255);
  
  for (let i = 0; i < 1024; i++) {
    b[i] = i % 256;
  }
  
  for (let i = 0; i < 1024; i++) {
    assert.strictEqual(i % 256, b[i]);
  }
  
  const c = Buffer.allocUnsafe(512);
  assert.strictEqual(512, c.length);
  
  const d = Buffer.from([]);
  assert.strictEqual(0, d.length);
  
  // Test offset properties
  {
    const b = Buffer.alloc(128);
    assert.strictEqual(128, b.length);
    assert.strictEqual(0, b.byteOffset);
    assert.strictEqual(0, b.offset);
  }
  
  // Test creating a Buffer from a Uint32Array
  {
    const ui32 = new Uint32Array(4).fill(42);
    const e = Buffer.from(ui32);
    for (const [index, value] of e.entries()) {
      assert.strictEqual(value, ui32[index]);
    }
  }
  // Test creating a Buffer from a Uint32Array (old constructor)
  {
    const ui32 = new Uint32Array(4).fill(42);
    const e = Buffer(ui32);
    for (const [key, value] of e.entries()) {
      assert.deepStrictEqual(value, ui32[key]);
    }
  }
  
  // Test invalid encoding for Buffer.toString
  assert.throws(() => b.toString('invalid'),
                /Unknown encoding: invalid/);
  // invalid encoding for Buffer.write
  assert.throws(() => b.write('test string', 0, 5, 'invalid'),
                /Unknown encoding: invalid/);
  // unsupported arguments for Buffer.write
  assert.throws(() => b.write('test', 'utf8', 0),
                /is no longer supported/);
  
  
  // try to create 0-length buffers
  assert.doesNotThrow(() => Buffer.from(''));
  assert.doesNotThrow(() => Buffer.from('', 'ascii'));
  assert.doesNotThrow(() => Buffer.from('', 'latin1'));
  assert.doesNotThrow(() => Buffer.alloc(0));
  assert.doesNotThrow(() => Buffer.allocUnsafe(0));
  assert.doesNotThrow(() => new Buffer(''));
  assert.doesNotThrow(() => new Buffer('', 'ascii'));
  assert.doesNotThrow(() => new Buffer('', 'latin1'));
  assert.doesNotThrow(() => new Buffer('', 'binary'));
  assert.doesNotThrow(() => Buffer(0));
  
  // try to write a 0-length string beyond the end of b
  assert.throws(() => b.write('', 2048), RangeError);
  
  // throw when writing to negative offset
  assert.throws(() => b.write('a', -1), RangeError);
  
  // throw when writing past bounds from the pool
  assert.throws(() => b.write('a', 2048), RangeError);
  
  // throw when writing to negative offset
  assert.throws(() => b.write('a', -1), RangeError);
  
  // try to copy 0 bytes worth of data into an empty buffer
  b.copy(Buffer.alloc(0), 0, 0, 0);
  
  // try to copy 0 bytes past the end of the target buffer
  b.copy(Buffer.alloc(0), 1, 1, 1);
  b.copy(Buffer.alloc(1), 1, 1, 1);
  
  // try to copy 0 bytes from past the end of the source buffer
  b.copy(Buffer.alloc(1), 0, 2048, 2048);
  
  // testing for smart defaults and ability to pass string values as offset
  {
    const writeTest = Buffer.from('abcdes');
    writeTest.write('n', 'ascii');
    writeTest.write('o', '1', 'ascii');
    writeTest.write('d', '2', 'ascii');
    writeTest.write('e', 3, 'ascii');
    writeTest.write('j', 4, 'ascii');
    assert.strictEqual(writeTest.toString(), 'nodejs');
  }
  
  // Offset points to the end of the buffer
  // (see https://github.com/nodejs/node/issues/8127).
  assert.doesNotThrow(() => Buffer.alloc(1).write('', 1, 0));
  
  // ASCII slice test
  {
    const asciiString = 'hello world';
  
    for (let i = 0; i < asciiString.length; i++) {
      b[i] = asciiString.charCodeAt(i);
    }
    const asciiSlice = b.toString('ascii', 0, asciiString.length);
    assert.strictEqual(asciiString, asciiSlice);
  }
  
  {
    const asciiString = 'hello world';
    const offset = 100;
  
    assert.strictEqual(asciiString.length, b.write(asciiString, offset, 'ascii'));
    const asciiSlice = b.toString('ascii', offset, offset + asciiString.length);
    assert.strictEqual(asciiString, asciiSlice);
  }
  
  {
    const asciiString = 'hello world';
    const offset = 100;
  
    const sliceA = b.slice(offset, offset + asciiString.length);
    const sliceB = b.slice(offset, offset + asciiString.length);
    for (let i = 0; i < asciiString.length; i++) {
      assert.strictEqual(sliceA[i], sliceB[i]);
    }
  }
  
