benchmark: swap var for let in buffer benchmarks

In benchmark buffers directory this changes for loops using var to let
when it applies for consistency

PR-URL: https://github.com/nodejs/node/pull/28867
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Rich Trott <rtrott@gmail.com>

benchmark/buffers/buffer-base64-decode-wrapped.js

@@ -18,7 +18,7 @@ function main({ charsPerLine, linesCount, n }) {
   const buffer = Buffer.alloc(bytesCount, line, 'base64');
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     buffer.base64Write(data, 0, bytesCount);
   }
   bench.end(n);

benchmark/buffers/buffer-base64-decode.js

@@ -16,6 +16,6 @@ function main({ n, size }) {
   const b = Buffer.allocUnsafe(encodedSize);
   b.write(s, 0, encodedSize, 'base64');
   bench.start();
-  for (var i = 0; i < n; i += 1) b.base64Write(s, 0, s.length);
+  for (let i = 0; i < n; i += 1) b.base64Write(s, 0, s.length);
   bench.end(n);
 }

benchmark/buffers/buffer-bytelength.js

@@ -37,7 +37,7 @@ function main({ n, len, encoding }) {
   }
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     const index = n % strings.length;
     // Go!
     const r = Buffer.byteLength(strings[index], encoding);

benchmark/buffers/buffer-compare-offset.js

@@ -8,12 +8,12 @@ const bench = common.createBenchmark(main, {
 });
 
 function compareUsingSlice(b0, b1, len, iter) {
-  for (var i = 0; i < iter; i++)
+  for (let i = 0; i < iter; i++)
     Buffer.compare(b0.slice(1, len), b1.slice(1, len));
 }
 
 function compareUsingOffset(b0, b1, len, iter) {
-  for (var i = 0; i < iter; i++)
+  for (let i = 0; i < iter; i++)
     b0.compare(b1, 1, len, 1, len);
 }
 

benchmark/buffers/buffer-compare.js

@@ -34,7 +34,7 @@ function main({ n, size }) {
   b1[size - 1] = 'b'.charCodeAt(0);
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     Buffer.compare(b0, b1);
   }
   bench.end(n);

benchmark/buffers/buffer-concat.js

@@ -15,7 +15,7 @@ function main({ n, pieces, pieceSize, withTotalLength }) {
   const totalLength = withTotalLength ? pieces * pieceSize : undefined;
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     Buffer.concat(list, totalLength);
   }
   bench.end(n);

benchmark/buffers/buffer-indexof-number.js

@@ -15,7 +15,7 @@ function main({ n, value }) {
 
   let count = 0;
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     count += aliceBuffer.indexOf(value, 0, undefined);
   }
   bench.end(n);

benchmark/buffers/buffer-indexof.js

@@ -42,7 +42,7 @@ function main({ n, search, encoding, type }) {
   }
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     aliceBuffer.indexOf(search, 0, encoding);
   }
   bench.end(n);

benchmark/buffers/buffer-normalize-encoding.js

@@ -31,7 +31,7 @@ function main({ encoding, n }) {
   const { normalizeEncoding } = require('internal/util');
 
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     normalizeEncoding(encoding);
   }
   bench.end(n);

benchmark/buffers/buffer-read-float.js

@@ -32,7 +32,7 @@ function main({ n, type, endian, value }) {
   buff[`write${type}${endian}`](values[type][value], 0);
 
   bench.start();
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](0);
   }
   bench.end(n);

benchmark/buffers/buffer-read-with-byteLength.js

@@ -23,7 +23,7 @@ function main({ n, buf, type, byteLength }) {
 
   buff.writeDoubleLE(0, 0);
   bench.start();
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](0, byteLength);
   }
   bench.end(n);

benchmark/buffers/buffer-read.js

@@ -33,7 +33,7 @@ function main({ n, buf, type }) {
   buff.writeDoubleLE(0, 0);
   bench.start();
 
