node/test/pummel/test-fs-watch-file-slow.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.

var common = require('../common');
var assert = require('assert');
var path = require('path');
var fs = require('fs');

var FILENAME = path.join(common.tmpDir, 'watch-me');
var TIMEOUT = 1300;

var nevents = 0;

try {
  fs.unlinkSync(FILENAME);
}
catch (e) {
  // swallow
}

fs.watchFile(FILENAME, {interval:TIMEOUT - 250}, function(curr, prev) {
  console.log([curr, prev]);
  switch (++nevents) {
  case 1:
    assert.equal(fs.existsSync(FILENAME), false);
    break;
  case 2:
  case 3:
    assert.equal(fs.existsSync(FILENAME), true);
    break;
  case 4:
    assert.equal(fs.existsSync(FILENAME), false);
    fs.unwatchFile(FILENAME);
    break;
  default:
    assert(0);
  }
});

process.on('exit', function() {
  assert.equal(nevents, 4);
});

setTimeout(createFile, TIMEOUT);

function createFile() {
  console.log('creating file');
  fs.writeFileSync(FILENAME, "test");
  setTimeout(touchFile, TIMEOUT);
}

function touchFile() {
  console.log('touch file');
  fs.writeFileSync(FILENAME, "test");
  setTimeout(removeFile, TIMEOUT);
}

function removeFile() {
  console.log('remove file');
  fs.unlinkSync(FILENAME);
}