Compute category versions from combining versions of children (#45685)

src/fixtures/fixtures/content/get-started/versioning/index.md

@@ -2,10 +2,11 @@
 title: Versioning
 intro: 'Testing of pages that only available in *some* versions'
 versions:
-  fpt: '*'
-  ghes: '*'
-  ghae: '*'
-  ghec: '*'
+  # Note that these here are wrong!
+  # They deliberately don't match what's set in the versions
+  # within the children.
+  ghes: '>=3.99'
+  ghec: '<1.0'
 children:
   - /only-fpt
   - /only-ghec

src/fixtures/tests/versioning.js

@@ -1,4 +1,3 @@
-import { expect } from '@jest/globals'
 import { getDOM, head } from '#src/tests/helpers/e2etest.js'
 import { supported } from '#src/versions/lib/enterprise-server-releases.js'
 
@@ -47,6 +46,33 @@ describe('article versioning', () => {
   })
 })
 
+describe('category versioning', () => {
+  test('category page work in all children versions', async () => {
+    {
+      // Note that in the `versions:` of get-started/versioning/index.md
+      // it *lacks* fpt. It's a deliberate pretend omission/mistake.
+      // But clearly the page works.
+      const res = await head('/en/get-started/versioning')
+      expect(res.statusCode).toBe(200)
+    }
+    {
+      // The actual version number of get-started/versioning/index.md
+      // does not specify this version of ghes, it still works.
+      const res = await head('/en/enterprise-server@latest/get-started/versioning')
+      expect(res.statusCode).toBe(302)
+      expect(res.headers.location).toMatch(
+        /\/en\/enterprise-server@[\d.]+\/get-started\/versioning/,
+      )
+    }
+    {
+      // The actual version number of get-started/versioning/index.md
+      // does not specify this version of ghec, it still works.
+      const res = await head('/en/enterprise-cloud@latest/get-started/versioning')
+      expect(res.statusCode).toBe(200)
+    }
+  })
+})
+
 describe('home page versioning', () => {
   test('invalid language and valid version', async () => {
     // Don't use 'latest' here because that will trigger a redirect

src/frame/lib/page-data.js

@@ -6,6 +6,7 @@ import createTree from './create-tree.js'
 import nonEnterpriseDefaultVersion from '#src/versions/lib/non-enterprise-default-version.js'
 import readFileContents from './read-file-contents.js'
 import Page from './page.js'
+import Permalink from './permalink.js'
 import frontmatterSchema from './frontmatter.js'
 import { correctTranslatedContentStrings } from '#src/languages/lib/correct-translation-content.js'
 
@@ -42,6 +43,7 @@ export async function loadUnversionedTree(languagesOnly = null) {
   }
   const unversionedTree = {}
   unversionedTree.en = await createTree(path.join(languages.en.dir, 'content'))
+  setCategoryApplicableVersions(unversionedTree.en)
 
   const languagesValues = Object.entries(languages)
     .filter(([language]) => {
@@ -67,6 +69,52 @@ export async function loadUnversionedTree(languagesOnly = null) {
   return unversionedTree
 }
 
+function setCategoryApplicableVersions(tree) {
+  // Now that the tree has been fully computed, we can for any node that
+  // is a category page, re-set its `.applicableVersions` and `.permalinks`
+  // based on the union set of all its immediate children's
+  // `.applicableVersions`.
+  for (const childPage of tree.childPages) {
+    if (childPage.page.relativePath.endsWith('index.md')) {
+      const combinedApplicableVersions = []
+      let moreThanOneChild = false
+      for (const childChildPage of childPage.childPages || []) {
+        for (const version of childChildPage.page.applicableVersions) {
+          if (!combinedApplicableVersions.includes(version)) {
+            combinedApplicableVersions.push(version)
+          }
+        }
+        setCategoryApplicableVersions(childPage)
+        moreThanOneChild = true
+      }
+      if (
+        // Some landing pages have no children at all.
+        // For example the search/index.md page. With no children,
+        // the combined applicableVersions would be [].
+        moreThanOneChild &&
+        !equalSets(
+          new Set(childPage.page.applicableVersions),
+          new Set(combinedApplicableVersions),
+        ) &&
+        !childPage.page.relativePath.startsWith('early-access')
+      ) {
+        const newPermalinks = Permalink.derive(
+          childPage.page.languageCode,
+          childPage.page.relativePath,
+          childPage.page.title,
+          combinedApplicableVersions,
+        )
+        childPage.page.permalinks = newPermalinks
+        childPage.page.applicableVersions = combinedApplicableVersions
+      }
+    }
+  }
+}
+
+function equalSets(setA, setB) {
+  return setA.size === setB.size && [...setA].every((x) => setB.has(x))
+}
+
 async function translateTree(dir, langObj, enTree) {
   const item = {}
   const enPage = enTree.page

src/frame/middleware/find-page.js

@@ -23,7 +23,20 @@ export default async function findPage(
 
   let page = req.context.pages[req.pagePath]
   if (page && isDev && englishPrefixRegex.test(req.pagePath)) {
+    // The .applicableVersions and .permalinks properties are computed
+    // when the page is read in from disk. But when the initial tree
+    // was created at startup, the pages in the tree were mutated
+    // based on their context. For example, a category page's versions
+    // is based on looping through all its children's versions.
+    const reuseOldVersions = page.relativePath.endsWith('index.md')
+    const oldApplicableVersions = page.applicableVersions
+    const oldPermalinks = page.permalinks
+
     page = await rereadByPath(req.pagePath, contentRoot, req.context.currentVersion)
+    if (reuseOldVersions) {
+      page.applicableVersions = oldApplicableVersions
+      page.permalinks = oldPermalinks
+    }
 
     // This can happen if the page we just re-read has changed which
     // versions it's available in (the `versions` frontmatter) meaning

src/links/scripts/rendered-content-link-checker.js

@@ -578,7 +578,9 @@ async function processPermalink(core, permalink, page, pageMap, redirects, opts,
   try {
     html = await renderInnerHTML(page, permalink)
   } catch (error) {
-    console.warn(`The error happened trying to render ${page.relativePath}`)
+    console.warn(
+      `The error happened trying to render ${page.relativePath} (permalink: ${permalink.href})`,
+    )
     throw error
   }
   const $ = cheerio.load(html, { xmlMode: true })