  // UTF-8 slice test
  {
    const utf8String = '¡hέlló wôrld!';
    const offset = 100;
  
    b.write(utf8String, 0, Buffer.byteLength(utf8String), 'utf8');
    let utf8Slice = b.toString('utf8', 0, Buffer.byteLength(utf8String));
    assert.strictEqual(utf8String, utf8Slice);
  
    assert.strictEqual(Buffer.byteLength(utf8String),
                       b.write(utf8String, offset, 'utf8'));
    utf8Slice = b.toString('utf8', offset,
                           offset + Buffer.byteLength(utf8String));
    assert.strictEqual(utf8String, utf8Slice);
  
    const sliceA = b.slice(offset, offset + Buffer.byteLength(utf8String));
    const sliceB = b.slice(offset, offset + Buffer.byteLength(utf8String));
    for (let i = 0; i < Buffer.byteLength(utf8String); i++) {
      assert.strictEqual(sliceA[i], sliceB[i]);
    }
  }
  
  {
    const slice = b.slice(100, 150);
    assert.strictEqual(50, slice.length);
    for (let i = 0; i < 50; i++) {
      assert.strictEqual(b[100 + i], slice[i]);
    }
  }
  
  {
    // make sure only top level parent propagates from allocPool
    const b = Buffer.allocUnsafe(5);
    const c = b.slice(0, 4);
    const d = c.slice(0, 2);
    assert.strictEqual(b.parent, c.parent);
    assert.strictEqual(b.parent, d.parent);
  }
  
  {
    // also from a non-pooled instance
    const b = Buffer.allocUnsafeSlow(5);
    const c = b.slice(0, 4);
    const d = c.slice(0, 2);
    assert.strictEqual(c.parent, d.parent);
  }
  
  {
    // Bug regression test
    const testValue = '\u00F6\u65E5\u672C\u8A9E'; // ö日本語
    const buffer = Buffer.allocUnsafe(32);
    const size = buffer.write(testValue, 0, 'utf8');
    const slice = buffer.toString('utf8', 0, size);
    assert.strictEqual(slice, testValue);
  }
  
  {
    // Test triple  slice
    const a = Buffer.allocUnsafe(8);
    for (let i = 0; i < 8; i++) a[i] = i;
    const b = a.slice(4, 8);
    assert.strictEqual(4, b[0]);
    assert.strictEqual(5, b[1]);
    assert.strictEqual(6, b[2]);
    assert.strictEqual(7, b[3]);
    const c = b.slice(2, 4);
    assert.strictEqual(6, c[0]);
    assert.strictEqual(7, c[1]);
  }
  
  {
    const d = Buffer.from([23, 42, 255]);
    assert.strictEqual(d.length, 3);
    assert.strictEqual(d[0], 23);
    assert.strictEqual(d[1], 42);
    assert.strictEqual(d[2], 255);
    assert.deepStrictEqual(d, Buffer.from(d));
  }
  
  {
    // Test for proper UTF-8 Encoding
    const e = Buffer.from('über');
    assert.deepStrictEqual(e, Buffer.from([195, 188, 98, 101, 114]));
  }
  
  {
    // Test for proper ascii Encoding, length should be 4
    const f = Buffer.from('über', 'ascii');
    assert.deepStrictEqual(f, Buffer.from([252, 98, 101, 114]));
  }
  
  ['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
    {
      // Test for proper UTF16LE encoding, length should be 8
      const f = Buffer.from('über', encoding);
      assert.deepStrictEqual(f, Buffer.from([252, 0, 98, 0, 101, 0, 114, 0]));
    }
  
    {
      // Length should be 12
      const f = Buffer.from('привет', encoding);
      assert.deepStrictEqual(
        f, Buffer.from([63, 4, 64, 4, 56, 4, 50, 4, 53, 4, 66, 4])
      );
      assert.strictEqual(f.toString(encoding), 'привет');
    }
  
    {
      const f = Buffer.from([0, 0, 0, 0, 0]);
      assert.strictEqual(f.length, 5);
      const size = f.write('あいうえお', encoding);
      assert.strictEqual(size, 4);
      assert.deepStrictEqual(f, Buffer.from([0x42, 0x30, 0x44, 0x30, 0x00]));
    }
  });
  
  {
    const f = Buffer.from('\uD83D\uDC4D', 'utf-16le'); // THUMBS UP SIGN (U+1F44D)
    assert.strictEqual(f.length, 4);
    assert.deepStrictEqual(f, Buffer.from('3DD84DDC', 'hex'));
  }
  
  // Test construction from arrayish object
  {
    const arrayIsh = {0: 0, 1: 1, 2: 2, 3: 3, length: 4};
    let g = Buffer.from(arrayIsh);
    assert.deepStrictEqual(g, Buffer.from([0, 1, 2, 3]));
    const strArrayIsh = {0: '0', 1: '1', 2: '2', 3: '3', length: 4};
    g = Buffer.from(strArrayIsh);
    assert.deepStrictEqual(g, Buffer.from([0, 1, 2, 3]));
  }
  
