var common = require('../common'); var assert = require('assert'); var path = require('path'); var fs = require('fs'); var tmp = common.tmpDir; if (!fs.existsSync(tmp)) fs.mkdirSync(tmp); var filename = path.resolve(tmp, 'truncate-file.txt'); var success = 0; fs.writeFileSync(filename, 'hello world', 'utf8'); var fd = fs.openSync(filename, 'r+'); fs.truncate(fd, 5, function(err) { assert.ok(!err); assert.equal(fs.readFileSync(filename, 'utf8'), 'hello'); success++; }); process.on('exit', function() { fs.closeSync(fd); fs.unlinkSync(filename); assert.equal(success, 1); console.log('ok'); });