doc: list macOS as supporting filename argument

also added regression tests PR-URL: #13111Fixes: #13108 Reviewed-By: Refael Ackermann <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Alexey Orlenko <[email protected]>

Author: Chris Young

doc/api/fs.md

@@ -2297,10 +2297,10 @@ this improves the usability of file watching. This is expected behavior.
 
 <!--type=misc-->
 
-Providing `filename` argument in the callback is only supported on Linux and
-Windows. Even on supported platforms, `filename` is not always guaranteed to
-be provided. Therefore, don't assume that `filename` argument is always
-provided in the callback, and have some fallback logic if it is null.
+Providing `filename` argument in the callback is only supported on Linux,
+macOS, Windows, and AIX. Even on supported platforms, `filename` is not always
+guaranteed to be provided. Therefore, don't assume that `filename` argument is
+always provided in the callback, and have some fallback logic if it is null.
 
 ```js
 fs.watch('somedir', (eventType, filename) =>{

test/parallel/test-fs-watchfile.js

@@ -63,3 +63,21 @@ fs.watchFile(enoentFile,{interval: 0}, common.mustCall(function(curr, prev){
 fs.unwatchFile(enoentFile);
 }
 },2));
+
+// Watch events should callback with a filename on supported systems
+if(common.isLinux||common.isOSX||common.isWindows||common.isAix){
+constdir=common.tmpDir+'/watch';
+
+fs.mkdir(dir,common.mustCall(function(err){
+if(err)assert.fail(err);
+
+fs.watch(dir,common.mustCall(function(eventType,filename){
+this._handle.close();
+assert.strictEqual(filename,'foo.txt');
+}));
+
+fs.writeFile(`${dir}/foo.txt`,'foo',common.mustCall(function(err){
+if(err)assert.fail(err);
+}));
+}));
+}