readline: multiple code cleanups

Variety of code maintenance updates, cleanups

PR-URL: #12755
Reviewed-By: Anna Henningsen <[email protected]>

Author: jasnell

lib/readline.js

@@ -27,25 +27,32 @@
 
 'use strict';
 
+const { debug, inherits } = require('util');
+const Buffer = require('buffer').Buffer;
+const EventEmitter = require('events');
+const {
+  emitKeys,
+  getStringWidth,
+  isFullWidthCodePoint,
+  stripVTControlCharacters
+} = require('internal/readline');
+
 const kHistorySize = 30;
 const kMincrlfDelay = 100;
 const kMaxcrlfDelay = 2000;
+// \r\n, \n, or \r followed by something other than \n
+const lineEnding = /\r?\n|\r(?!\n)/;
 
-const util = require('util');
-const debug = util.debuglog('readline');
-const inherits = util.inherits;
-const Buffer = require('buffer').Buffer;
-const EventEmitter = require('events');
-const internalReadline = require('internal/readline');
-const emitKeys = internalReadline.emitKeys;
-const getStringWidth = internalReadline.getStringWidth;
-const isFullWidthCodePoint = internalReadline.isFullWidthCodePoint;
-const stripVTControlCharacters = internalReadline.stripVTControlCharacters;
+const KEYPRESS_DECODER = Symbol('keypress-decoder');
+const ESCAPE_DECODER = Symbol('escape-decoder');
+
+// GNU readline library - keyseq-timeout is 500ms (default)
+const ESCAPE_CODE_TIMEOUT = 500;
 
 
 function createInterface(input, output, completer, terminal) {
   return new Interface(input, output, completer, terminal);
-};
+}
 
 
 function Interface(input, output, completer, terminal) {
@@ -373,8 +380,6 @@ Interface.prototype.write = function(d, key) {
   this.terminal ? this._ttyWrite(d, key) : this._normalWrite(d);
 };
 
-// \r\n, \n, or \r followed by something other than \n
-const lineEnding = /\r?\n|\r(?!\n)/;
 Interface.prototype._normalWrite = function(b) {
   if (b === undefined) {
     return;
@@ -961,12 +966,6 @@ Interface.prototype._ttyWrite = function(s, key) {
  * accepts a readable Stream instance and makes it emit "keypress" events
  */
 
-const KEYPRESS_DECODER = Symbol('keypress-decoder');
-const ESCAPE_DECODER = Symbol('escape-decoder');
-
-// GNU readline library - keyseq-timeout is 500ms (default)
-const ESCAPE_CODE_TIMEOUT = 500;
-
 function emitKeypressEvents(stream, iface) {
   if (stream[KEYPRESS_DECODER]) return;
   var StringDecoder = require('string_decoder').StringDecoder; // lazy load