commit failing tests

1 files changed, 1682 insertions, 0 deletions

diff --git a/test/bun.js/buffer.test.js b/test/bun.js/buffer.test.js
index 9869f732e..c732b58e3 100644
--- a/test/bun.js/buffer.test.js
+++ b/test/bun.js/buffer.test.js
@@ -6,6 +6,1296 @@ const BufferModule = await import("buffer");
 beforeEach(() => gc());
 afterEach(() => gc());
 
+const assert = {
+  deepStrictEqual(a, b) {
+    expect(b).toStrictEqual(a);
+  },
+  strictEqual(a, b) {
+    expect(a).toBe(b);
+  },
+  throws(a, b) {
+    expect(a).toThrow();
+  },
+};
+
+it("Buffer.alloc", () => {
+  // Verify the maximum Uint8Array size. There is no concrete limit by spec. The
+  // internal limits should be updated if this fails.
+  assert.throws(() => new Uint8Array(2 ** 32 + 1), {
+    message: "Invalid typed array length: 4294967297",
+  });
+
+  const b = Buffer.allocUnsafe(1024);
+  assert.strictEqual(b.length, 1024);
+
+  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(c.length, 512);
+
+  const d = Buffer.from([]);
+  assert.strictEqual(d.length, 0);
+
+  // Test offset properties
+  {
+    const b = Buffer.alloc(128);
+    assert.strictEqual(b.length, 128);
+    assert.strictEqual(b.byteOffset, 0);
+    assert.strictEqual(b.offset, 0);
+  }
+
+  // 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), {
+  // code: "ERR_INVALID_ARG_TYPE",
+  // });
+
+  // Try to create 0-length buffers. Should not throw.
+  Buffer.from("");
+  Buffer.from("", "ascii");
+  Buffer.from("", "latin1");
+  Buffer.alloc(0);
+  Buffer.allocUnsafe(0);
+  new Buffer("");
+  new Buffer("", "ascii");
+  new Buffer("", "latin1");
+  new Buffer("", "binary");
+  Buffer(0);
+
+  const outOfRangeError = {
+    code: "ERR_OUT_OF_RANGE",
+    name: "RangeError",
+  };
+
+  // Try to write a 0-length string beyond the end of b
+  // assert.throws(() => b.write("", 2048), outOfRangeError);
+
+  // // Throw when writing to negative offset
+  // assert.throws(() => b.write("a", -1), outOfRangeError);
+
+  // // Throw when writing past bounds from the pool
+  // assert.throws(() => b.write("a", 2048), outOfRangeError);
+
+  // // Throw when writing to negative offset
+  // assert.throws(() => b.write("a", -1), outOfRangeError);
+
+  // 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");
+    assert.throws(() => writeTest.write("o", "1", "ascii"), {
+      code: "ERR_INVALID_ARG_TYPE",
+    });
+    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 and does not throw.
+  // (see https://github.com/nodejs/node/issues/8127).
+  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(slice.length, 50);
+    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(b[0], 4);
+    assert.strictEqual(b[1], 5);
+    assert.strictEqual(b[2], 6);
+    assert.strictEqual(b[3], 7);
+    const c = b.slice(2, 4);
+    assert.strictEqual(c[0], 6);
+    assert.strictEqual(c[1], 7);
+  }
+
+  {
+    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(Buffer.from("Man").toString("base64"), "TWFu");
+  assert.strictEqual(Buffer.from("Woman").toString("base64"), "V29tYW4=");
+
+  //
+  // Test toString('base64url')
+  //
+  assert.strictEqual(Buffer.from("Man").toString("base64url"), "TWFu");
+  assert.strictEqual(Buffer.from("Woman").toString("base64url"), "V29tYW4");
+
+  {
+    // Test that regular and URL-safe base64 both work both ways
+    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),
+    );
+    assert.deepStrictEqual(
+      Buffer.from("//++/++/++//", "base64url"),
+      Buffer.from(expected),
+    );
+    assert.deepStrictEqual(
+      Buffer.from("__--_--_--__", "base64url"),
+      Buffer.from(expected),
+    );
+  }
+
+  const base64flavors = ["base64", "base64url"];
+
+  {
+    // Test that regular and URL-safe base64 both work both ways with padding
+    const expected = [
+      0xff, 0xff, 0xbe, 0xff, 0xef, 0xbf, 0xfb, 0xef, 0xff, 0xfb,
+    ];
+    assert.deepStrictEqual(
+      Buffer.from("//++/++/++//+w==", "base64"),
+      Buffer.from(expected),
+    );
+    assert.deepStrictEqual(
+      Buffer.from("//++/++/++//+w==", "base64"),
+      Buffer.from(expected),
+    );
+    assert.deepStrictEqual(
+      Buffer.from("//++/++/++//+w==", "base64url"),
+      Buffer.from(expected),
+    );
+    assert.deepStrictEqual(
+      Buffer.from("//++/++/++//+w==", "base64url"),
+      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(Buffer.from(quote).toString("base64"), expected);
+    assert.strictEqual(
+      Buffer.from(quote).toString("base64url"),
+      expected.replaceAll("+", "-").replaceAll("/", "_").replaceAll("=", ""),
+    );
+