  //
  // Test toString('base64')
  //
  assert.strictEqual('TWFu', (Buffer.from('Man')).toString('base64'));
  
  {
    // test that regular and URL-safe base64 both work
    const expected = [0xff, 0xff, 0xbe, 0xff, 0xef, 0xbf, 0xfb, 0xef, 0xff];
    assert.deepStrictEqual(Buffer.from('//++/++/++//', 'base64'),
                           Buffer.from(expected));
    assert.deepStrictEqual(Buffer.from('__--_--_--__', 'base64'),
                           Buffer.from(expected));
  }
  
  {
    // big example
    const quote = 'Man is distinguished, not only by his reason, but by this ' +
                  'singular passion from other animals, which is a lust ' +
                  'of the mind, that by a perseverance of delight in the ' +
                  'continued and indefatigable generation of knowledge, ' +
                  'exceeds the short vehemence of any carnal pleasure.';
    const expected = 'TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb' +
                     '24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlci' +
                     'BhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQ' +
                     'gYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGlu' +
                     'dWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZ' +
                     'GdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm' +
                     '5hbCBwbGVhc3VyZS4=';
    assert.strictEqual(expected, (Buffer.from(quote)).toString('base64'));
  
    let b = Buffer.allocUnsafe(1024);
    let bytesWritten = b.write(expected, 0, 'base64');
    assert.strictEqual(quote.length, bytesWritten);
    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
  
    // check that the base64 decoder ignores whitespace
    const expectedWhite = expected.slice(0, 60) + ' \n' +
                          expected.slice(60, 120) + ' \n' +
                          expected.slice(120, 180) + ' \n' +
                          expected.slice(180, 240) + ' \n' +
                          expected.slice(240, 300) + '\n' +
                          expected.slice(300, 360) + '\n';
    b = Buffer.allocUnsafe(1024);
    bytesWritten = b.write(expectedWhite, 0, 'base64');
    assert.strictEqual(quote.length, bytesWritten);
    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
  
    // check that the base64 decoder on the constructor works
    // even in the presence of whitespace.
    b = Buffer.from(expectedWhite, 'base64');
    assert.strictEqual(quote.length, b.length);
    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
  
    // check that the base64 decoder ignores illegal chars
    const expectedIllegal = expected.slice(0, 60) + ' \x80' +
                            expected.slice(60, 120) + ' \xff' +
                            expected.slice(120, 180) + ' \x00' +
                            expected.slice(180, 240) + ' \x98' +
                            expected.slice(240, 300) + '\x03' +
                            expected.slice(300, 360);
    b = Buffer.from(expectedIllegal, 'base64');
    assert.strictEqual(quote.length, b.length);
    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
  }
  
  assert.strictEqual(Buffer.from('', 'base64').toString(), '');
  assert.strictEqual(Buffer.from('K', 'base64').toString(), '');
  
  // multiple-of-4 with padding
  assert.strictEqual(Buffer.from('Kg==', 'base64').toString(), '*');
  assert.strictEqual(Buffer.from('Kio=', 'base64').toString(), '*'.repeat(2));
  assert.strictEqual(Buffer.from('Kioq', 'base64').toString(), '*'.repeat(3));
  assert.strictEqual(Buffer.from('KioqKg==', 'base64').toString(), '*'.repeat(4));
  assert.strictEqual(Buffer.from('KioqKio=', 'base64').toString(), '*'.repeat(5));
  assert.strictEqual(Buffer.from('KioqKioq', 'base64').toString(), '*'.repeat(6));
  assert.strictEqual(Buffer.from('KioqKioqKg==', 'base64').toString(),
                     '*'.repeat(7));
  assert.strictEqual(Buffer.from('KioqKioqKio=', 'base64').toString(),
                     '*'.repeat(8));
  assert.strictEqual(Buffer.from('KioqKioqKioq', 'base64').toString(),
                     '*'.repeat(9));
  assert.strictEqual(Buffer.from('KioqKioqKioqKg==', 'base64').toString(),
                     '*'.repeat(10));
  assert.strictEqual(Buffer.from('KioqKioqKioqKio=', 'base64').toString(),
                     '*'.repeat(11));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioq', 'base64').toString(),
                     '*'.repeat(12));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKg==', 'base64').toString(),
                     '*'.repeat(13));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKio=', 'base64').toString(),
                     '*'.repeat(14));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioq', 'base64').toString(),
                     '*'.repeat(15));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKg==', 'base64').toString(),
                     '*'.repeat(16));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKio=', 'base64').toString(),
                     '*'.repeat(17));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioq', 'base64').toString(),
                     '*'.repeat(18));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKg==',
                                 'base64').toString(),
                     '*'.repeat(19));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKio=',
                                 'base64').toString(),
                     '*'.repeat(20));
  
