nodejs/test/parallel/test-file-write-stream2.js

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';
require('../common');
const assert = require('assert');

const fs = require('fs');

const tmpdir = require('../common/tmpdir');


const filepath = tmpdir.resolve('write.txt');

const EXPECTED = '012345678910';

const cb_expected = 'write open drain write drain close ';
let cb_occurred = '';

let countDrains = 0;


process.on('exit', function() {
  removeTestFile();
  if (cb_occurred !== cb_expected) {
    console.log('  Test callback events missing or out of order:');
    console.log(`    expected: ${cb_expected}`);
    console.log(`    occurred: ${cb_occurred}`);
    assert.strictEqual(
      cb_occurred, cb_expected,
      `events missing or out of order: "${cb_occurred}" !== "${cb_expected}"`);
  } else {
    console.log('ok');
  }
});

function removeTestFile() {
  try {
    fs.unlinkSync(filepath);
  } catch {
    // Continue regardless of error.
  }
}


tmpdir.refresh();

// Drain at 0, return false at 10.
const file = fs.createWriteStream(filepath, {
  highWaterMark: 11
});

file.on('open', function(fd) {
  console.error('open');
  cb_occurred += 'open ';
  assert.strictEqual(typeof fd, 'number');
});

file.on('drain', function() {
  console.error('drain');
  cb_occurred += 'drain ';
  ++countDrains;
  if (countDrains === 1) {
    console.error('drain=1, write again');
    assert.strictEqual(fs.readFileSync(filepath, 'utf8'), EXPECTED);
    console.error(`ondrain write ret= ${file.write(EXPECTED)}`);
    cb_occurred += 'write ';
  } else if (countDrains === 2) {
    console.error('second drain, end');
    assert.strictEqual(fs.readFileSync(filepath, 'utf8'), EXPECTED + EXPECTED);
    file.end();
  }
});

file.on('close', function() {
  cb_occurred += 'close ';
  assert.strictEqual(file.bytesWritten, EXPECTED.length * 2);
  file.write('should not work anymore', (err) => {
    assert.ok(err.message.includes('write after end'));
  });
});

for (let i = 0; i < 11; i++) {
  const ret = file.write(String(i));
  console.error(`${i} ${ret}`);

  // Return false when i hits 10
  assert.strictEqual(ret, i !== 10);
}
cb_occurred += 'write ';