refactor: extract complex if condition to improve readability (#2105)

* chore: extract complex if condition to improve perf

* chore: better names and more extract

* chore: changed name from isHostname to isValidHostname

Author: anikethsaha

client-src/default/utils/createSocketUrl.js

@@ -32,12 +32,13 @@ function createSocketUrl(resourceQuery) {
   // why do we need this check?
   // hostname n/a for file protocol (example, when using electron, ionic)
   // see: https://github.com/webpack/webpack-dev-server/pull/384
-  if (
+  const isAnyHostname =
     (hostname === '0.0.0.0' || hostname === '::') &&
     self.location.hostname &&
     // eslint-disable-next-line no-bitwise
-    !!~self.location.protocol.indexOf('http')
-  ) {
+    !!~self.location.protocol.indexOf('http');
+
+  if (isAnyHostname) {
     hostname = self.location.hostname;
   }
 
@@ -58,7 +59,8 @@ function createSocketUrl(resourceQuery) {
   let sockPort = urlParts.port;
 
   // eslint-disable-next-line no-undefined
-  if (path !== null && path !== undefined && path !== '/') {
+  const shouldParsePath = path !== null && path !== undefined && path !== '/';
+  if (shouldParsePath) {
     const parsedQuery = querystring.parse(path);
     // all of these sock url params are optionally passed in through
     // resourceQuery, so we need to fall back to the default if

lib/Server.js

@@ -870,13 +870,18 @@ class Server {
     // an IPv6-address in URLs,
     // these are removed from the hostname in url.parse(),
     // so we have the pure IPv6-address in hostname.
-    if (ip.isV4Format(hostname) || ip.isV6Format(hostname)) {
+    // always allow localhost host, for convenience (hostname === 'localhost')
+    // allow hostname of listening address  (hostname === this.hostname)
+    const isValidHostname =
+      ip.isV4Format(hostname) ||
+      ip.isV6Format(hostname) ||
+      hostname === 'localhost' ||
+      hostname === this.hostname;
+
+    if (isValidHostname) {
       return true;
     }
     // always allow localhost host, for convenience
-    if (hostname === 'localhost') {
-      return true;
-    }
     // allow if hostname is in allowedHosts
     if (this.allowedHosts && this.allowedHosts.length) {
       for (let hostIdx = 0; hostIdx < this.allowedHosts.length; hostIdx++) {
@@ -889,23 +894,18 @@ class Server {
         // support "." as a subdomain wildcard
         // e.g. ".example.com" will allow "example.com", "www.example.com", "subdomain.example.com", etc
         if (allowedHost[0] === '.') {
-          // "example.com"
-          if (hostname === allowedHost.substring(1)) {
-            return true;
-          }
-          // "*.example.com"
-          if (hostname.endsWith(allowedHost)) {
+          // "example.com"  (hostname === allowedHost.substring(1))
+          // "*.example.com"  (hostname.endsWith(allowedHost))
+          if (
+            hostname === allowedHost.substring(1) ||
+            hostname.endsWith(allowedHost)
+          ) {
             return true;
           }
         }
       }
     }
 
-    // allow hostname of listening address
-    if (hostname === this.hostname) {
-      return true;
-    }
-
     // also allow public hostname if provided
     if (typeof this.publicHost === 'string') {
       const idxPublic = this.publicHost.indexOf(':');
@@ -955,13 +955,14 @@ class Server {
 
   // send stats to a socket or multiple sockets
   _sendStats(sockets, stats, force) {
-    if (
+    const shouldEmit =
       !force &&
       stats &&
       (!stats.errors || stats.errors.length === 0) &&
       stats.assets &&
-      stats.assets.every((asset) => !asset.emitted)
-    ) {
+      stats.assets.every((asset) => !asset.emitted);
+
+    if (shouldEmit) {
       return this.sockWrite(sockets, 'still-ok');
     }