diff --git a/test/parallel/test-buffer-swap.js b/test/parallel/test-buffer-swap.js
index bcb636edb1733f..82b550790e7232 100644
--- a/test/parallel/test-buffer-swap.js
+++ b/test/parallel/test-buffer-swap.js
@@ -4,135 +4,149 @@ require('../common');
 const assert = require('assert');
 
 // Test buffers small enough to use the JS implementation
-const buf = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
-                         0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10]);
-
-assert.strictEqual(buf, buf.swap16());
-assert.deepStrictEqual(buf, Buffer.from([0x02, 0x01, 0x04, 0x03, 0x06, 0x05,
-                                         0x08, 0x07, 0x0a, 0x09, 0x0c, 0x0b,
-                                         0x0e, 0x0d, 0x10, 0x0f]));
-buf.swap16(); // restore
-
-assert.strictEqual(buf, buf.swap32());
-assert.deepStrictEqual(buf, Buffer.from([0x04, 0x03, 0x02, 0x01, 0x08, 0x07,
-                                         0x06, 0x05, 0x0c, 0x0b, 0x0a, 0x09,
-                                         0x10, 0x0f, 0x0e, 0x0d]));
-buf.swap32(); // restore
-
-assert.strictEqual(buf, buf.swap64());
-assert.deepStrictEqual(buf, Buffer.from([0x08, 0x07, 0x06, 0x05, 0x04, 0x03,
-                                         0x02, 0x01, 0x10, 0x0f, 0x0e, 0x0d,
-                                         0x0c, 0x0b, 0x0a, 0x09]));
+{
+  const buf = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+                           0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10]);
+
+  assert.strictEqual(buf, buf.swap16());
+  assert.deepStrictEqual(buf, Buffer.from([0x02, 0x01, 0x04, 0x03, 0x06, 0x05,
+                                           0x08, 0x07, 0x0a, 0x09, 0x0c, 0x0b,
+                                           0x0e, 0x0d, 0x10, 0x0f]));
+  buf.swap16(); // restore
+
+  assert.strictEqual(buf, buf.swap32());
+  assert.deepStrictEqual(buf, Buffer.from([0x04, 0x03, 0x02, 0x01, 0x08, 0x07,
+                                           0x06, 0x05, 0x0c, 0x0b, 0x0a, 0x09,
+                                           0x10, 0x0f, 0x0e, 0x0d]));
+  buf.swap32(); // restore
+
+  assert.strictEqual(buf, buf.swap64());
+  assert.deepStrictEqual(buf, Buffer.from([0x08, 0x07, 0x06, 0x05, 0x04, 0x03,
+                                           0x02, 0x01, 0x10, 0x0f, 0x0e, 0x0d,
+                                           0x0c, 0x0b, 0x0a, 0x09]));
+}
 
