'use strict'; const common = require('../common'); const fixtures = require('../common/fixtures'); const fs = require('fs'); const read = require('util').promisify(fs.read); const assert = require('assert'); const filepath = fixtures.path('x.txt'); const fd = fs.openSync(filepath, 'r'); const expected = Buffer.from('xyz\n'); const defaultBufferAsync = Buffer.alloc(16384); read(fd, {}) .then(function({ bytesRead, buffer }) { assert.strictEqual(bytesRead, expected.length); assert.deepStrictEqual(defaultBufferAsync.length, buffer.length); }) .then(common.mustCall());