AUTOTITLE on anchor links should error (#35823)

lib/render-content/plugins/rewrite-local-links.js

@@ -11,6 +11,8 @@ import removeFPTFromPath from '../../remove-fpt-from-path.js'
 import readJsonFile from '../../read-json-file.js'
 import findPage from '../../find-page.js'
 
+const isProd = process.env.NODE_ENV === 'production'
+
 const supportedPlans = new Set(Object.values(allVersions).map((v) => v.plan))
 const externalRedirects = readJsonFile('./lib/redirects/external-sites.json')
 
@@ -38,13 +40,20 @@ function setDataAttributesOnCurrentPath(path) {
 }
 
 // Matches any <a> tags with an href that starts with `/`
-const matcher = (node) =>
+const matcherInternalLinks = (node) =>
   node.type === 'element' &&
   node.tagName === 'a' &&
   node.properties &&
   node.properties.href &&
   node.properties.href.startsWith('/')
 
+const matcherAnchorLinks = (node) =>
+  node.type === 'element' &&
+  node.tagName === 'a' &&
+  node.properties &&
+  node.properties.href &&
+  node.properties.href.startsWith('#')
+
 // Content authors write links like `/some/article/path`, but they need to be
 // rewritten on the fly to match the current language and page version
 export default function rewriteLocalLinks(context) {
@@ -55,7 +64,7 @@ export default function rewriteLocalLinks(context) {
   return async (tree) => {
     const promises = []
 
-    visit(tree, matcher, (node) => {
+    visit(tree, matcherInternalLinks, (node) => {
       const newHref = getNewHref(node, currentLanguage, currentVersion)
       if (newHref) {
         node.properties.href = newHref
@@ -83,6 +92,21 @@ export default function rewriteLocalLinks(context) {
       }
     })
 
+    if (!isProd) {
+      // This runs when doing local preview, link checker tests, or
+      // running a script like `update-internal-links.js`.
+      visit(tree, matcherAnchorLinks, (node) => {
+        for (const child of node.children || []) {
+          if (child.value && AUTOTITLE.test(child.value)) {
+            throw new Error(
+              `Found anchor link with text AUTOTITLE ('${node.properties.href}'). ` +
+                'Update the anchor link with text that is not AUTOTITLE.'
+            )
+          }
+        }
+      })
+    }
+
     if (promises.length) {
       await Promise.all(promises)
     }