test: skip fs.watch on Travis

Fixes: #21310
Refs: https://travis-ci.com/nodejs/node/jobs/142234998
Refs: https://docs.travis-ci.com/user/environment-variables/#default-environment-variables

Author: refack

test/async-hooks/test-fseventwrap.js

@@ -10,6 +10,9 @@ const fs = require('fs');
 if (!common.isMainThread)
   common.skip('Worker bootstrapping works differently -> different async IDs');
 
+if (common.isFSSensitiveCI)
+    common.skip('Skip FS intensive test on sensitive CI.');
+
 const hooks = initHooks();
 
 hooks.enable();

test/common/README.md

@@ -189,6 +189,11 @@ Platform check for Advanced Interactive eXecutive (AIX).
 
 Attempts to 'kill' `pid`
 
+### isFSSensitiveCI
+* [<boolean>]
+
+Check for CI environments that are FS sensitive (e.g. Travis)
+
 ### isFreeBSD
 * [<boolean>]
 

test/common/index.js

@@ -804,3 +804,9 @@ exports.runWithInvalidFD = function(func) {
 
   exports.printSkipMessage('Could not generate an invalid fd');
 };
+
+Object.defineProperty(exports, 'isFSSensitiveCI', {
+  get: function() {
+    return process.env['TRAVIS'] === 'true';
+  }
+});

test/parallel/test-fs-watch-close-when-destroyed.js

@@ -8,6 +8,9 @@ const tmpdir = require('../common/tmpdir');
 const fs = require('fs');
 const path = require('path');
 
+if (common.isFSSensitiveCI)
+    common.skip('Skip FS intensive test on sensitive CI.');
+
 tmpdir.refresh();
 const root = path.join(tmpdir.path, 'watched-directory');
 fs.mkdirSync(root);