Replace use of forEach() and Array#indexOf()

index.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const encodings = require('./lib/encodings')
+const rangeOptions = new Set(['lt', 'gt', 'lte', 'gte'])
 
 module.exports = Codec
 
@@ -62,19 +63,19 @@ Codec.prototype.encodeBatch = function (ops, opts) {
   })
 }
 
-const ltgtKeys = ['lt', 'gt', 'lte', 'gte']
-
 Codec.prototype.encodeLtgt = function (ltgt) {
   const ret = {}
-  Object.keys(ltgt).forEach((key) => {
+
+  for (const key of Object.keys(ltgt)) {
     if (key === 'start' || key === 'end') {
       throw new Error('Legacy range options ("start" and "end") have been removed')
     }
 
-    ret[key] = ltgtKeys.indexOf(key) > -1
+    ret[key] = rangeOptions.has(key)
       ? this.encodeKey(ltgt[key], ltgt)
       : ltgt[key]
-  })
+  }
+
   return ret
 }
 

lib/encodings.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const Buffer = require('buffer').Buffer
+const { Buffer } = require('buffer')
 
 exports.utf8 = exports['utf-8'] = {
   encode: function (data) {
@@ -46,7 +46,7 @@ const bufferEncodings = [
   'utf-16le'
 ]
 
-bufferEncodings.forEach(function (type) {
+for (const type of bufferEncodings) {
   exports[type] = {
     encode: function (data) {
       return isBinary(data) ? data : Buffer.from(data, type)
@@ -57,7 +57,7 @@ bufferEncodings.forEach(function (type) {
     buffer: true,
     type: type
   }
-})
+}
 
 function identity (value) {
   return value