url: ensure search property is consistently null vs empty

PR-URL: #13606
Fixes: #13404
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

lib/url.js

@@ -196,7 +196,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
           this.query = this.search.slice(1);
         }
       } else if (parseQueryString) {
-        this.search = '';
+        this.search = null;
         this.query = Object.create(null);
       }
       return this;
@@ -389,7 +389,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
     }
   } else if (parseQueryString) {
     // no query string, but parseQueryString still requested
-    this.search = '';
+    this.search = null;
     this.query = Object.create(null);
   }
 

test/parallel/test-url-parse-query.js

@@ -36,7 +36,7 @@ const parseTestsWithQueryString = {
     host: 'example.com',
     hostname: 'example.com',
     query: createWithNoPrototype(),
-    search: '',
+    search: null,
     pathname: '/',
     path: '/'
   },
@@ -48,7 +48,7 @@ const parseTestsWithQueryString = {
     port: null,
     hostname: null,
     hash: null,
-    search: '',
+    search: null,
     query: createWithNoPrototype(),
     pathname: '/example',
     path: '/example',