 // Operates in-place
-const buf3 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7]);
-buf3.slice(1, 5).swap32();
-assert.deepStrictEqual(buf3, Buffer.from([0x1, 0x5, 0x4, 0x3, 0x2, 0x6, 0x7]));
-
-buf3.slice(1, 5).swap16();
-assert.deepStrictEqual(buf3, Buffer.from([0x1, 0x4, 0x5, 0x2, 0x3, 0x6, 0x7]));
-
-const buf3_64 = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-                             0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
-                             0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-                             0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10]);
-buf3_64.slice(2, 18).swap64();
-assert.deepStrictEqual(buf3_64, Buffer.from([0x01, 0x02, 0x0a, 0x09, 0x08, 0x07,
-                                             0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
-                                             0x10, 0x0f, 0x0e, 0x0d, 0x0c, 0x0b,
-                                             0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-                                             0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
-                                             0x0f, 0x10]));
-
-// Force use of native code (Buffer size above threshold limit for js impl)
-const buf4A = new Uint32Array(256).fill(0x04030201);
-const buf4 = Buffer.from(buf4A.buffer, buf4A.byteOffset);
-const buf5A = new Uint32Array(256).fill(0x03040102);
-const buf5 = Buffer.from(buf5A.buffer, buf5A.byteOffset);
-
-buf4.swap16();
-assert.deepStrictEqual(buf4, buf5);
-
-const buf6A = new Uint32Array(256).fill(0x04030201);
-const buf6 = Buffer.from(buf6A.buffer);
-const bu7A = new Uint32Array(256).fill(0x01020304);
-const buf7 = Buffer.from(bu7A.buffer, bu7A.byteOffset);
-
-buf6.swap32();
-assert.deepStrictEqual(buf6, buf7);
-
-const buf8A = new Uint8Array(256 * 8);
-const buf9A = new Uint8Array(256 * 8);
-for (let i = 0; i < buf8A.length; i++) {
-  buf8A[i] = i % 8;
-  buf9A[buf9A.length - i - 1] = i % 8;
+{
+  const buf = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7]);
+  buf.slice(1, 5).swap32();
+  assert.deepStrictEqual(buf, Buffer.from([0x1, 0x5, 0x4, 0x3, 0x2, 0x6, 0x7]));
+  buf.slice(1, 5).swap16();
+  assert.deepStrictEqual(buf, Buffer.from([0x1, 0x4, 0x5, 0x2, 0x3, 0x6, 0x7]));
+
+  // Length assertions
+  const re16 = /Buffer size must be a multiple of 16-bits/;
+  const re32 = /Buffer size must be a multiple of 32-bits/;
+  const re64 = /Buffer size must be a multiple of 64-bits/;
+
+  assert.throws(() => Buffer.from(buf).swap16(), re16);
+  assert.throws(() => Buffer.alloc(1025).swap16(), re16);
+  assert.throws(() => Buffer.from(buf).swap32(), re32);
+  assert.throws(() => buf.slice(1, 3).swap32(), re32);
+  assert.throws(() => Buffer.alloc(1025).swap32(), re32);
+  assert.throws(() => buf.slice(1, 3).swap64(), re64);
+  assert.throws(() => Buffer.alloc(1025).swap64(), re64);
 }
-const buf8 = Buffer.from(buf8A.buffer, buf8A.byteOffset);
-const buf9 = Buffer.from(buf9A.buffer, buf9A.byteOffset);
-
-buf8.swap64();
-assert.deepStrictEqual(buf8, buf9);
 
-// Test native code with buffers that are not memory-aligned
-const buf10A = new Uint8Array(256 * 8);
-const buf11A = new Uint8Array(256 * 8 - 2);
-for (let i = 0; i < buf10A.length; i++) {
-  buf10A[i] = i % 2;
-}
-for (let i = 1; i < buf11A.length; i++) {
-  buf11A[buf11A.length - i] = (i + 1) % 2;
-}
-const buf10 = Buffer.from(buf10A.buffer, buf10A.byteOffset);
-// 0|1 0|1 0|1...
-const buf11 = Buffer.from(buf11A.buffer, buf11A.byteOffset);
-// 0|0 1|0 1|0...
+{
+  const buf = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                           0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
+                           0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                           0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10]);
 
-buf10.slice(1, buf10.length - 1).swap16();
-assert.deepStrictEqual(buf10.slice(0, buf11.length), buf11);
+  buf.slice(2, 18).swap64();
 
+  assert.deepStrictEqual(buf, Buffer.from([0x01, 0x02, 0x0a, 0x09, 0x08, 0x07,
+                                           0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
+                                           0x10, 0x0f, 0x0e, 0x0d, 0x0c, 0x0b,
+                                           0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                                           0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+                                           0x0f, 0x10]));
+}
 
-const buf12A = new Uint8Array(256 * 8);
-const buf13A = new Uint8Array(256 * 8 - 4);
-for (let i = 0; i < buf12A.length; i++) {
-  buf12A[i] = i % 4;
+// Force use of native code (Buffer size above threshold limit for js impl)
+{
+  const bufData = new Uint32Array(256).fill(0x04030201);
+  const buf = Buffer.from(bufData.buffer, bufData.byteOffset);
+  const otherBufData = new Uint32Array(256).fill(0x03040102);
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  buf.swap16();
+  assert.deepStrictEqual(buf, otherBuf);
 }
-for (let i = 1; i < buf13A.length; i++) {
-  buf13A[buf13A.length - i] = (i + 1) % 4;
+
+{
+  const bufData = new Uint32Array(256).fill(0x04030201);
+  const buf = Buffer.from(bufData.buffer);
+  const otherBufData = new Uint32Array(256).fill(0x01020304);
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  buf.swap32();
+  assert.deepStrictEqual(buf, otherBuf);
 }
-const buf12 = Buffer.from(buf12A.buffer, buf12A.byteOffset);
-// 0|1 2 3 0|1 2 3...
-const buf13 = Buffer.from(buf13A.buffer, buf13A.byteOffset);
-// 0|0 3 2 1|0 3 2...
 
