test: fix flaky test-fs-watch-encoding on OS X

PR-URL: #7356
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Santiago Gimeno <[email protected]>

Author: Trott

Diff for: test/parallel/test-fs-watch-encoding.js

@@ -1,54 +1,75 @@
 'use strict';
 
+// This test is a bit more complicated than it ideally needs to be to work
+// around issues on OS X and SmartOS.
+//
+// On OS X, watch events are subject to peculiar timing oddities such that an
+// event might fire out of order. The synchronous refreshing of the tmp
+// directory might trigger an event on the watchers that are instantiated after
+// it!
+//
+// On SmartOS, the watch events fire but the filename is null.
+
 const common = require('../common');
 const fs = require('fs');
 const path = require('path');
-const assert = require('assert');
-
-if (common.isFreeBSD) {
-  common.skip('Test currently not working on FreeBSD');
-  return;
-}
 
 common.refreshTmpDir();
 
 const fn = '新建文夹件.txt';
 const a = path.join(common.tmpDir, fn);
 
+const watchers = new Set();
+
+function registerWatcher(watcher) {
+  watchers.add(watcher);
+}
+
+function unregisterWatcher(watcher) {
+  watcher.close();
+  watchers.delete(watcher);
+  if (watchers.size === 0) {
+    clearInterval(interval);
+  }
+}
+
 const watcher1 = fs.watch(
   common.tmpDir,
   {encoding: 'hex'},
   (event, filename) => {
-    if (filename)
-      assert.equal(filename, 'e696b0e5bbbae69687e5a4b9e4bbb62e747874');
-    watcher1.close();
+    if (['e696b0e5bbbae69687e5a4b9e4bbb62e747874', null].includes(filename))
+      done(watcher1);
   }
 );
+registerWatcher(watcher1);
 
 const watcher2 = fs.watch(
   common.tmpDir,
   (event, filename) => {
-    if (filename)
-      assert.equal(filename, fn);
-    watcher2.close();
+    if ([fn, null].includes(filename))
+      done(watcher2);
   }
 );
+registerWatcher(watcher2);
 
 const watcher3 = fs.watch(
   common.tmpDir,
   {encoding: 'buffer'},
   (event, filename) => {
-    if (filename) {
-      assert(filename instanceof Buffer);
-      assert.equal(filename.toString('utf8'), fn);
-    }
-    watcher3.close();
+    if (filename instanceof Buffer && filename.toString('utf8') === fn)
+      done(watcher3);
+    else if (filename === null)
+      done(watcher3);
   }
 );
+registerWatcher(watcher3);
 
-const fd = fs.openSync(a, 'w+');
-fs.closeSync(fd);
+const done = common.mustCall(unregisterWatcher, watchers.size);
 
-process.on('exit', () => {
-  fs.unlink(a);
-});
+// OS X and perhaps other systems can have surprising race conditions with
+// file events. So repeat the operation in case it is missed the first time.
+const interval = setInterval(() => {
+  const fd = fs.openSync(a, 'w+');
+  fs.closeSync(fd);
+  fs.unlinkSync(a);
+}, common.platformTimeout(100));