add feature flagged middleware

Author: sarahs

middleware/context.js

@@ -10,7 +10,7 @@ const {
   getPathWithoutLanguage
 } = require('../lib/path-utils')
 const productNames = require('../lib/product-names')
-const warmServer = require('../lib/warm-server')
+const warmServer = process.env.FEATURE_NEW_SITETREE ? require('../lib/warm-server2') : require('../lib/warm-server')
 const featureFlags = Object.keys(require('../feature-flags'))
 const builtAssets = require('../lib/built-asset-urls')
 const searchVersions = require('../lib/search/versions')
@@ -27,7 +27,7 @@ module.exports = async function contextualize (req, res, next) {
   // make feature flag environment variables accessible in layouts
   req.context.process = { env: {} }
   featureFlags.forEach(featureFlagName => {
-    req.context.process.env[featureFlagName] = process.env[featureFlagName]
+    req.context[featureFlagName] = process.env[featureFlagName]
   })
 
   // define each context property explicitly for code-search friendliness

middleware/contextualizers/early-access-links.js

@@ -7,7 +7,7 @@ module.exports = function earlyAccessContext (req, res, next) {
 
   // Get a list of all hidden pages per version
   const earlyAccessPageLinks = uniq(Object.values(req.context.pages)
-    .filter(page => page.hidden && page.relativePath.startsWith('early-access') && page.relativePath !== 'early-access/index.md')
+    .filter(page => page.hidden && page.relativePath.startsWith('early-access') && !page.relativePath.endsWith('index.md'))
     .map(page => page.permalinks)
     .flat())
     // Get links for the current version

middleware/contextualizers/layout.js

@@ -5,16 +5,25 @@ module.exports = function layoutContext (req, res, next) {
 
   let layoutName
 
+  // If this is an index.md that is not the homepage and does not have a defined layout, use `generic-toc`.
+  const usesGenericToc = req.context.page.relativePath.endsWith('index.md') &&
+    req.context.page.documentType !== 'homepage' &&
+    !req.context.page.hidden
+
   if (req.context.page.layout) {
     // Layouts can be specified with a `layout` frontmatter value.
     // Any invalid layout values will be caught by frontmatter schema validation.
     layoutName = req.context.page.layout
-    // A `layout: false` value means use no layout.
   } else if (req.context.page.layout === false) {
+    // A `layout: false` value means use no layout.
     layoutName = ''
-    // If undefined, use either the default layout or the generic-toc layout.
   } else if (req.context.page.layout === undefined) {
-    layoutName = 'default'
+    // For all other files (like articles and the homepage), use the `default` layout.
+    if (process.env.FEATURE_NEW_SITETREE) {
+      layoutName = usesGenericToc ? 'generic-toc' : 'default'
+    } else {
+      layoutName = 'default'
+    }
   }
 
   // Attach to the context object

middleware/index.js

@@ -111,8 +111,19 @@ module.exports = function (app) {
   app.use(instrument('./contextualizers/webhooks'))
   app.use(asyncMiddleware(instrument('./contextualizers/whats-new-changelog')))
   app.use(instrument('./contextualizers/layout'))
-  app.use(asyncMiddleware(instrument('./breadcrumbs')))
-  app.use(asyncMiddleware(instrument('./early-access-breadcrumbs')))
+
+  if (!process.env.FEATURE_NEW_SITETREE) {
+    app.use(asyncMiddleware(instrument('./breadcrumbs')))
+    app.use(asyncMiddleware(instrument('./early-access-breadcrumbs')))
+  }
+
+  if (process.env.FEATURE_NEW_SITETREE) {
+    app.use(instrument('./contextualizers/current-product-tree'))
+    app.use(asyncMiddleware(instrument('./contextualizers/generic-toc')))
+    app.use(asyncMiddleware(instrument('./contextualizers/breadcrumbs')))
+    app.use(asyncMiddleware(instrument('./contextualizers/early-access-breadcrumbs')))
+  }
+
   app.use(asyncMiddleware(instrument('./enterprise-server-releases')))
   app.use(asyncMiddleware(instrument('./dev-toc')))
   app.use(asyncMiddleware(instrument('./featured-links')))