fs: add 'close' event to FSWatcher

PR-URL: https://github.com/nodejs/node/pull/19900
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

3 files changed, 13 insertions, 0 deletions

diff --git a/doc/api/fs.md b/doc/api/fs.md
index 69138b6ac4..bf4261c15c 100644
--- a/doc/api/fs.md
+++ b/doc/api/fs.md
@@ -329,6 +329,13 @@ added: v0.5.8
 
 Emitted when an error occurs while watching the file.
 
+### Event: 'close'
+<!-- YAML
+added: REPLACEME
+-->
+
+Emitted when the watcher stops watching for changes.
+
 ### watcher.close()
 <!-- YAML
 added: v0.5.8
diff --git a/lib/fs.js b/lib/fs.js
index 6b80af3b63..6c8417030b 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -1387,8 +1387,13 @@ FSWatcher.prototype.close = function() {
     return;
   }
   this._handle.close();
+  process.nextTick(emitCloseNT, this);
 };
 
+function emitCloseNT(self) {
+  self.emit('close');
+}
+
 fs.watch = function(filename, options, listener) {
   if (typeof options === 'function') {
     listener = options;
diff --git a/test/parallel/test-fs-watch.js b/test/parallel/test-fs-watch.js
index 94a81799e5..ffa82e52c7 100644
--- a/test/parallel/test-fs-watch.js
+++ b/test/parallel/test-fs-watch.js
@@ -54,6 +54,7 @@ for (const testCase of cases) {
     }
     assert.fail(err);
   });
+  watcher.on('close', common.mustCall());
   watcher.on('change', common.mustCall(function(eventType, argFilename) {
     if (interval) {
       clearInterval(interval);