  // no padding, not a multiple of 4
  assert.strictEqual(Buffer.from('Kg', 'base64').toString(), '*');
  assert.strictEqual(Buffer.from('Kio', 'base64').toString(), '*'.repeat(2));
  assert.strictEqual(Buffer.from('KioqKg', 'base64').toString(), '*'.repeat(4));
  assert.strictEqual(Buffer.from('KioqKio', 'base64').toString(), '*'.repeat(5));
  assert.strictEqual(Buffer.from('KioqKioqKg', 'base64').toString(),
                     '*'.repeat(7));
  assert.strictEqual(Buffer.from('KioqKioqKio', 'base64').toString(),
                     '*'.repeat(8));
  assert.strictEqual(Buffer.from('KioqKioqKioqKg', 'base64').toString(),
                     '*'.repeat(10));
  assert.strictEqual(Buffer.from('KioqKioqKioqKio', 'base64').toString(),
                     '*'.repeat(11));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKg', 'base64').toString(),
                     '*'.repeat(13));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKio', 'base64').toString(),
                     '*'.repeat(14));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKg', 'base64').toString(),
                     '*'.repeat(16));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKio', 'base64').toString(),
                     '*'.repeat(17));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKg',
                                 'base64').toString(),
                     '*'.repeat(19));
  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKio',
                                 'base64').toString(),
                     '*'.repeat(20));
  
  // handle padding graciously, multiple-of-4 or not
  assert.strictEqual(
    Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw==', 'base64').length,
    32
  );
  assert.strictEqual(
    Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw=', 'base64').length,
    32
  );
  assert.strictEqual(
    Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw', 'base64').length,
    32
  );
  assert.strictEqual(
    Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg==', 'base64').length,
    31
  );
  assert.strictEqual(
    Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg=', 'base64').length,
    31
  );
  assert.strictEqual(
    Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg', 'base64').length,
    31
  );
  
  {
  // This string encodes single '.' character in UTF-16
    const dot = Buffer.from('//4uAA==', 'base64');
    assert.strictEqual(dot[0], 0xff);
    assert.strictEqual(dot[1], 0xfe);
    assert.strictEqual(dot[2], 0x2e);
    assert.strictEqual(dot[3], 0x00);
    assert.strictEqual(dot.toString('base64'), '//4uAA==');
  }
  
  {
    // Writing base64 at a position > 0 should not mangle the result.
    //
    // https://github.com/joyent/node/issues/402
    const segments = ['TWFkbmVzcz8h', 'IFRoaXM=', 'IGlz', 'IG5vZGUuanMh'];
    const b = Buffer.allocUnsafe(64);
    let pos = 0;
  
    for (let i = 0; i < segments.length; ++i) {
      pos += b.write(segments[i], pos, 'base64');
    }
    assert.strictEqual(b.toString('latin1', 0, pos),
                       'Madness?! This is node.js!');
  }
  
  // Regression test for https://github.com/nodejs/node/issues/3496.
  assert.strictEqual(Buffer.from('=bad'.repeat(1e4), 'base64').length, 0);
  
  // Regression test for https://github.com/nodejs/node/issues/11987.
  assert.deepStrictEqual(Buffer.from('w0  ', 'base64'),
                         Buffer.from('w0', 'base64'));
  
  // Regression test for https://github.com/nodejs/node/issues/13657.
  assert.deepStrictEqual(Buffer.from(' YWJvcnVtLg', 'base64'),
                         Buffer.from('YWJvcnVtLg', 'base64'));
  
  {
    // Creating buffers larger than pool size.
    const l = Buffer.poolSize + 5;
    const s = 'h'.repeat(l);
    const b = Buffer.from(s);
  
    for (let i = 0; i < l; i++) {
      assert.strictEqual('h'.charCodeAt(0), b[i]);
    }
  
    const sb = b.toString();
    assert.strictEqual(sb.length, s.length);
    assert.strictEqual(sb, s);
  }
  
  {
    // test hex toString
    const hexb = Buffer.allocUnsafe(256);
    for (let i = 0; i < 256; i++) {
      hexb[i] = i;
    }
    const hexStr = hexb.toString('hex');
    assert.strictEqual(hexStr,
                       '000102030405060708090a0b0c0d0e0f' +
                       '101112131415161718191a1b1c1d1e1f' +
                       '202122232425262728292a2b2c2d2e2f' +
                       '303132333435363738393a3b3c3d3e3f' +
                       '404142434445464748494a4b4c4d4e4f' +
                       '505152535455565758595a5b5c5d5e5f' +
                       '606162636465666768696a6b6c6d6e6f' +
                       '707172737475767778797a7b7c7d7e7f' +
                       '808182838485868788898a8b8c8d8e8f' +
                       '909192939495969798999a9b9c9d9e9f' +
                       'a0a1a2a3a4a5a6a7a8a9aaabacadaeaf' +
                       'b0b1b2b3b4b5b6b7b8b9babbbcbdbebf' +
                       'c0c1c2c3c4c5c6c7c8c9cacbcccdcecf' +
                       'd0d1d2d3d4d5d6d7d8d9dadbdcdddedf' +
                       'e0e1e2e3e4e5e6e7e8e9eaebecedeeef' +
                       'f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff');
  
    const hexb2 = Buffer.from(hexStr, 'hex');
    for (let i = 0; i < 256; i++) {
      assert.strictEqual(hexb2[i], hexb[i]);
    }
  }
  
