'use strict'; var common = require('../common'); var assert = require('assert'); var path = require('path'), fs = require('fs'), filepath = path.join(common.tmpDir, 'large.txt'), fd = fs.openSync(filepath, 'w+'), offset = 5 * 1024 * 1024 * 1024, // 5GB message = 'Large File'; fs.truncateSync(fd, offset); assert.equal(fs.statSync(filepath).size, offset); var writeBuf = Buffer.from(message); fs.writeSync(fd, writeBuf, 0, writeBuf.length, offset); var readBuf = Buffer.allocUnsafe(writeBuf.length); fs.readSync(fd, readBuf, 0, readBuf.length, offset); assert.equal(readBuf.toString(), message); fs.readSync(fd, readBuf, 0, 1, 0); assert.equal(readBuf[0], 0); var exceptionRaised = false; try { fs.writeSync(fd, writeBuf, 0, writeBuf.length, 42.000001); } catch (err) { console.log(err); exceptionRaised = true; assert.equal(err.message, 'Not an integer'); } assert.ok(exceptionRaised); fs.close(fd); process.on('exit', function() { fs.unlinkSync(filepath); });