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

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

@@ -21,6 +21,50 @@ const pagesDirWarning = execOnce((pagesDirs) => {
 // Prevent multiple blocking IO requests that have already been calculated.
 const fsExistsSyncCache = {}
 
+/**
+ * Attempts to read pageExtensions from next.config.js or next.config.mjs
+ * in the project root directory.
+ */
+function getPageExtensions(context: any): string[] | undefined {
+  const rootDirs = getRootDirs(context)
+  const configNames = [
+    'next.config.js',
+    'next.config.mjs',
+    'next.config.ts',
+    'next.config.cjs',
+  ]
+
+  for (const rootDir of rootDirs) {
+    for (const configName of configNames) {
+      const configPath = path.join(rootDir, configName)
+      if (fs.existsSync(configPath)) {
+        try {
+          const content = fs.readFileSync(configPath, 'utf8')
+          // Match pageExtensions assignment: pageExtensions: [...] or "pageExtensions": [...]
+          const match = content.match(/pageExtensions\s*:\s*\[([^\]]+)\]/)
+          if (match) {
+            // Extract quoted strings from the array
+            const extensions: string[] = []
+            const arrayContent = match[1]
+            const quoteMatches = arrayContent.match(/['"](\w+)['"]/g)
+            if (quoteMatches) {
+              for (const qm of quoteMatches) {
+                extensions.push(qm.slice(1, -1))
+              }
+            }
+            if (extensions.length > 0) {
+              return extensions
+            }
+          }
+        } catch {
+          // Ignore read errors, continue to next config
+        }
+      }
+    }
+  }
+  return undefined
+}
+
 const memoize = <T = any>(fn: (...args: any[]) => T) => {
   const cache = {}
   return (...args: any[]): T => {
@@ -107,8 +151,19 @@ export default defineRule({
       return {}
     }
 
-    const pageUrls = cachedGetUrlFromPagesDirectories('/', foundPagesDirs)
-    const appDirUrls = cachedGetUrlFromAppDirectory('/', foundAppDirs)
+    // Get pageExtensions from next.config.js if available
+    const pageExtensions = getPageExtensions(context)
+
+    const pageUrls = cachedGetUrlFromPagesDirectories(
+      '/',
+      foundPagesDirs,
+      pageExtensions
+    )
+    const appDirUrls = cachedGetUrlFromAppDirectory(
+      '/',
+      foundAppDirs,
+      pageExtensions
+    )
     const allUrlRegex = [...pageUrls, ...appDirUrls]
 
     return {

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

@@ -5,28 +5,48 @@ import * as fs from 'fs'
 // Prevent multiple blocking IO requests that have already been calculated.
 const fsReadDirSyncCache = {}
 
+/**
+ * Gets the default page extensions (js, jsx, ts, tsx).
+ */
+function getDefaultPageExtensions(): string[] {
+  return ['js', 'jsx', 'ts', 'tsx']
+}
+
+/**
+ * Builds a regex pattern from page extensions.
+ */
+function buildExtensionPattern(pageExtensions: string[]): RegExp {
+  const exts = pageExtensions.length > 0 ? pageExtensions : getDefaultPageExtensions()
+  const pattern = exts.map((ext) => ext.replace('.', '\\.')).join('|')
+  return new RegExp(`\\.(${pattern})$`)
+}
+
 /**
  * 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 extPattern = buildExtensionPattern(pageExtensions || getDefaultPageExtensions())
+  const extMatcher = new RegExp(`(${extPattern.source})$`)
   const res = []
   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)) {
-        res.push(
-          `${urlprefix}${dirent.name.replace(/^index(\.(j|t)sx?)$/, '')}`
-        )
+    if (extMatcher.test(dirent.name)) {
+      const baseName = dirent.name.replace(extMatcher, '')
+      if (/^index$/.test(baseName)) {
+        res.push(`${urlprefix}`)
+      } else {
+        res.push(`${urlprefix}${baseName}/`)
       }
-      res.push(`${urlprefix}${dirent.name.replace(/(\.(j|t)sx?)$/, '')}`)
     } 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 +56,29 @@ 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 extPattern = buildExtensionPattern(pageExtensions || getDefaultPageExtensions())
+  const extMatcher = new RegExp(`(${extPattern.source})$`)
   const res = []
   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?)$/, '')}`)
+    if (extMatcher.test(dirent.name)) {
+      const baseName = dirent.name.replace(extMatcher, '')
+      if (/^page$/.test(baseName)) {
+        res.push(`${urlprefix}`)
+      } else if (!/^layout$/.test(baseName)) {
+        res.push(`${urlprefix}${baseName}/`)
       }
     } else {
       const dirPath = path.join(directory, dirent.name)
       if (dirent.isDirectory(dirPath) && !dirent.isSymbolicLink()) {
-        res.push(...parseUrlForPages(urlprefix + dirent.name + '/', dirPath))
+        res.push(...parseUrlForPages(urlprefix + dirent.name + '/', dirPath, pageExtensions))
       }
     }
   })
@@ -136,13 +161,14 @@ export function normalizeAppPath(route: string) {
  */
 export function getUrlFromPagesDirectories(
   urlPrefix: string,
-  directories: string[]
+  directories: string[],
+  pageExtensions?: string[]
 ) {
   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 +182,14 @@ export function getUrlFromPagesDirectories(
 
 export function getUrlFromAppDirectory(
   urlPrefix: string,
-  directories: string[]
+  directories: string[],
+  pageExtensions?: string[]
 ) {
   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.