url: detect hostname more reliably in url.parse()

Based on existing tests and code comments, url.parse() is expected to
treat any URL containing user@host as having a hostname. However, it
turns out this behavior relies on the URL having a hash which is
surprising, to put it mildly. Detect the host even without the hash.

PR-URL: nodejs#41031
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Myles Borins <[email protected]>

lib/url.js

@@ -187,6 +187,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
   // Back slashes before the query string get converted to forward slashes
   // See: https://code.google.com/p/chromium/issues/detail?id=25916
   let hasHash = false;
+  let hasAt = false;
   let start = -1;
   let end = -1;
   let rest = '';
@@ -219,6 +220,9 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
     // Only convert backslashes while we haven't seen a split character
     if (!split) {
       switch (code) {
+        case CHAR_AT:
+          hasAt = true;
+          break;
         case CHAR_HASH:
           hasHash = true;
         // Fall through
@@ -259,7 +263,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
     }
   }
 
-  if (!slashesDenoteHost && !hasHash) {
+  if (!slashesDenoteHost && !hasHash && !hasAt) {
     // Try fast path regexp
     const simplePath = simplePathPattern.exec(rest);
     if (simplePath) {

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

@@ -946,7 +946,37 @@ const parseTests = {
     pathname: '/',
     path: '/',
     href: 'wss://www.example.com/'
-  }
+  },
+
+  '//[email protected]/everybody-to-the-limit': {
+    protocol: null,
+    slashes: true,
+    auth: 'fhqwhgads',
+    host: 'example.com',
+    port: null,
+    hostname: 'example.com',
+    hash: null,
+    search: null,
+    query: null,
+    pathname: '/everybody-to-the-limit',
+    path: '/everybody-to-the-limit',
+    href: '//[email protected]/everybody-to-the-limit'
+  },
+
+  '//[email protected]/everybody#to-the-limit': {
+    protocol: null,
+    slashes: true,
+    auth: 'fhqwhgads',
+    host: 'example.com',
+    port: null,
+    hostname: 'example.com',
+    hash: '#to-the-limit',
+    search: null,
+    query: null,
+    pathname: '/everybody',
+    path: '/everybody',
+    href: '//[email protected]/everybody#to-the-limit'
+  },
 };
 
 for (const u in parseTests) {