+    base64flavors.forEach((encoding) => {
+      let b = Buffer.allocUnsafe(1024);
+      let bytesWritten = b.write(expected, 0, encoding);
+      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, encoding);
+      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, encoding);
+      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, encoding);
+      assert.strictEqual(quote.length, b.length);
+      assert.strictEqual(quote, b.toString("ascii", 0, quote.length));
+    });
+  }
+
+  base64flavors.forEach((encoding) => {
+    assert.strictEqual(Buffer.from("", encoding).toString(), "");
+    assert.strictEqual(Buffer.from("K", encoding).toString(), "");
+
+    // multiple-of-4 with padding
+    assert.strictEqual(Buffer.from("Kg==", encoding).toString(), "*");
+    assert.strictEqual(Buffer.from("Kio=", encoding).toString(), "*".repeat(2));
+    assert.strictEqual(Buffer.from("Kioq", encoding).toString(), "*".repeat(3));
+    assert.strictEqual(
+      Buffer.from("KioqKg==", encoding).toString(),
+      "*".repeat(4),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKio=", encoding).toString(),
+      "*".repeat(5),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioq", encoding).toString(),
+      "*".repeat(6),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKg==", encoding).toString(),
+      "*".repeat(7),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKio=", encoding).toString(),
+      "*".repeat(8),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioq", encoding).toString(),
+      "*".repeat(9),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKg==", encoding).toString(),
+      "*".repeat(10),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKio=", encoding).toString(),
+      "*".repeat(11),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioq", encoding).toString(),
+      "*".repeat(12),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKg==", encoding).toString(),
+      "*".repeat(13),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKio=", encoding).toString(),
+      "*".repeat(14),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioq", encoding).toString(),
+      "*".repeat(15),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKg==", encoding).toString(),
+      "*".repeat(16),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKio=", encoding).toString(),
+      "*".repeat(17),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKioq", encoding).toString(),
+      "*".repeat(18),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKioqKg==", encoding).toString(),
+      "*".repeat(19),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKioqKio=", encoding).toString(),
+      "*".repeat(20),
+    );
+
+    // No padding, not a multiple of 4
+    assert.strictEqual(Buffer.from("Kg", encoding).toString(), "*");
+    assert.strictEqual(Buffer.from("Kio", encoding).toString(), "*".repeat(2));
+    assert.strictEqual(
+      Buffer.from("KioqKg", encoding).toString(),
+      "*".repeat(4),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKio", encoding).toString(),
+      "*".repeat(5),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKg", encoding).toString(),
+      "*".repeat(7),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKio", encoding).toString(),
+      "*".repeat(8),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKg", encoding).toString(),
+      "*".repeat(10),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKio", encoding).toString(),
+      "*".repeat(11),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKg", encoding).toString(),
+      "*".repeat(13),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKio", encoding).toString(),
+      "*".repeat(14),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKg", encoding).toString(),
+      "*".repeat(16),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKio", encoding).toString(),
+      "*".repeat(17),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKioqKg", encoding).toString(),
+      "*".repeat(19),
+    );
+    assert.strictEqual(
+      Buffer.from("KioqKioqKioqKioqKioqKioqKio", encoding).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==", "base64url")
+      .length,
+    32,
+  );
+  assert.strictEqual(
+    Buffer.from("72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw=", "base64")
+      .length,
+    32,
+  );
+  assert.strictEqual(
+    Buffer.from("72INjkR5fchcxk9-VgdGPFJDxUBFR5_rMFsghgxADiw=", "base64url")
+      .length,
+    32,
+  );
+  assert.strictEqual(
+    Buffer.from("72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw", "base64").length,
