cache /categories.json (#23635)

Author: Peter Bengtsson

middleware/categories-for-support.js

@@ -1,39 +1,59 @@
 import path from 'path'
+
+import { cacheControlFactory } from './cache-control.js'
+
 const renderOpts = { textOnly: true, encodeEntities: true }
 
+const cacheControl = cacheControlFactory(60 * 60 * 24)
+
+// Module-global variable that gets populate once the categoriesForSupport()
+// runs at least once.
+let globalAllCategoriesCache = null
+
 // This middleware exposes a list of all categories and child articles at /categories.json.
 // GitHub Support uses this for internal ZenDesk search functionality.
 export default async function categoriesForSupport(req, res, next) {
   const englishSiteTree = req.context.siteTree.en
 
-  const allCategories = []
+  const allCategories = globalAllCategoriesCache || []
+  if (!allCategories.length) {
+    await Promise.all(
+      Object.keys(englishSiteTree).map(async (version) => {
+        await Promise.all(
+          englishSiteTree[version].childPages.map(async (productPage) => {
+            if (productPage.page.relativePath.startsWith('early-access')) return
+            if (!productPage.childPages) return
 
-  await Promise.all(
-    Object.keys(englishSiteTree).map(async (version) => {
-      await Promise.all(
-        englishSiteTree[version].childPages.map(async (productPage) => {
-          if (productPage.page.relativePath.startsWith('early-access')) return
-          if (!productPage.childPages) return
-
-          await Promise.all(
-            productPage.childPages.map(async (categoryPage) => {
-              // We can't get the rendered titles from middleware/render-tree-titles
-              // here because that middleware only runs on the current version, and this
-              // middleware processes all versions.
-              const name = categoryPage.page.title.includes('{')
-                ? await categoryPage.page.renderProp('title', req.context, renderOpts)
-                : categoryPage.page.title
-
-              allCategories.push({
-                name,
-                published_articles: await findArticlesPerCategory(categoryPage, [], req.context),
+            await Promise.all(
+              productPage.childPages.map(async (categoryPage) => {
+                // We can't get the rendered titles from middleware/render-tree-titles
+                // here because that middleware only runs on the current version, and this
+                // middleware processes all versions.
+                const name = categoryPage.page.title.includes('{')
+                  ? await categoryPage.page.renderProp('title', req.context, renderOpts)
+                  : categoryPage.page.title
+
+                allCategories.push({
+                  name,
+                  published_articles: await findArticlesPerCategory(categoryPage, [], req.context),
+                })
               })
-            })
-          )
-        })
-      )
-    })
-  )
+            )
+          })
+        )
+      })
+    )
+    if (allCategories.length && process.env.NODE_ENV !== 'development') {
+      globalAllCategoriesCache = allCategories
+    }
+  }
+
+  // Cache somewhat aggressively but note that it will be soft-purged
+  // in every prod deployment.
+  cacheControl(res)
+
+  // Undo the cookie setting that CSRF sets.
+  res.removeHeader('set-cookie')
 
   return res.json(allCategories)
 }

tests/rendering/server.js

@@ -247,6 +247,11 @@ describe('server', () => {
     // check for CORS header
     expect(res.headers['access-control-allow-origin']).toBe('*')
 
+    // Check that it can be cached at the CDN
+    expect(res.headers['set-cookie']).toBeUndefined()
+    expect(res.headers['cache-control']).toContain('public')
+    expect(res.headers['cache-control']).toMatch(/max-age=\d+/)
+
     const categories = JSON.parse(res.text)
     expect(Array.isArray(categories)).toBe(true)
     expect(categories.length).toBeGreaterThan(1)