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](0);
   }
   bench.end(n);

benchmark/buffers/buffer-slice.js

@@ -13,7 +13,7 @@ const slowBuf = new SlowBuffer(1024);
 function main({ n, type }) {
   const b = type === 'fast' ? buf : slowBuf;
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     b.slice(10, 256);
   }
   bench.end(n);

benchmark/buffers/buffer-swap.js

@@ -27,7 +27,7 @@ function swap(b, n, m) {
 Buffer.prototype.htons = function htons() {
   if (this.length % 2 !== 0)
     throw new RangeError();
-  for (var i = 0; i < this.length; i += 2) {
+  for (let i = 0; i < this.length; i += 2) {
     swap(this, i, i + 1);
   }
   return this;
@@ -46,7 +46,7 @@ Buffer.prototype.htonl = function htonl() {
 Buffer.prototype.htonll = function htonll() {
   if (this.length % 8 !== 0)
     throw new RangeError();
-  for (var i = 0; i < this.length; i += 8) {
+  for (let i = 0; i < this.length; i += 8) {
     swap(this, i, i + 7);
     swap(this, i + 1, i + 6);
     swap(this, i + 2, i + 5);
@@ -58,7 +58,7 @@ Buffer.prototype.htonll = function htonll() {
 function createBuffer(len, aligned) {
   len += aligned ? 0 : 1;
   const buf = Buffer.allocUnsafe(len);
-  for (var i = 1; i <= len; i++)
+  for (let i = 1; i <= len; i++)
     buf[i - 1] = i;
   return aligned ? buf : buf.slice(1);
 }

benchmark/buffers/buffer-tojson.js

@@ -11,7 +11,7 @@ function main({ n, len }) {
   const buf = Buffer.allocUnsafe(len);
 
   bench.start();
-  for (var i = 0; i < n; ++i)
+  for (let i = 0; i < n; ++i)
     buf.toJSON();
   bench.end(n);
 }

benchmark/buffers/buffer-write.js

@@ -89,7 +89,7 @@ function main({ n, buf, type }) {
 function benchBigInt(buff, fn, n) {
   const m = mod[fn];
   bench.start();
-  for (var i = 0n; i !== n; i++) {
+  for (let i = 0n; i !== n; i++) {
     buff[fn](i & m, 0);
   }
   bench.end(Number(n));
@@ -98,7 +98,7 @@ function benchBigInt(buff, fn, n) {
 function benchInt(buff, fn, n) {
   const m = mod[fn];
   bench.start();
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](i & m, 0);
   }
   bench.end(n);
@@ -108,7 +108,7 @@ function benchSpecialInt(buff, fn, n) {
   const m = mod[fn];
   const byte = byteLength[fn];
   bench.start();
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](i & m, 0, byte);
   }
   bench.end(n);
@@ -116,7 +116,7 @@ function benchSpecialInt(buff, fn, n) {
 
 function benchFloat(buff, fn, n) {
   bench.start();
-  for (var i = 0; i !== n; i++) {
+  for (let i = 0; i !== n; i++) {
     buff[fn](i, 0);
   }
   bench.end(n);

benchmark/buffers/buffer-zero.js

@@ -14,6 +14,6 @@ function main({ n, type }) {
   const data = type === 'buffer' ? zeroBuffer : zeroString;
 
   bench.start();
-  for (var i = 0; i < n; i++) Buffer.from(data);
+  for (let i = 0; i < n; i++) Buffer.from(data);
   bench.end(n);
 }

benchmark/buffers/dataview-set.js

@@ -56,7 +56,7 @@ function benchInt(dv, fn, len, le) {
   const m = mod[fn];
   const method = dv[fn];
   bench.start();
-  for (var i = 0; i < len; i++) {
+  for (let i = 0; i < len; i++) {
     method.call(dv, 0, i % m, le);
   }
   bench.end(len);
@@ -65,7 +65,7 @@ function benchInt(dv, fn, len, le) {
 function benchFloat(dv, fn, len, le) {
   const method = dv[fn];
   bench.start();
-  for (var i = 0; i < len; i++) {
+  for (let i = 0; i < len; i++) {
     method.call(dv, 0, i * 0.1, le);
   }
   bench.end(len);