+    32,
+  );
+  assert.strictEqual(
+    Buffer.from("72INjkR5fchcxk9-VgdGPFJDxUBFR5_rMFsghgxADiw", "base64url")
+      .length,
+    32,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg==", "base64")
+      .length,
+    31,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg==", "base64url")
+      .length,
+    31,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg=", "base64").length,
+    31,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg=", "base64url")
+      .length,
+    31,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg", "base64").length,
+    31,
+  );
+  assert.strictEqual(
+    Buffer.from("w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg", "base64url")
+      .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==");
+  }
+
+  {
+    // This string encodes single '.' character in UTF-16
+    const dot = Buffer.from("//4uAA", "base64url");
+    assert.strictEqual(dot[0], 0xff);
+    assert.strictEqual(dot[1], 0xfe);
+    assert.strictEqual(dot[2], 0x2e);
+    assert.strictEqual(dot[3], 0x00);
+    assert.strictEqual(dot.toString("base64url"), "__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!",
+    );
+  }
+
+  {
+    // Writing base64url 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, "base64url");
+    }
+    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(b[i], "h".charCodeAt(0));
+    }
+
+    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(x.inspect(), "<Buffer 81 a3 66 6f 6f a3 62 61 72>");
+
+  {
+    const z = x.slice(4);
+    assert.strictEqual(z.length, 5);
+    assert.strictEqual(z[0], 0x6f);
+    assert.strictEqual(z[1], 0xa3);
+    assert.strictEqual(z[2], 0x62);
+    assert.strictEqual(z[3], 0x61);
+    assert.strictEqual(z[4], 0x72);
+  }
+
+  {
+    const z = x.slice(0);
+    assert.strictEqual(z.length, x.length);
+  }
+
+  {
+    const z = x.slice(0, 4);
+    assert.strictEqual(z.length, 4);
+    assert.strictEqual(z[0], 0x81);
+    assert.strictEqual(z[1], 0xa3);
+  }
+
+  {
+    const z = x.slice(0, 9);
+    assert.strictEqual(z.length, 9);
+  }
+
+  {
+    const z = x.slice(1, 4);
+    assert.strictEqual(z.length, 3);
+    assert.strictEqual(z[0], 0xa3);
+  }
+
+  {
+    const z = x.slice(2, 4);
+    assert.strictEqual(z.length, 2);
+    assert.strictEqual(z[0], 0x66);
+    assert.strictEqual(z[1], 0x6f);
+  }
+
+  ["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(b[0], 0xff);
+    assert.strictEqual(b[1], 0xad);
+    assert.strictEqual(b[2], 0xbe);
+    assert.strictEqual(b[3], 0xef);
+    s = String.fromCharCode(0xaaee);
+    b.write(s, 0, "latin1");
+    assert.strictEqual(b[0], 0xee);
+    assert.strictEqual(b[1], 0xad);
+    assert.strictEqual(b[2], 0xbe);
+    assert.strictEqual(b[3], 0xef);
+  }
+
+  {
+    // 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(b[0], 0xff);
+    assert.strictEqual(b[1], 0xad);
+    assert.strictEqual(b[2], 0xbe);
+    assert.strictEqual(b[3], 0xef);
+    s = String.fromCharCode(0xaaee);
+    b.write(s, 0, "latin1");
+    assert.strictEqual(b[0], 0xee);
+    assert.strictEqual(b[1], 0xad);
+    assert.strictEqual(b[2], 0xbe);
+    assert.strictEqual(b[3], 0xef);
+  }
+
+  {
+    // https://github.com/nodejs/node-v0.x-archive/pull/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
+  }
+
+  {
+    // https://github.com/nodejs/node-v0.x-archive/issues/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(b.writeUInt32LE(0, 0), 4);
+    assert.strictEqual(b.writeUInt16LE(0, 4), 6);
+    assert.strictEqual(b.writeUInt8(0, 6), 7);
+    assert.strictEqual(b.writeInt8(0, 7), 8);
+    assert.strictEqual(b.writeDoubleLE(0, 8), 16);
+  }
+
+  {
+    // 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(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), outOfRangeError);
+  assert.throws(() => Buffer.alloc(16).writeDoubleLE(0, 9), outOfRangeError);
+
+  // Attempt to overflow buffers, similar to previous bug in array buffers
+  assert.throws(
+    () => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
+    outOfRangeError,
+  );
+  assert.throws(
+    () => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
+    outOfRangeError,
+  );
+
+  // Ensure negative values can't get past offset
+  assert.throws(
+    () => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1),
+    outOfRangeError,
+  );
+  assert.throws(
+    () => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1),
+    outOfRangeError,
+  );
+
+  // 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 https://github.com/nodejs/node-v0.x-archive/issues/5482:
+  // should throw but not assert in C++ land.
