fs: do not emit 'stop' watch event synchronously

Emits 'stop' event for fs.watchFile on process.nextTick
to fix 'maximum call stack size exceeded' error when
`stop` is called synchronously after listener is attached.

PR-URL: https://github.com/nodejs/node/pull/8524
Fixes: https://github.com/nodejs/node/issues/8421
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yorkie Liu <yorkiefixer@gmail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/test/parallel/test-fs-watch-stop-sync.js b/test/parallel/test-fs-watch-stop-sync.js
new file mode 100644
index 0000000000..1444ff6bfd
--- /dev/null
+++ b/test/parallel/test-fs-watch-stop-sync.js
@@ -0,0 +1,9 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const fs = require('fs');
+
+const watch = fs.watchFile(__filename, () => {});
+watch.once('stop', assert.fail);  // Should not trigger.
+watch.stop();
+watch.removeListener('stop', assert.fail);