-buf12.slice(1, buf12.length - 3).swap32();
-assert.deepStrictEqual(buf12.slice(0, buf13.length), buf13);
+{
+  const bufData = new Uint8Array(256 * 8);
+  const otherBufData = new Uint8Array(256 * 8);
+  for (let i = 0; i < bufData.length; i++) {
+    bufData[i] = i % 8;
+    otherBufData[otherBufData.length - i - 1] = i % 8;
+  }
+  const buf = Buffer.from(bufData.buffer, bufData.byteOffset);
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  buf.swap64();
+  assert.deepStrictEqual(buf, otherBuf);
+}
 
+// Test native code with buffers that are not memory-aligned
+{
+  const bufData = new Uint8Array(256 * 8);
+  const otherBufData = new Uint8Array(256 * 8 - 2);
+  for (let i = 0; i < bufData.length; i++) {
+    bufData[i] = i % 2;
+  }
+  for (let i = 1; i < otherBufData.length; i++) {
+    otherBufData[otherBufData.length - i] = (i + 1) % 2;
+  }
+  const buf = Buffer.from(bufData.buffer, bufData.byteOffset);
+  // 0|1 0|1 0|1...
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  // 0|0 1|0 1|0...
+
+  buf.slice(1, buf.length - 1).swap16();
+  assert.deepStrictEqual(buf.slice(0, otherBuf.length), otherBuf);
+}
 
-const buf14A = new Uint8Array(256 * 8);
-const buf15A = new Uint8Array(256 * 8 - 8);
-for (let i = 0; i < buf14A.length; i++) {
-  buf14A[i] = i % 8;
+{
+  const bufData = new Uint8Array(256 * 8);
+  const otherBufData = new Uint8Array(256 * 8 - 4);
+  for (let i = 0; i < bufData.length; i++) {
+    bufData[i] = i % 4;
+  }
+  for (let i = 1; i < otherBufData.length; i++) {
+    otherBufData[otherBufData.length - i] = (i + 1) % 4;
+  }
+  const buf = Buffer.from(bufData.buffer, bufData.byteOffset);
+  // 0|1 2 3 0|1 2 3...
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  // 0|0 3 2 1|0 3 2...
+
+  buf.slice(1, buf.length - 3).swap32();
+  assert.deepStrictEqual(buf.slice(0, otherBuf.length), otherBuf);
 }
-for (let i = 1; i < buf15A.length; i++) {
-  buf15A[buf15A.length - i] = (i + 1) % 8;
+
+{
+  const bufData = new Uint8Array(256 * 8);
+  const otherBufData = new Uint8Array(256 * 8 - 8);
+  for (let i = 0; i < bufData.length; i++) {
+    bufData[i] = i % 8;
+  }
+  for (let i = 1; i < otherBufData.length; i++) {
+    otherBufData[otherBufData.length - i] = (i + 1) % 8;
+  }
+  const buf = Buffer.from(bufData.buffer, bufData.byteOffset);
+  // 0|1 2 3 4 5 6 7 0|1 2 3 4...
+  const otherBuf = Buffer.from(otherBufData.buffer, otherBufData.byteOffset);
+  // 0|0 7 6 5 4 3 2 1|0 7 6 5...
+
+  buf.slice(1, buf.length - 7).swap64();
+  assert.deepStrictEqual(buf.slice(0, otherBuf.length), otherBuf);
 }
-const buf14 = Buffer.from(buf14A.buffer, buf14A.byteOffset);
-// 0|1 2 3 4 5 6 7 0|1 2 3 4...
-const buf15 = Buffer.from(buf15A.buffer, buf15A.byteOffset);
-// 0|0 7 6 5 4 3 2 1|0 7 6 5...
-
-buf14.slice(1, buf14.length - 7).swap64();
-assert.deepStrictEqual(buf14.slice(0, buf15.length), buf15);
-
-// Length assertions
-const re16 = /Buffer size must be a multiple of 16-bits/;
-const re32 = /Buffer size must be a multiple of 32-bits/;
-const re64 = /Buffer size must be a multiple of 64-bits/;
-
-assert.throws(() => Buffer.from(buf3).swap16(), re16);
-assert.throws(() => Buffer.alloc(1025).swap16(), re16);
-assert.throws(() => Buffer.from(buf3).swap32(), re32);
-assert.throws(() => buf3.slice(1, 3).swap32(), re32);
-assert.throws(() => Buffer.alloc(1025).swap32(), re32);
-assert.throws(() => buf3.slice(1, 3).swap64(), re64);
-assert.throws(() => Buffer.alloc(1025).swap64(), re64);