test-fs-watch-file-enoent-after-deletion.js

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';
const common = require('../common');

// Make sure the deletion event gets reported in the following scenario:
// 1. Watch a file.
// 2. The initial stat() goes okay.
// 3. Something deletes the watched file.
// 4. The second stat() fails with ENOENT.

// The second stat() translates into the first 'change' event but a logic error
// stopped it from getting emitted.
// https://github.com/nodejs/node-v0.x-archive/issues/4027

const assert = require('assert');
const path = require('path');
const fs = require('fs');

const tmpdir = require('../common/tmpdir');
tmpdir.refresh();

const filename = path.join(tmpdir.path, 'watched');
fs.writeFileSync(filename, 'quis custodiet ipsos custodes');

fs.watchFile(filename, { interval: 50 }, common.mustCall(function(curr, prev) {
  assert.strictEqual(prev.nlink, 1);
  assert.strictEqual(curr.nlink, 0);
  fs.unwatchFile(filename);
}));

setTimeout(fs.unlinkSync, common.platformTimeout(300), filename);