querystring: 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/internal/url.js

@@ -27,7 +27,9 @@ const {
 CHAR_LOWERCASE_A,
 CHAR_LOWERCASE_Z,
 }=require('internal/constants');
-constquerystring=require('querystring');
+
+// Lazy loaded for startup performance.
+letquerystring;
 
 const{ platform }=process;
 constisWindows=platform==='win32';
@@ -771,8 +773,10 @@ function parseParams(qs) {
 }elseif(encodeCheck>0){
 // eslint-disable-next-line no-extra-boolean-cast
 if(!!isHexTable[code]){
-if(++encodeCheck===3)
+if(++encodeCheck===3){
+querystring=require('querystring');
 encoded=true;
+}
 }else{
 encodeCheck=0;
 }

lib/url.js

@@ -94,7 +94,6 @@ const slashedProtocol = {
 'file': true,
 'file:': true
 };
-constquerystring=require('querystring');
 const{
 CHAR_SPACE,
 CHAR_TAB,
@@ -133,6 +132,9 @@ const {
 CHAR_AT,
 }=require('internal/constants');
 
+// Lazy loaded for startup performance.
+letquerystring;
+
 functionurlParse(url,parseQueryString,slashesDenoteHost){
 if(urlinstanceofUrl)returnurl;
 
@@ -233,6 +235,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
 if(simplePath[2]){
 this.search=simplePath[2];
 if(parseQueryString){
+if(querystring===undefined)querystring=require('querystring');
 this.query=querystring.parse(this.search.slice(1));
 }else{
 this.query=this.search.slice(1);
@@ -422,6 +425,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
 this.query=rest.slice(questionIdx+1,hashIdx);
 }
 if(parseQueryString){
+if(querystring===undefined)querystring=require('querystring');
 this.query=querystring.parse(this.query);
 }
 }elseif(parseQueryString){
@@ -584,8 +588,10 @@ Url.prototype.format = function format() {
 }
 }
 
-if(this.query!==null&&typeofthis.query==='object')
+if(this.query!==null&&typeofthis.query==='object'){
+if(querystring===undefined)querystring=require('querystring');
 query=querystring.stringify(this.query);
+}
 
 varsearch=this.search||(query&&('?'+query))||'';