fs: add recursive watch for linux

doc/api/fs.md

@@ -4320,6 +4320,9 @@ The `atime` and `mtime` arguments follow these rules:
 <!-- YAML
 added: v0.5.10
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/45098
+ description: Added recursive support for Linux, AIX and IBMi.
  - version:
  - v15.9.0
  - v14.17.0
@@ -4377,10 +4380,6 @@ the returned{fs.FSWatcher}.
 The `fs.watch` API is not 100% consistent across platforms, and is
 unavailable in some situations.
 
-The recursive option is only supported on macOS and Windows.
-An `ERR_FEATURE_UNAVAILABLE_ON_PLATFORM` exception will be thrown
-when the option is used on a platform that does not support it.
-
 On Windows, no events will be emitted if the watched directory is moved or
 renamed. An `EPERM` error is reported when the watched directory is deleted.
 

lib/fs.js

@@ -57,6 +57,7 @@ const{
 
 const pathModule = require('path');
 const{isArrayBufferView } = require('internal/util/types');
+const nonNativeWatcher = require('internal/fs/recursive_watch');
 
 // We need to get the statValues from the binding at the callsite since
 // it's re-initialized after deserialization.
@@ -68,7 +69,6 @@ const{
  codes:{
  ERR_FS_FILE_TOO_LARGE,
  ERR_INVALID_ARG_VALUE,
- ERR_FEATURE_UNAVAILABLE_ON_PLATFORM,
  },
  AbortError,
  uvErrmapGet,
@@ -163,7 +163,6 @@ let FileWriteStream;
 const isWindows = process.platform === 'win32'
 const isOSX = process.platform === 'darwin'
 
-
 function showTruncateDeprecation(){
  if (truncateWarn){
  process.emitWarning(
@@ -2297,13 +2296,22 @@ function watch(filename, options, listener){
 
  if (options.persistent === undefined) options.persistent = true;
  if (options.recursive === undefined) options.recursive = false;
- if (options.recursive && !(isOSX || isWindows))
- throw new ERR_FEATURE_UNAVAILABLE_ON_PLATFORM('watch recursively');
- const watcher = new watchers.FSWatcher();
- watcher[watchers.kFSWatchStart](filename,
- options.persistent,
- options.recursive,
- options.encoding);
+
+ let watcher;
+
+ // TODO(anonrig): Remove this when/if libuv supports it.
+ // As of November 2022, libuv does not support recursive file watch on all platforms,
+ // e.g. Linux due to the limitations of inotify.
+ if (options.recursive && !isOSX && !isWindows){
+ watcher = new nonNativeWatcher.FSWatcher(options);
+ watcher[watchers.kFSWatchStart](filename);
+ } else{
+ watcher = new watchers.FSWatcher();
+ watcher[watchers.kFSWatchStart](filename,
+ options.persistent,
+ options.recursive,
+ options.encoding);
+ }
 
  if (listener){
  watcher.addListener('change', listener);

lib/internal/fs/promises.js

@@ -88,7 +88,8 @@ const{
 } = require('internal/util');
 const{EventEmitterMixin } = require('internal/event_target');
 const{StringDecoder } = require('string_decoder');
-const{watch } = require('internal/fs/watchers');
+const{kFSWatchStart, watch } = require('internal/fs/watchers');
+const nonNativeWatcher = require('internal/fs/recursive_watch');
 const{isIterable } = require('internal/streams/utils');
 const assert = require('internal/assert');
 
@@ -120,6 +121,7 @@ const getDirectoryEntriesPromise = promisify(getDirents);
 const validateRmOptionsPromise = promisify(validateRmOptions);
 
 const isWindows = process.platform === 'win32'
+const isOSX = process.platform === 'darwin'
 
 let cpPromises;
 function lazyLoadCpPromises(){
@@ -917,6 +919,26 @@ async function readFile(path, options){
  return handleFdClose(readFileHandle(fd, options), fd.close);
 }
 
+async function* _watch(filename, options = kEmptyObject){
+ validateObject(options, 'options');
+
+ if (options.recursive != null){
+ validateBoolean(options.recursive, 'options.recursive');
+
+ // TODO(anonrig): Remove this when/if libuv supports it.
+ // As of November 2022, libuv does not support recursive file watch on all platforms,
+ // e.g. Linux due to the limitations of inotify.
+ if (options.recursive && !isOSX && !isWindows){
+ const watcher = new nonNativeWatcher.FSWatcher(options);
+ await watcher[kFSWatchStart](filename);
+ yield* watcher;
+ return;
+ }
+ }
+
+ yield* watch(filename, options);
+}
+
 module.exports ={
  exports:{
  access,
@@ -947,7 +969,7 @@ module.exports ={
  writeFile,
  appendFile,
  readFile,
- watch,
+ watch: !isOSX && !isWindows ? _watch : watch,
  constants,
  },