os: lazy loaded

PR-URL: #20567
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

Author: BridgeAR

lib/assert.js

@@ -33,7 +33,7 @@ const { codes: {
 const{ AssertionError, errorCache }=require('internal/assert');
 const{ openSync, closeSync, readSync }=require('fs');
 const{ inspect,types: { isPromise, isRegExp }}=require('util');
-const{EOL}=require('os');
+const{EOL}=require('internal/constants');
 const{ NativeModule }=require('internal/bootstrap/loaders');
 
 // Escape control characters but not \n and \t to keep the line breaks and

lib/internal/constants.js

@@ -1,5 +1,7 @@
 'use strict';
 
+constisWindows=process.platform==='win32';
+
 module.exports={
 // Alphabet chars.
 CHAR_UPPERCASE_A: 65,/* A */
@@ -45,4 +47,6 @@ module.exports = {
 // Digits
 CHAR_0: 48,/* 0 */
 CHAR_9: 57,/* 9 */
+
+EOL: isWindows ? '\r\n' : '\n'
 };

lib/internal/tty.js

@@ -22,9 +22,7 @@
 
 'use strict';
 
-const{ release }=require('os');
-
-constOSRelease=release().split('.');
+letOSRelease;
 
 constCOLORS_2=1;
 constCOLORS_16=4;
@@ -75,6 +73,11 @@ function getColorDepth(env = process.env) {
 }
 
 if(process.platform==='win32'){
+// Lazy load for startup performance.
+if(OSRelease===undefined){
+const{ release }=require('os');
+OSRelease=release().split('.');
+}
 // Windows 10 build 10586 is the first Windows release that supports 256
 // colors. Windows 10 build 14931 is the first release that supports
 // 16m/TrueColor.