+  assert.throws(() => Buffer.from("", "buffer"), {
+    code: "ERR_UNKNOWN_ENCODING",
+    name: "TypeError",
+    message: "Unknown encoding: buffer",
+  });
+
+  // Regression test for https://github.com/nodejs/node-v0.x-archive/issues/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) {
+  // eslint-disable-line node-core/crypto-check
+  // 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;
+
+  assert.throws(() => Buffer.allocUnsafe(10).copy(), {
+    code: "ERR_INVALID_ARG_TYPE",
+    name: "TypeError",
+    message:
+      'The "target" argument must be an instance of Buffer or ' +
+      "Uint8Array. Received undefined",
+  });
+
+  assert.throws(() => Buffer.from(), {
+    name: "TypeError",
+    message:
+      "The first argument must be of type string or an instance of " +
+      "Buffer, ArrayBuffer, or Array or an Array-like Object. Received undefined",
+  });
+  assert.throws(() => Buffer.from(null), {
+    name: "TypeError",
+    message:
+      "The first argument must be of type string or an instance of " +
+      "Buffer, ArrayBuffer, or Array or an Array-like Object. Received null",
+  });
+
+  // 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.
+    Buffer.from("abc");
+  }
+
+  // Test that ParseArrayIndex handles full uint32
+  {
+    const errMsg = common.expectsError({
+      code: "ERR_BUFFER_OUT_OF_BOUNDS",
+      name: "RangeError",
+      message: '"offset" is outside of buffer bounds',
+    });
+    assert.throws(() => Buffer.from(new ArrayBuffer(0), -1 >>> 0), errMsg);
+  }
+
+  // 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);
+  }, outOfRangeError);
+
+  // Unpooled buffer (replaces SlowBuffer)
+  {
+    const ubuf = Buffer.allocUnsafeSlow(10);
+    assert(ubuf);
+    assert(ubuf.buffer);
+    assert.strictEqual(ubuf.buffer.byteLength, 10);
+  }
+
+  // Regression test to verify that an empty ArrayBuffer does not throw.
+  Buffer.from(new ArrayBuffer());
+
+  // Test that ArrayBuffer from a different context is detected correctly.
+  const arrayBuf = vm.runInNewContext("new ArrayBuffer()");
+  Buffer.from(arrayBuf);
+  Buffer.from({ buffer: arrayBuf });
+
+  assert.throws(
+    () => Buffer.alloc({ valueOf: () => 1 }),
+    /"size" argument must be of type number/,
+  );
+  assert.throws(
+    () => Buffer.alloc({ valueOf: () => -1 }),
+    /"size" argument must be of type number/,
+  );
+
+  assert.strictEqual(
+    Buffer.prototype.toLocaleString,
+    Buffer.prototype.toString,
+  );
+  {
+    const buf = Buffer.from("test");
+    assert.strictEqual(buf.toLocaleString(), buf.toString());
+  }
+
+  assert.throws(
+    () => {
+      Buffer.alloc(0x1000, "This is not correctly encoded", "hex");
+    },
+    {
+      code: "ERR_INVALID_ARG_VALUE",
+      name: "TypeError",
+    },
+  );
+
+  assert.throws(
+    () => {
+      Buffer.alloc(0x1000, "c", "hex");
+    },
+    {
+      code: "ERR_INVALID_ARG_VALUE",
+      name: "TypeError",
+    },
+  );
+
+  assert.throws(
+    () => {
+      Buffer.alloc(1, Buffer.alloc(0));
+    },
+    {
+      code: "ERR_INVALID_ARG_VALUE",
+      name: "TypeError",
+    },
+  );
+
+  assert.throws(
+    () => {
+      Buffer.alloc(40, "x", 20);
+    },
+    {
+      code: "ERR_INVALID_ARG_TYPE",
+      name: "TypeError",
+    },
+  );
+});
+
 it("Buffer.toJSON()", () => {
   expect(JSON.stringify(Buffer.from("hello"))).toBe(
     JSON.stringify({
@@ -1003,3 +2293,395 @@ it("new Buffer() (Node.js test/test-buffer-new.js)", () => {
   // Test an array like entry with the length set to NaN.
