'use strict'; const common = require('../common'); const assert = require('assert'); const path = require('path'); const Buffer = require('buffer').Buffer; const fs = require('fs'); const filepath = path.join(common.fixturesDir, 'x.txt'); const fd = fs.openSync(filepath, 'r'); const expected = 'xyz\n'; const bufferAsync = Buffer.allocUnsafe(expected.length); const bufferSync = Buffer.allocUnsafe(expected.length); fs.read(fd, bufferAsync, 0, expected.length, 0, common.mustCall(function(err, bytesRead) { assert.equal(bytesRead, expected.length); assert.deepStrictEqual(bufferAsync, Buffer.from(expected)); })); var r = fs.readSync(fd, bufferSync, 0, expected.length, 0); assert.deepStrictEqual(bufferSync, Buffer.from(expected)); assert.equal(r, expected.length);