test/parallel/test-fs-truncate-fd.js

'use strict';
const common = require('../common');
const assert = require('assert');
const path = require('path');
const fs = require('fs');
const tmpdir = require('../common/tmpdir');
const tmp = tmpdir.path;
tmpdir.refresh();
const filename = path.resolve(tmp, 'truncate-file.txt');

fs.writeFileSync(filename, 'hello world', 'utf8');
const fd = fs.openSync(filename, 'r+');

const msg = 'Using fs.truncate with a file descriptor is deprecated.' +
' Please use fs.ftruncate with a file descriptor instead.';


common.expectWarning('DeprecationWarning', msg, 'DEP0081');
fs.truncate(fd, 5, common.mustCall((err) => {
  assert.ok(!err);
  assert.strictEqual(fs.readFileSync(filename, 'utf8'), 'hello');
}));

process.on('exit', () => {
  fs.closeSync(fd);
  fs.unlinkSync(filename);
  console.log('ok');
});