   expect(Buffer.from({ length: NaN })).toStrictEqual(Buffer.alloc(0));
 });
+
+it("Buffer.fill (Node.js tests)", () => {
+  "use strict";
+  const SIZE = 28;
+
+  const buf1 = Buffer.allocUnsafe(SIZE);
+  const buf2 = Buffer.allocUnsafe(SIZE);
+
+  function assertEqual(a, b) {
+    expect(a).toEqual(b);
+  }
+
+  // Default encoding
+  testBufs("abc");
+  testBufs("\u0222aa");
+  testBufs("a\u0234b\u0235c\u0236");
+  testBufs("abc", 4);
+  testBufs("abc", 5);
+  testBufs("abc", SIZE);
+  testBufs("\u0222aa", 2);
+  testBufs("\u0222aa", 8);
+  testBufs("a\u0234b\u0235c\u0236", 4);
+  testBufs("a\u0234b\u0235c\u0236", 12);
+  testBufs("abc", 4, 1);
+  testBufs("abc", 5, 1);
+  testBufs("\u0222aa", 8, 1);
+  testBufs("a\u0234b\u0235c\u0236", 4, 1);
+  testBufs("a\u0234b\u0235c\u0236", 12, 1);
+
+  // UTF8
+  testBufs("abc", "utf8");
+  testBufs("\u0222aa", "utf8");
+  testBufs("a\u0234b\u0235c\u0236", "utf8");
+  testBufs("abc", 4, "utf8");
+  testBufs("abc", 5, "utf8");
+  testBufs("abc", SIZE, "utf8");
+  testBufs("\u0222aa", 2, "utf8");
+  testBufs("\u0222aa", 8, "utf8");
+  testBufs("a\u0234b\u0235c\u0236", 4, "utf8");
+  testBufs("a\u0234b\u0235c\u0236", 12, "utf8");
+  testBufs("abc", 4, 1, "utf8");
+  testBufs("abc", 5, 1, "utf8");
+  testBufs("\u0222aa", 8, 1, "utf8");
+  testBufs("a\u0234b\u0235c\u0236", 4, 1, "utf8");
+  testBufs("a\u0234b\u0235c\u0236", 12, 1, "utf8");
+  assertEqual(Buffer.allocUnsafe(1).fill(0).fill("\u0222")[0], 0xc8);
+
+  // BINARY
+  testBufs("abc", "binary");
+  testBufs("\u0222aa", "binary");
+  testBufs("a\u0234b\u0235c\u0236", "binary");
+  testBufs("abc", 4, "binary");
+  testBufs("abc", 5, "binary");
+  testBufs("abc", SIZE, "binary");
+  testBufs("\u0222aa", 2, "binary");
+  testBufs("\u0222aa", 8, "binary");
+  testBufs("a\u0234b\u0235c\u0236", 4, "binary");
+  testBufs("a\u0234b\u0235c\u0236", 12, "binary");
+  testBufs("abc", 4, 1, "binary");
+  testBufs("abc", 5, 1, "binary");
+  testBufs("\u0222aa", 8, 1, "binary");
+  testBufs("a\u0234b\u0235c\u0236", 4, 1, "binary");
+  testBufs("a\u0234b\u0235c\u0236", 12, 1, "binary");
+
+  // LATIN1
+  testBufs("abc", "latin1");
+  testBufs("\u0222aa", "latin1");
+  testBufs("a\u0234b\u0235c\u0236", "latin1");
+  testBufs("abc", 4, "latin1");
+  testBufs("abc", 5, "latin1");
+  testBufs("abc", SIZE, "latin1");
+  testBufs("\u0222aa", 2, "latin1");
+  testBufs("\u0222aa", 8, "latin1");
+  testBufs("a\u0234b\u0235c\u0236", 4, "latin1");
+  testBufs("a\u0234b\u0235c\u0236", 12, "latin1");
+  testBufs("abc", 4, 1, "latin1");
+  testBufs("abc", 5, 1, "latin1");
+  testBufs("\u0222aa", 8, 1, "latin1");
+  testBufs("a\u0234b\u0235c\u0236", 4, 1, "latin1");
+  testBufs("a\u0234b\u0235c\u0236", 12, 1, "latin1");
+
+  // UCS2
+  testBufs("abc", "ucs2");
+  testBufs("\u0222aa", "ucs2");
+  testBufs("a\u0234b\u0235c\u0236", "ucs2");