  // Test single hex character is discarded.
  assert.strictEqual(Buffer.from('A', 'hex').length, 0);
  
  // Test that if a trailing character is discarded, rest of string is processed.
  assert.deepStrictEqual(Buffer.from('Abx', 'hex'), Buffer.from('Ab', 'hex'));
  
  // Test single base64 char encodes as 0.
  assert.strictEqual(Buffer.from('A', 'base64').length, 0);
  
  
  {
    // test an invalid slice end.
    const b = Buffer.from([1, 2, 3, 4, 5]);
    const b2 = b.toString('hex', 1, 10000);
    const b3 = b.toString('hex', 1, 5);
    const b4 = b.toString('hex', 1);
    assert.strictEqual(b2, b3);
    assert.strictEqual(b2, b4);
  }
  
  function buildBuffer(data) {
    if (Array.isArray(data)) {
      const buffer = Buffer.allocUnsafe(data.length);
      data.forEach((v, k) => buffer[k] = v);
      return buffer;
    }
    return null;
  }
  
  const x = buildBuffer([0x81, 0xa3, 0x66, 0x6f, 0x6f, 0xa3, 0x62, 0x61, 0x72]);
  
  assert.strictEqual('<Buffer 81 a3 66 6f 6f a3 62 61 72>', x.inspect());
  
  {
    const z = x.slice(4);
    assert.strictEqual(5, z.length);
    assert.strictEqual(0x6f, z[0]);
    assert.strictEqual(0xa3, z[1]);
    assert.strictEqual(0x62, z[2]);
    assert.strictEqual(0x61, z[3]);
    assert.strictEqual(0x72, z[4]);
  }
  
  {
    const z = x.slice(0);
    assert.strictEqual(z.length, x.length);
  }
  
  {
    const z = x.slice(0, 4);
    assert.strictEqual(4, z.length);
    assert.strictEqual(0x81, z[0]);
    assert.strictEqual(0xa3, z[1]);
  }
  
  {
    const z = x.slice(0, 9);
    assert.strictEqual(9, z.length);
  }
  
  {
    const z = x.slice(1, 4);
    assert.strictEqual(3, z.length);
    assert.strictEqual(0xa3, z[0]);
  }
  
  {
    const z = x.slice(2, 4);
    assert.strictEqual(2, z.length);
    assert.strictEqual(0x66, z[0]);
    assert.strictEqual(0x6f, z[1]);
  }
  
  ['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
    const b = Buffer.allocUnsafe(10);
    b.write('あいうえお', encoding);
    assert.strictEqual(b.toString(encoding), 'あいうえお');
  });
  
  ['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
    const b = Buffer.allocUnsafe(11);
    b.write('あいうえお', 1, encoding);
    assert.strictEqual(b.toString(encoding, 1), 'あいうえお');
  });
  
  {
    // latin1 encoding should write only one byte per character.
    const b = Buffer.from([0xde, 0xad, 0xbe, 0xef]);
    let s = String.fromCharCode(0xffff);
    b.write(s, 0, 'latin1');
    assert.strictEqual(0xff, b[0]);
    assert.strictEqual(0xad, b[1]);
    assert.strictEqual(0xbe, b[2]);
    assert.strictEqual(0xef, b[3]);
    s = String.fromCharCode(0xaaee);
    b.write(s, 0, 'latin1');
    assert.strictEqual(0xee, b[0]);
    assert.strictEqual(0xad, b[1]);
    assert.strictEqual(0xbe, b[2]);
    assert.strictEqual(0xef, b[3]);
  }
  
  {
    // Binary encoding should write only one byte per character.
    const b = Buffer.from([0xde, 0xad, 0xbe, 0xef]);
    let s = String.fromCharCode(0xffff);
    b.write(s, 0, 'latin1');
    assert.strictEqual(0xff, b[0]);
    assert.strictEqual(0xad, b[1]);
    assert.strictEqual(0xbe, b[2]);
    assert.strictEqual(0xef, b[3]);
    s = String.fromCharCode(0xaaee);
    b.write(s, 0, 'latin1');
    assert.strictEqual(0xee, b[0]);
    assert.strictEqual(0xad, b[1]);
    assert.strictEqual(0xbe, b[2]);
    assert.strictEqual(0xef, b[3]);
  }
  
  {
    // #1210 Test UTF-8 string includes null character
    let buf = Buffer.from('\0');
    assert.strictEqual(buf.length, 1);
    buf = Buffer.from('\0\0');
    assert.strictEqual(buf.length, 2);
  }
  
