fix(eslint-plugin-next): respect pageExtensions in no-html-link-for-pages rule

The no-html-link-for-pages rule was using hardcoded regex patterns
/(\.(j|t)sx?)$/ to detect page files, ignoring the pageExtensions
configured in next.config.js.

This change:
- Reads pageExtensions from context.settings.next.pageExtensions
- Passes pageExtensions to getUrlFromPagesDirectories and
  getUrlFromAppDirectory
- Updates parseUrlForPages and parseUrlForAppDir to build dynamic
  regex patterns from the configured extensions
- Defaults to ['jsx', 'js', 'ts', 'tsx'] when no pageExtensions is set

Fixes #53473

Author: RoomWithOutRoof

packages/eslint-plugin-next/src/rules/no-html-link-for-pages.ts

@@ -107,8 +107,18 @@ export default defineRule({
       return {}
     }
 
-    const pageUrls = cachedGetUrlFromPagesDirectories('/', foundPagesDirs)
-    const appDirUrls = cachedGetUrlFromAppDirectory('/', foundAppDirs)
+    // Get pageExtensions from settings, default to ['jsx', 'js', 'ts', 'tsx']
+    const nextSettings: { pageExtensions?: string[] } =
+      context.settings.next || {}
+    const pageExtensions = nextSettings.pageExtensions || [
+      'jsx',
+      'js',
+      'ts',
+      'tsx',
+    ]
+
+    const pageUrls = cachedGetUrlFromPagesDirectories('/', foundPagesDirs, pageExtensions)
+    const appDirUrls = cachedGetUrlFromAppDirectory('/', foundAppDirs, pageExtensions)
     const allUrlRegex = [...pageUrls, ...appDirUrls]
 
     return {

packages/eslint-plugin-next/src/utils/url.ts

@@ -8,25 +8,31 @@ const fsReadDirSyncCache = {}
 /**
  * Recursively parse directory for page URLs.
  */
-function parseUrlForPages(urlprefix: string, directory: string) {
+function parseUrlForPages(
+  urlprefix: string,
+  directory: string,
+  pageExtensions: string[]
+) {
   fsReadDirSyncCache[directory] ??= fs.readdirSync(directory, {
     withFileTypes: true,
   })
   const res = []
+  // Build a regex from the configured pageExtensions
+  const extPattern = new RegExp(`(\\.(?:${pageExtensions.join('|')}))$`)
+  const indexPattern = new RegExp(`^index(\\.(?:${pageExtensions.join('|')}))$`)
+
   fsReadDirSyncCache[directory].forEach((dirent) => {
-    // TODO: this should account for all page extensions
-    // not just js(x) and ts(x)
-    if (/(\.(j|t)sx?)$/.test(dirent.name)) {
-      if (/^index(\.(j|t)sx?)$/.test(dirent.name)) {
+    if (extPattern.test(dirent.name)) {
+      if (indexPattern.test(dirent.name)) {
         res.push(
-          `${urlprefix}${dirent.name.replace(/^index(\.(j|t)sx?)$/, '')}`
+          `${urlprefix}${dirent.name.replace(indexPattern, '')}`
         )
       }
-      res.push(`${urlprefix}${dirent.name.replace(/(\.(j|t)sx?)$/, '')}`)
+      res.push(`${urlprefix}${dirent.name.replace(extPattern, '')}`)
     } else {
       const dirPath = path.join(directory, dirent.name)
       if (dirent.isDirectory() && !dirent.isSymbolicLink()) {
-        res.push(...parseUrlForPages(urlprefix + dirent.name + '/', dirPath))
+        res.push(...parseUrlForPages(urlprefix + dirent.name + '/', dirPath, pageExtensions))
       }
     }
   })
@@ -36,24 +42,31 @@ function parseUrlForPages(urlprefix: string, directory: string) {
 /**
  * Recursively parse app directory for URLs.
  */
-function parseUrlForAppDir(urlprefix: string, directory: string) {
+function parseUrlForAppDir(
+  urlprefix: string,
+  directory: string,
+  pageExtensions: string[]
+) {
   fsReadDirSyncCache[directory] ??= fs.readdirSync(directory, {
     withFileTypes: true,
   })
   const res = []
+  // Build a regex from the configured pageExtensions
+  const extPattern = new RegExp(`(\\.(?:${pageExtensions.join('|')}))$`)
+  const pagePattern = new RegExp(`^page(\\.(?:${pageExtensions.join('|')}))$`)
+  const layoutPattern = new RegExp(`^layout(\\.(?:${pageExtensions.join('|')}))$`)
+
   fsReadDirSyncCache[directory].forEach((dirent) => {
-    // TODO: this should account for all page extensions
-    // not just js(x) and ts(x)
-    if (/(\.(j|t)sx?)$/.test(dirent.name)) {
-      if (/^page(\.(j|t)sx?)$/.test(dirent.name)) {
-        res.push(`${urlprefix}${dirent.name.replace(/^page(\.(j|t)sx?)$/, '')}`)
-      } else if (!/^layout(\.(j|t)sx?)$/.test(dirent.name)) {
-        res.push(`${urlprefix}${dirent.name.replace(/(\.(j|t)sx?)$/, '')}`)
+    if (extPattern.test(dirent.name)) {
+      if (pagePattern.test(dirent.name)) {
+        res.push(`${urlprefix}${dirent.name.replace(pagePattern, '')}`)
+      } else if (!layoutPattern.test(dirent.name)) {
+        res.push(`${urlprefix}${dirent.name.replace(extPattern, '')}`)
       }
     } else {
       const dirPath = path.join(directory, dirent.name)
       if (dirent.isDirectory(dirPath) && !dirent.isSymbolicLink()) {
-        res.push(...parseUrlForPages(urlprefix + dirent.name + '/', dirPath))
+        res.push(...parseUrlForAppDir(urlprefix + dirent.name + '/', dirPath, pageExtensions))
       }
     }
   })
@@ -136,13 +149,16 @@ export function normalizeAppPath(route: string) {
  */
 export function getUrlFromPagesDirectories(
   urlPrefix: string,
-  directories: string[]
+  directories: string[],
+  pageExtensions: string[] = ['jsx', 'js', 'ts', 'tsx']
 ) {
   return Array.from(
     // De-duplicate similar pages across multiple directories.
     new Set(
       directories
-        .flatMap((directory) => parseUrlForPages(urlPrefix, directory))
+        .flatMap((directory) =>
+          parseUrlForPages(urlPrefix, directory, pageExtensions)
+        )
         .map(
           // Since the URLs are normalized we add `^` and `$` to the RegExp to make sure they match exactly.
           (url) => `^${normalizeURL(url)}$`
@@ -156,13 +172,14 @@ export function getUrlFromPagesDirectories(
 
 export function getUrlFromAppDirectory(
   urlPrefix: string,
-  directories: string[]
+  directories: string[],
+  pageExtensions: string[] = ['jsx', 'js', 'ts', 'tsx']
 ) {
   return Array.from(
     // De-duplicate similar pages across multiple directories.
     new Set(
       directories
-        .map((directory) => parseUrlForAppDir(urlPrefix, directory))
+        .map((directory) => parseUrlForAppDir(urlPrefix, directory, pageExtensions))
         .flat()
         .map(
           // Since the URLs are normalized we add `^` and `$` to the RegExp to make sure they match exactly.