+  testBufs("abc", 4, "ucs2");
+  testBufs("abc", SIZE, "ucs2");
+  testBufs("\u0222aa", 2, "ucs2");
+  testBufs("\u0222aa", 8, "ucs2");
+  testBufs("a\u0234b\u0235c\u0236", 4, "ucs2");
+  testBufs("a\u0234b\u0235c\u0236", 12, "ucs2");
+  testBufs("abc", 4, 1, "ucs2");
+  testBufs("abc", 5, 1, "ucs2");
+  testBufs("\u0222aa", 8, 1, "ucs2");
+  testBufs("a\u0234b\u0235c\u0236", 4, 1, "ucs2");
+  testBufs("a\u0234b\u0235c\u0236", 12, 1, "ucs2");
+  assertEqual(Buffer.allocUnsafe(1).fill("\u0222", "ucs2")[0], 0x22);
+
+  // HEX
+  testBufs("616263", "hex");
+  testBufs("c8a26161", "hex");
+  testBufs("61c8b462c8b563c8b6", "hex");
+  testBufs("616263", 4, "hex");
+  testBufs("616263", 5, "hex");
+  testBufs("616263", SIZE, "hex");
+  testBufs("c8a26161", 2, "hex");
+  testBufs("c8a26161", 8, "hex");
+  testBufs("61c8b462c8b563c8b6", 4, "hex");
+  testBufs("61c8b462c8b563c8b6", 12, "hex");
+  testBufs("616263", 4, 1, "hex");
+  testBufs("616263", 5, 1, "hex");
+  testBufs("c8a26161", 8, 1, "hex");
+  testBufs("61c8b462c8b563c8b6", 4, 1, "hex");
+  testBufs("61c8b462c8b563c8b6", 12, 1, "hex");
+
+  expect(() => {
+    const buf = Buffer.allocUnsafe(SIZE);
+
+    buf.fill("yKJh", "hex");
+  }).toThrow();
+
+  expect(() => {
+    const buf = Buffer.allocUnsafe(SIZE);
+
+    buf.fill("\u0222", "hex");
+  }).toThrow();
+
+  // BASE64
+  testBufs("YWJj", "base64");
+  testBufs("yKJhYQ==", "base64");
+  testBufs("Yci0Ysi1Y8i2", "base64");
+  testBufs("YWJj", 4, "base64");
+  testBufs("YWJj", SIZE, "base64");
+  testBufs("yKJhYQ==", 2, "base64");
+  testBufs("yKJhYQ==", 8, "base64");
+  testBufs("Yci0Ysi1Y8i2", 4, "base64");
+  testBufs("Yci0Ysi1Y8i2", 12, "base64");
+  testBufs("YWJj", 4, 1, "base64");
+  testBufs("YWJj", 5, 1, "base64");
+  testBufs("yKJhYQ==", 8, 1, "base64");
+  testBufs("Yci0Ysi1Y8i2", 4, 1, "base64");
+  testBufs("Yci0Ysi1Y8i2", 12, 1, "base64");
+
+  // BASE64URL
+  testBufs("YWJj", "base64url");
+  testBufs("yKJhYQ", "base64url");
+  testBufs("Yci0Ysi1Y8i2", "base64url");
+  testBufs("YWJj", 4, "base64url");
+  testBufs("YWJj", SIZE, "base64url");
+  testBufs("yKJhYQ", 2, "base64url");
+  testBufs("yKJhYQ", 8, "base64url");
+  testBufs("Yci0Ysi1Y8i2", 4, "base64url");
+  testBufs("Yci0Ysi1Y8i2", 12, "base64url");
+  testBufs("YWJj", 4, 1, "base64url");
+  testBufs("YWJj", 5, 1, "base64url");
+  testBufs("yKJhYQ", 8, 1, "base64url");
+  testBufs("Yci0Ysi1Y8i2", 4, 1, "base64url");
+  testBufs("Yci0Ysi1Y8i2", 12, 1, "base64url");
+
+  // Buffer
+  function deepStrictEqualValues(buf, arr) {
+    for (const [index, value] of buf.entries()) {
+      expect(value).toStrictEqual(arr[index]);
+    }
+  }
+
+  const buf2Fill = Buffer.allocUnsafe(1).fill(2);
+  deepStrictEqualValues(genBuffer(4, [buf2Fill]), [2, 2, 2, 2]);
+  deepStrictEqualValues(genBuffer(4, [buf2Fill, 1]), [0, 2, 2, 2]);
+  deepStrictEqualValues(genBuffer(4, [buf2Fill, 1, 3]), [0, 2, 2, 0]);
