add new module

lib/find-page-in-version.js

@@ -0,0 +1,22 @@
+const findPage = require('./find-page')
+const getApplicableVersions = require('./get-applicable-versions')
+
+module.exports = function findPageInVersion (href, pages, redirects, languageCode, version, isDotcomOnly = false) {
+  // findPage() will throw an error if an English page can't be found
+  const page = findPage(href, pages, redirects, languageCode)
+  if (!page) return null
+
+  // if the link is on the homepage, return the page as soon as it's found
+  if (version === 'homepage') return page
+
+  // if the link is dotcom-only, return the page as soon as it's found
+  if (isDotcomOnly) return page
+
+  // otherwise, get the versions that the found page is available in
+  const applicableVersions = getApplicableVersions(page.versions, page.fullPath)
+
+  // return null if the found page's available versions do not include the specified version
+  if (!applicableVersions.includes(version)) return null
+
+  return page
+}