test/parallel/test-fs-readSync-optional-params.js

'use strict';

require('../common');
const fixtures = require('../common/fixtures');
const fs = require('fs');
const assert = require('assert');
const filepath = fixtures.path('x.txt');
const fd = fs.openSync(filepath, 'r');

const expected = Buffer.from('xyz\n');

function runTest(defaultBuffer, options) {
  const result = fs.readSync(fd, defaultBuffer, options);
  assert.strictEqual(result, expected.length);
  assert.deepStrictEqual(defaultBuffer, expected);
}

// Test passing in an empty options object
runTest(Buffer.allocUnsafe(expected.length), { position: 0 });

// Test not passing in any options object
runTest(Buffer.allocUnsafe(expected.length));

// Test passing in options
runTest(Buffer.allocUnsafe(expected.length), { offset: 0,
                                               length: expected.length,
                                               position: 0 });