+  deepStrictEqualValues(genBuffer(4, [buf2Fill, 1, 1]), [0, 0, 0, 0]);
+  const hexBufFill = Buffer.allocUnsafe(2).fill(0).fill("0102", "hex");
+  deepStrictEqualValues(genBuffer(4, [hexBufFill]), [1, 2, 1, 2]);
+  deepStrictEqualValues(genBuffer(4, [hexBufFill, 1]), [0, 1, 2, 1]);
+  deepStrictEqualValues(genBuffer(4, [hexBufFill, 1, 3]), [0, 1, 2, 0]);
+  deepStrictEqualValues(genBuffer(4, [hexBufFill, 1, 1]), [0, 0, 0, 0]);
+
+  // Check exceptions
+  [
+    [0, -1],
+    [0, 0, buf1.length + 1],
+    ["", -1],
+    ["", 0, buf1.length + 1],
+    ["", 1, -1],
+  ].forEach((args) => {
+    expect(() => buf1.fill(...args)).toThrow();
+  });
+
+  expect(() => buf1.fill("a", 0, buf1.length, "node rocks!")).toThrow();
+
+  [
+    ["a", 0, 0, NaN],
+    ["a", 0, 0, false],
+  ].forEach((args) => {
+    expect(() => buf1.fill(...args)).toThrow();
+  });
+
+  expect(() => buf1.fill("a", 0, 0, "foo")).toThrow();
+
+  function genBuffer(size, args) {
+    const b = Buffer.allocUnsafe(size);
+    return b.fill(0).fill.apply(b, args);
+  }
+
+  function bufReset() {
+    buf1.fill(0);
+    buf2.fill(0);
+  }
+
+  // This is mostly accurate. Except write() won't write partial bytes to the
+  // string while fill() blindly copies bytes into memory. To account for that an
+  // error will be thrown if not all the data can be written, and the SIZE has
+  // been massaged to work with the input characters.
+  function writeToFill(string, offset, end, encoding) {
+    if (typeof offset === "string") {
+      encoding = offset;
+      offset = 0;
+      end = buf2.length;
+    } else if (typeof end === "string") {
+      encoding = end;
+      end = buf2.length;
+    } else if (end === undefined) {
+      end = buf2.length;
+    }
+
+    // Should never be reached.
+    if (offset < 0 || end > buf2.length) throw new ERR_OUT_OF_RANGE();
+
+    if (end <= offset) return buf2;
+
+    offset >>>= 0;
+    end >>>= 0;
+    expect(offset <= buf2.length).toBe(true);
+
+    // Convert "end" to "length" (which write understands).
+    const length = end - offset < 0 ? 0 : end - offset;
+
+    let wasZero = false;
+    do {
+      const written = buf2.write(string, offset, length, encoding);
+      offset += written;
+      // Safety check in case write falls into infinite loop.
+      if (written === 0) {
+        if (wasZero)
+          throw new Error("Could not write all data to Buffer at " + offset);
+        else wasZero = true;
+      }
+    } while (offset < buf2.length);
+
+    return buf2;
+  }
+
+  function testBufs(string, offset, length, encoding) {
+    bufReset();
+    buf1.fill.apply(buf1, arguments);
+    // Swap bytes on BE archs for ucs2 encoding.
+    expect(buf1.fill.apply(buf1, arguments)).toStrictEqual(
+      writeToFill.apply(null, arguments),
+    );
+  }
+
+  // Make sure these throw.
