Test 2: Triple Threat

tripleThreat.js

var assert = require('assert');

/********************************
* Return true if the array contains, somewhere, three increasing
* adjacent numbers like .... 4, 5, 6, ... or 23, 24, 25.
*
* See the asserts below for examples of input
* and expected output.
*
* If you have node installed, all you need to do to test
* your code is run: `node tripleThreat.js`. If you see errors,
* it is because the tests below did not pass. Once the
* tests do pass, you will see a log of `Success!`
*
* YOUR CODE BELOW HERE
********************************/


function tripleThreat(array) {
  var i, counter = 0;

  for(i = 1; i < array.length; i++) {

    if(array[i] === (array[i-1] + 1)) {
      counter++;
    } else { counter = 0; }

    if(counter === 2) { return true; }
  }

  counter = 0;

  return false;
}

/********************************
* YOUR CODE ABOVE HERE
********************************/

assert.equal(
  tripleThreat([1, 4, 5, 6, 2]),
  true
);

assert.equal(
  tripleThreat([1, 2, 3]),
  true
);

assert.equal(
  tripleThreat([1, 2, 4, 5, 7, 6, 5, 6, 7, 6]),
  true
);

assert.equal(
  tripleThreat([1, 2, 4, 5, 7, 6, 5, 7, 7, 6]),
  false
);

assert.equal(
  tripleThreat([1,2]),
  false
);

assert.equal(
  tripleThreat([10, 9, 8, -100, -99, -98, 100]),
  true
);

assert.equal(
  tripleThreat([10, 9, 8, -100, -99, 99, 100]),
  false
);

console.log('Success!');