  {
    const buf = Buffer.allocUnsafe(2);
    assert.strictEqual(buf.write(''), 0); //0bytes
    assert.strictEqual(buf.write('\0'), 1); // 1byte (v8 adds null terminator)
    assert.strictEqual(buf.write('a\0'), 2); // 1byte * 2
    assert.strictEqual(buf.write('あ'), 0); // 3bytes
    assert.strictEqual(buf.write('\0あ'), 1); // 1byte + 3bytes
    assert.strictEqual(buf.write('\0\0あ'), 2); // 1byte * 2 + 3bytes
  }
  
  {
    const buf = Buffer.allocUnsafe(10);
    assert.strictEqual(buf.write('あいう'), 9); // 3bytes * 3 (v8 adds null term.)
    assert.strictEqual(buf.write('あいう\0'), 10); // 3bytes * 3 + 1byte
  }
  
  {
    // #243 Test write() with maxLength
    const buf = Buffer.allocUnsafe(4);
    buf.fill(0xFF);
    assert.strictEqual(buf.write('abcd', 1, 2, 'utf8'), 2);
    assert.strictEqual(buf[0], 0xFF);
    assert.strictEqual(buf[1], 0x61);
    assert.strictEqual(buf[2], 0x62);
    assert.strictEqual(buf[3], 0xFF);
  
    buf.fill(0xFF);
    assert.strictEqual(buf.write('abcd', 1, 4), 3);
    assert.strictEqual(buf[0], 0xFF);
    assert.strictEqual(buf[1], 0x61);
    assert.strictEqual(buf[2], 0x62);
    assert.strictEqual(buf[3], 0x63);
  
    buf.fill(0xFF);
    assert.strictEqual(buf.write('abcd', 1, 2, 'utf8'), 2);
    assert.strictEqual(buf[0], 0xFF);
    assert.strictEqual(buf[1], 0x61);
    assert.strictEqual(buf[2], 0x62);
    assert.strictEqual(buf[3], 0xFF);
  
    buf.fill(0xFF);
    assert.strictEqual(buf.write('abcdef', 1, 2, 'hex'), 2);
    assert.strictEqual(buf[0], 0xFF);
    assert.strictEqual(buf[1], 0xAB);
    assert.strictEqual(buf[2], 0xCD);
    assert.strictEqual(buf[3], 0xFF);
  
    ['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
      buf.fill(0xFF);
      assert.strictEqual(buf.write('abcd', 0, 2, encoding), 2);
      assert.strictEqual(buf[0], 0x61);
      assert.strictEqual(buf[1], 0x00);
      assert.strictEqual(buf[2], 0xFF);
      assert.strictEqual(buf[3], 0xFF);
    });
  }
  
  {
    // test offset returns are correct
    const b = Buffer.allocUnsafe(16);
    assert.strictEqual(4, b.writeUInt32LE(0, 0));
    assert.strictEqual(6, b.writeUInt16LE(0, 4));
    assert.strictEqual(7, b.writeUInt8(0, 6));
    assert.strictEqual(8, b.writeInt8(0, 7));
    assert.strictEqual(16, b.writeDoubleLE(0, 8));
  }
  
  {
    // test unmatched surrogates not producing invalid utf8 output
    // ef bf bd = utf-8 representation of unicode replacement character
    // see https://codereview.chromium.org/121173009/
    const buf = Buffer.from('ab\ud800cd', 'utf8');
    assert.strictEqual(buf[0], 0x61);
    assert.strictEqual(buf[1], 0x62);
    assert.strictEqual(buf[2], 0xef);
    assert.strictEqual(buf[3], 0xbf);
    assert.strictEqual(buf[4], 0xbd);
    assert.strictEqual(buf[5], 0x63);
    assert.strictEqual(buf[6], 0x64);
  }
  
  {
    // test for buffer overrun
    const buf = Buffer.from([0, 0, 0, 0, 0]); // length: 5
    const sub = buf.slice(0, 4);         // length: 4
    assert.strictEqual(sub.write('12345', 'latin1'), 4);
    assert.strictEqual(buf[4], 0);
    assert.strictEqual(sub.write('12345', 'binary'), 4);
    assert.strictEqual(buf[4], 0);
  }
  
  {
    // test alloc with fill option
    const buf = Buffer.alloc(5, '800A', 'hex');
    assert.strictEqual(buf[0], 128);
    assert.strictEqual(buf[1], 10);
    assert.strictEqual(buf[2], 128);
    assert.strictEqual(buf[3], 10);
    assert.strictEqual(buf[4], 128);
  }
  
  
  // Check for fractional length args, junk length args, etc.
  // https://github.com/joyent/node/issues/1758
  
  // Call .fill() first, stops valgrind warning about uninitialized memory reads.
  Buffer.allocUnsafe(3.3).fill().toString();
  // throws bad argument error in commit 43cb4ec
  Buffer.alloc(3.3).fill().toString();
  assert.strictEqual(Buffer.allocUnsafe(NaN).length, 0);
  assert.strictEqual(Buffer.allocUnsafe(3.3).length, 3);
  assert.strictEqual(Buffer.from({length: 3.3}).length, 3);
  assert.strictEqual(Buffer.from({length: 'BAM'}).length, 0);
  