+  expect(() => Buffer.allocUnsafe(8).fill("a", -1)).toThrow();
+  expect(() => Buffer.allocUnsafe(8).fill("a", 0, 9)).toThrow();
+
+  // Make sure this doesn't hang indefinitely.
+  Buffer.allocUnsafe(8).fill("");
+  Buffer.alloc(8, "");
+
+  {
+    const buf = Buffer.alloc(64, 10);
+    for (let i = 0; i < buf.length; i++) assertEqual(buf[i], 10);
+
+    buf.fill(11, 0, buf.length >> 1);
+    for (let i = 0; i < buf.length >> 1; i++) assertEqual(buf[i], 11);
+    for (let i = (buf.length >> 1) + 1; i < buf.length; i++)
+      assertEqual(buf[i], 10);
+
+    buf.fill("h");
+    for (let i = 0; i < buf.length; i++) assertEqual(buf[i], "h".charCodeAt(0));
+
+    buf.fill(0);
+    for (let i = 0; i < buf.length; i++) assertEqual(buf[i], 0);
+
+    buf.fill(null);
+    for (let i = 0; i < buf.length; i++) assertEqual(buf[i], 0);
+
+    buf.fill(1, 16, 32);
+    for (let i = 0; i < 16; i++) assertEqual(buf[i], 0);
+    for (let i = 16; i < 32; i++) assertEqual(buf[i], 1);
+    for (let i = 32; i < buf.length; i++) assertEqual(buf[i], 0);
+  }
+
+  {
+    const buf = Buffer.alloc(10, "abc");
+    assertEqual(buf.toString(), "abcabcabca");
+    buf.fill("է");
+    assertEqual(buf.toString(), "էէէէէ");
+  }
+
+  // // Testing process.binding. Make sure "start" is properly checked for range
+  // // errors.
+  // assert.throws(
+  //   () => {
+  //     internalBinding("buffer").fill(Buffer.alloc(1), 1, -1, 0, 1);
+  //   },
+  //   { code: "ERR_OUT_OF_RANGE" },
+  // );
+
+  // Make sure "end" is properly checked, even if it's magically mangled using
+  // Symbol.toPrimitive.
+  {
+    expect(() => {
+      const end = {
+        [Symbol.toPrimitive]() {
+          return 1;
+        },
+      };
+      Buffer.alloc(1).fill(Buffer.alloc(1), 0, end);
+    }).toThrow();
+  }
+
+  // Testing process.binding. Make sure "end" is properly checked for range
+  // errors.
+  // assert.throws(
+  //   () => {
+  //     internalBinding("buffer").fill(Buffer.alloc(1), 1, 1, -2, 1);
+  //   },
+  //   { code: "ERR_OUT_OF_RANGE" },
+  // );
+
+  // Test that bypassing 'length' won't cause an abort.
+  expect(() => {
+    const buf = Buffer.from("w00t");
+    Object.defineProperty(buf, "length", {
+      value: 1337,
+      enumerable: true,
+    });
+    buf.fill("");
+  }).toThrow();
+
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("ab", "utf16le"),
+    Buffer.from("61006200610062006100620061006200", "hex"),
+  );
+
+  assertEqual(
+    Buffer.allocUnsafeSlow(15).fill("ab", "utf16le"),
+    Buffer.from("610062006100620061006200610062", "hex"),
+  );
+
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("ab", "utf16le"),
+    Buffer.from("61006200610062006100620061006200", "hex"),
+  );
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("a", "utf16le"),
+    Buffer.from("61006100610061006100610061006100", "hex"),
+  );
+
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("a", "utf16le").toString("utf16le"),
+    "a".repeat(8),
+  );
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("a", "latin1").toString("latin1"),
+    "a".repeat(16),
+  );
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("a", "utf8").toString("utf8"),
+    "a".repeat(16),
+  );
+
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("Љ", "utf16le").toString("utf16le"),
+    "Љ".repeat(8),
+  );
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("Љ", "latin1").toString("latin1"),
+    "\t".repeat(16),
+  );
+  assertEqual(
+    Buffer.allocUnsafeSlow(16).fill("Љ", "utf8").toString("utf8"),
+    "Љ".repeat(8),
+  );
+
+  expect(() => {
+    const buf = Buffer.from("a".repeat(1000));
+
+    buf.fill("This is not correctly encoded", "hex");
+  }).toThrow();
+});