test: remove common.isOSXMojave

common.isOSXMojave was added because it was believed that there was a
bug in macOS Mojave that allowed unprivileged users to bind to
privileged ports. As it turns out, that was a feature not a bug. It is
likely to be in all future versions of macOS. Remove isOSXMojave and
skip appropriate tests based on isOSX.

Refs: https://news.ycombinator.com/item?id=18302380
PR-URL: #25658
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>

Author: Trott

test/common/index.js

@@ -99,8 +99,6 @@ const isOpenBSD = process.platform === 'openbsd';
 const isLinux = process.platform === 'linux';
 const isOSX = process.platform === 'darwin';
 
-const isOSXMojave = isOSX && (os.release().startsWith('18'));
-
 const enoughTestMem = os.totalmem() > 0x70000000; /* 1.75 Gb */
 const cpus = os.cpus();
 const enoughTestCpu = Array.isArray(cpus) &&
@@ -750,7 +748,6 @@ module.exports = {
   isMainThread,
   isOpenBSD,
   isOSX,
-  isOSXMojave,
   isSunOS,
   isWindows,
   localIPv6Hosts,

test/parallel/test-cluster-bind-privileged-port.js

@@ -23,8 +23,8 @@
 const common = require('../common');
 
 // Skip on OS X Mojave. https://github.com/nodejs/node/issues/21679
-if (common.isOSXMojave)
-  common.skip('bypass test for Mojave due to OSX issue');
+if (common.isOSX)
+  common.skip('macOS may allow ordinary processes to use any port');
 
 if (common.isWindows)
   common.skip('not reliable on Windows.');

test/parallel/test-cluster-shared-handle-bind-privileged-port.js

@@ -23,8 +23,8 @@
 const common = require('../common');
 
 // Skip on OS X Mojave. https://github.com/nodejs/node/issues/21679
-if (common.isOSXMojave)
-  common.skip('bypass test for Mojave due to OSX issue');
+if (common.isOSX)
+  common.skip('macOS may allow ordinary processes to use any port');
 
 if (common.isWindows)
   common.skip('not reliable on Windows');