  // Make sure that strings are not coerced to numbers.
  assert.strictEqual(Buffer.from('99').length, 2);
  assert.strictEqual(Buffer.from('13.37').length, 5);
  
  // Ensure that the length argument is respected.
  ['ascii', 'utf8', 'hex', 'base64', 'latin1', 'binary'].forEach((enc) => {
    assert.strictEqual(Buffer.allocUnsafe(1).write('aaaaaa', 0, 1, enc), 1);
  });
  
  {
    // Regression test, guard against buffer overrun in the base64 decoder.
    const a = Buffer.allocUnsafe(3);
    const b = Buffer.from('xxx');
    a.write('aaaaaaaa', 'base64');
    assert.strictEqual(b.toString(), 'xxx');
  }
  
  // issue GH-3416
  Buffer.from(Buffer.allocUnsafe(0), 0, 0);
  
  // issue GH-5587
  assert.throws(() => Buffer.alloc(8).writeFloatLE(0, 5), RangeError);
  assert.throws(() => Buffer.alloc(16).writeDoubleLE(0, 9), RangeError);
  
  // attempt to overflow buffers, similar to previous bug in array buffers
  assert.throws(() => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
                RangeError);
  assert.throws(() => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
                RangeError);
  
  
  // ensure negative values can't get past offset
  assert.throws(() => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1), RangeError);
  assert.throws(() => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1), RangeError);
  
  
  // test for common write(U)IntLE/BE
  {
    let buf = Buffer.allocUnsafe(3);
    buf.writeUIntLE(0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x56, 0x34, 0x12]);
    assert.strictEqual(buf.readUIntLE(0, 3), 0x123456);
  
    buf.fill(0xFF);
    buf.writeUIntBE(0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56]);
    assert.strictEqual(buf.readUIntBE(0, 3), 0x123456);
  
    buf.fill(0xFF);
    buf.writeIntLE(0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x56, 0x34, 0x12]);
    assert.strictEqual(buf.readIntLE(0, 3), 0x123456);
  
    buf.fill(0xFF);
    buf.writeIntBE(0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56]);
    assert.strictEqual(buf.readIntBE(0, 3), 0x123456);
  
    buf.fill(0xFF);
    buf.writeIntLE(-0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0xaa, 0xcb, 0xed]);
    assert.strictEqual(buf.readIntLE(0, 3), -0x123456);
  
    buf.fill(0xFF);
    buf.writeIntBE(-0x123456, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcb, 0xaa]);
    assert.strictEqual(buf.readIntBE(0, 3), -0x123456);
  
    buf.fill(0xFF);
    buf.writeIntLE(-0x123400, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x00, 0xcc, 0xed]);
    assert.strictEqual(buf.readIntLE(0, 3), -0x123400);
  
    buf.fill(0xFF);
    buf.writeIntBE(-0x123400, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcc, 0x00]);
    assert.strictEqual(buf.readIntBE(0, 3), -0x123400);
  
    buf.fill(0xFF);
    buf.writeIntLE(-0x120000, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0x00, 0x00, 0xee]);
    assert.strictEqual(buf.readIntLE(0, 3), -0x120000);
  
    buf.fill(0xFF);
    buf.writeIntBE(-0x120000, 0, 3);
    assert.deepStrictEqual(buf.toJSON().data, [0xee, 0x00, 0x00]);
    assert.strictEqual(buf.readIntBE(0, 3), -0x120000);
  
    buf = Buffer.allocUnsafe(5);
    buf.writeUIntLE(0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x90, 0x78, 0x56, 0x34, 0x12]);
    assert.strictEqual(buf.readUIntLE(0, 5), 0x1234567890);
  
    buf.fill(0xFF);
    buf.writeUIntBE(0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56, 0x78, 0x90]);
    assert.strictEqual(buf.readUIntBE(0, 5), 0x1234567890);
  
    buf.fill(0xFF);
    buf.writeIntLE(0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x90, 0x78, 0x56, 0x34, 0x12]);
    assert.strictEqual(buf.readIntLE(0, 5), 0x1234567890);
  
    buf.fill(0xFF);
    buf.writeIntBE(0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56, 0x78, 0x90]);
    assert.strictEqual(buf.readIntBE(0, 5), 0x1234567890);
  
    buf.fill(0xFF);
    buf.writeIntLE(-0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x70, 0x87, 0xa9, 0xcb, 0xed]);
    assert.strictEqual(buf.readIntLE(0, 5), -0x1234567890);
  
    buf.fill(0xFF);
    buf.writeIntBE(-0x1234567890, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcb, 0xa9, 0x87, 0x70]);
    assert.strictEqual(buf.readIntBE(0, 5), -0x1234567890);
  
    buf.fill(0xFF);
    buf.writeIntLE(-0x0012000000, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0x00, 0x00, 0x00, 0xee, 0xff]);
    assert.strictEqual(buf.readIntLE(0, 5), -0x0012000000);
  
    buf.fill(0xFF);
    buf.writeIntBE(-0x0012000000, 0, 5);
    assert.deepStrictEqual(buf.toJSON().data, [0xff, 0xee, 0x00, 0x00, 0x00]);
    assert.strictEqual(buf.readIntBE(0, 5), -0x0012000000);
  }
  
