test.js

var truncate = require('./truncate');

exports['should truncate text with given length'] = function (t) {
  var input, expect, actual;

  input = null;
  actual = truncate(input, 3);
  expect = '';
  t.strictEqual(expect, actual);

  input = '';
  actual = truncate(input, 3);
  expect = '';
  t.strictEqual(expect, actual);

  input = 'hello';
  actual = truncate(input, 3);
  expect = 'hel…';
  t.strictEqual(expect, actual);

  input = 'I am not sure what I am talking about';
  actual = truncate(input, 10);
  expect = 'I am not s…';
  t.strictEqual(expect, actual);
  t.done();
};

exports['should keep url safe'] = function (t) {
  var input, expect, actual;
  input = 'Hey http://distilleryimage8.s3.amazonaws.com/719bf2329ddd11e28c3122000aa80097_7.jpg';
  actual = truncate(input, 4);
  expect = 'Hey …';
  t.strictEqual(expect, actual);

  input = 'Hey http://distilleryimage8.s3.amazonaws.com/719bf2329ddd11e28c3122000aa80097_7.jpg';
  actual = truncate(input, 5);
  expect = 'Hey http://distilleryimage8.s3.amazonaws.com/719bf2329ddd11e28c3122000aa80097_7.jpg';
  t.strictEqual(expect, actual);

  input = 'http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product/ http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product2/';
  actual = truncate(input, 96);
  expect = 'http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product/…';
  t.strictEqual(expect, actual);

  input = 'http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product/ http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product2/';
  actual = truncate(input, 100);
  expect = 'http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product/ http://successfulsoftware.net/2013/03/19/the-brutal-truth-about-marketing-your-software-product2/';
  t.strictEqual(expect, actual);

  input = 'Hey http://distilleryimage8.s3.amazonaws.com/719bf2329ddd11e28c3122000aa80097_7.jpg';
  actual = truncate(input, 5);
  expect = 'Hey http://distilleryimage8.s3.amazonaws.com/719bf2329ddd11e28c3122000aa80097_7.jpg';
  t.strictEqual(expect, actual);

  input = 'Hey http://hehe.com plop http://plop.com';
  actual = truncate(input, 6);
  expect = 'Hey http://hehe.com…';
  t.strictEqual(expect, actual);

  input = 'Hey http://hehe.com plop http://plop.com';
  actual = truncate(input, 22);
  expect = 'Hey http://hehe.com pl…';
  t.strictEqual(expect, actual);

  input = 'Hey http://hehe.com plop http://plop.com';
  actual = truncate(input, 25);
  expect = 'Hey http://hehe.com plop …';
  t.strictEqual(expect, actual);

  input = 'Hey http://hehe.com plop http://plop.com';
  actual = truncate(input, 26);
  t.strictEqual(input, actual);

  t.done();
};

exports['should cut off huge URLs for safety'] = function (t) {
  var input, expect, actual, longString;
  longString = "a".repeat(301);
  input = 'Hey mailto:' + longString + '@' + longString + '.com';
  actual = truncate(input, 5);
  expect = 'Hey m…';
  t.strictEqual(expect, actual);

  // Just above the limit, should get chopped
  longString = "a".repeat(3000 - 'https://'.length + 1);
  input = 'Hey https://' + longString;
  actual = truncate(input, 5);
  expect = 'Hey h…';
  t.strictEqual(expect, actual);

  // Right at the limit, should be retained
  longString = "a".repeat(3000 - 'https://'.length);
  input = 'Hey https://' + longString;
  actual = truncate(input, 5);
  expect = input;
  t.strictEqual(expect, actual);

  // Still retain the long URL even if there's text after the long URL
  input = 'Hey https://' + longString + " other text";
  actual = truncate(input, 5);
  expect = expect + '…'
  t.strictEqual(expect, actual);

  t.done();
}

exports['Not vulnerable to REDOS'] = function (t) {

  var prefix, pump, suffix, nPumps, attackString; // for evil input
  var input, actual, expect; // input to truncate()
  var before, elapsed; // timing

  /* URL_REGEX */
  prefix = '-@w--w--';
  pump = 'ww--';
  suffix = '';
  nPumps = 20000;

  attackString = prefix;
  for (var i = 0; i < nPumps; i++) {
    attackString += pump;
  }
  attackString += suffix;

  before = process.hrtime();
  input = 'Hey ' + attackString;
  actual = truncate(input, 4);
  expect = 'Hey …';
  t.strictEqual(expect, actual);
  elapsed = process.hrtime(before);

  t.equals(elapsed[0], 0); // Should take < 1 second
  t.done();
};