In path utils, speed up version lookups (#16915)

Author: heiskr

lib/path-utils.js

@@ -6,6 +6,8 @@ const allProducts = require('./all-products')
 const allVersions = require('./all-versions')
 const { getNewVersionedPath } = require('./old-versions-utils')
 
+const supportedVersions = new Set(Object.keys(allVersions))
+
 // construct appropriate versioned path for any given HREF
 function getVersionedPathWithoutLanguage (href, version) {
   // start clean without language code or trailing slash
@@ -24,7 +26,7 @@ function getVersionedPathWithoutLanguage (href, version) {
 
   // if the version found is not a currently supported version...
   let productObjectFromPath
-  if (!Object.keys(allVersions).includes(versionFromPath)) {
+  if (!supportedVersions.has(versionFromPath)) {
     // first check if the first segment is instead a current product;
     // example: /admin/foo or /desktop/foo
     productObjectFromPath = allProducts[versionFromPath]