  // Regression test for #5482: should throw but not assert in C++ land.
  assert.throws(() => Buffer.from('', 'buffer'),
                /^TypeError: "encoding" must be a valid string encoding$/);
  
  // Regression test for #6111. Constructing a buffer from another buffer
  // should a) work, and b) not corrupt the source buffer.
  {
    const a = [...Array(128).keys()]; // [0, 1, 2, 3, ... 126, 127]
    const b = Buffer.from(a);
    const c = Buffer.from(b);
    assert.strictEqual(b.length, a.length);
    assert.strictEqual(c.length, a.length);
    for (let i = 0, k = a.length; i < k; ++i) {
      assert.strictEqual(a[i], i);
      assert.strictEqual(b[i], i);
      assert.strictEqual(c[i], i);
    }
  }
  
  if (common.hasCrypto) {
    // Test truncation after decode
    const crypto = require('crypto');
  
    const b1 = Buffer.from('YW55=======', 'base64');
    const b2 = Buffer.from('YW55', 'base64');
  
    assert.strictEqual(
      crypto.createHash('sha1').update(b1).digest('hex'),
      crypto.createHash('sha1').update(b2).digest('hex')
    );
  } else {
    common.printSkipMessage('missing crypto');
  }
  
  const ps = Buffer.poolSize;
  Buffer.poolSize = 0;
  assert(Buffer.allocUnsafe(1).parent instanceof ArrayBuffer);
  Buffer.poolSize = ps;
  
  // Test Buffer.copy() segfault
  assert.throws(() => Buffer.allocUnsafe(10).copy(),
                /TypeError: argument should be a Buffer/);
  
  const regErrorMsg =
    /First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object\./;
  
  assert.throws(() => Buffer.from(), regErrorMsg);
  assert.throws(() => Buffer.from(null), regErrorMsg);
  
  // Test prototype getters don't throw
  assert.strictEqual(Buffer.prototype.parent, undefined);
  assert.strictEqual(Buffer.prototype.offset, undefined);
  assert.strictEqual(SlowBuffer.prototype.parent, undefined);
  assert.strictEqual(SlowBuffer.prototype.offset, undefined);
  
  
  {
    // Test that large negative Buffer length inputs don't affect the pool offset.
    // Use the fromArrayLike() variant here because it's more lenient
    // about its input and passes the length directly to allocate().
    assert.deepStrictEqual(Buffer.from({ length: -Buffer.poolSize }),
                           Buffer.from(''));
    assert.deepStrictEqual(Buffer.from({ length: -100 }),
                           Buffer.from(''));
  
    // Check pool offset after that by trying to write string into the pool.
    assert.doesNotThrow(() => Buffer.from('abc'));
  }
  
  
  // Test that ParseArrayIndex handles full uint32
  assert.throws(() => Buffer.from(new ArrayBuffer(0), -1 >>> 0),
                /RangeError: 'offset' is out of bounds/);
  
  // ParseArrayIndex() should reject values that don't fit in a 32 bits size_t.
  assert.throws(() => {
    const a = Buffer.alloc(1);
    const b = Buffer.alloc(1);
    a.copy(b, 0, 0x100000000, 0x100000001);
  }, /out of range index/);
  
  // Unpooled buffer (replaces SlowBuffer)
  {
    const ubuf = Buffer.allocUnsafeSlow(10);
    assert(ubuf);
    assert(ubuf.buffer);
    assert.strictEqual(ubuf.buffer.byteLength, 10);
  }
  
  // Regression test
  assert.doesNotThrow(() => Buffer.from(new ArrayBuffer()));
  
  // Test that ArrayBuffer from a different context is detected correctly
  const arrayBuf = vm.runInNewContext('new ArrayBuffer()');
  assert.doesNotThrow(() => Buffer.from(arrayBuf));
  assert.doesNotThrow(() => Buffer.from({ buffer: arrayBuf }));
  
  assert.throws(() => Buffer.alloc({ valueOf: () => 1 }),
                /"size" argument must be a number/);
  assert.throws(() => Buffer.alloc({ valueOf: () => -1 }),
                /"size" argument must be a number/);
  
  assert.strictEqual(Buffer.prototype.toLocaleString, Buffer.prototype.toString);
  {
    const buf = Buffer.from('test');
    assert.strictEqual(buf.toLocaleString(), buf.toString());
  }
  