test-watch-file.js

// Copyright Joyent, Inc. and other Node contributors.
//
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// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
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// 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,
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// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

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

tmpdir.refresh();
const f = path.join(tmpdir.path, 'x.txt');
fs.closeSync(fs.openSync(f, 'w'));

let changes = 0;
function watchFile() {
  fs.watchFile(f, (curr, prev) => {
    changes++;
    assert.notDeepStrictEqual(curr.mtime, prev.mtime);
    fs.unwatchFile(f);
    watchFile();
    fs.unwatchFile(f);
  });
}

watchFile();


const fd = fs.openSync(f, 'w+');
fs.writeSync(fd, 'xyz\n');
fs.closeSync(fd);

process.on('exit', function() {
  assert.ok(changes > 0);
});