Completed version of the assessment - not finished within time limits

assessment-completed.js

/* This is not my submitted version.  That version can be found at:
https://gist.github.com/kcoyner/8ddc95ad78b022b1c58363b2ef90e080
I wanted to upload this version as it is 100% complete.  I was able to complete all problems,
just not in the allocated amount of time.  I got hung up on Part 5 on a stupid mistake, and 
Part 6 took me another 15 minutes or so.  Thank you.  Kevin.]
*/

var salesTeam = [{name: {first: 'aleen', last: 'atkins'}, age: 26, sales: '$2314'},
 		{name: {first: 'alvaro', last: 'angelos'}, age: 55, sales: '$1668'},
 		{name: {first: 'denese', last: 'dossett'}, age: 29, sales: '$9248'},
 		{name: {first: 'douglas', last: 'denney'}, age: 53, sales: '$5058'},
 		{name: {first: 'earline', last: 'erickson'}, age: 19, sales: '$18876'},
 		{name: {first: 'herman', last: 'hazell'}, age: 25, sales: '$2746'},
 		{name: {first: 'homer', last: 'hirth'}, age: 26, sales: '$474'},
 		{name: {first: 'hwa', last: 'heidt'}, age: 53, sales: '$9607'},
 		{name: {first: 'hyon', last: 'hampshire'}, age: 46, sales: '$13598'},
 		{name: {first: 'issac', last: 'ingerson'}, age: 45, sales: '$5225'},
 		{name: {first: 'jeraldine', last: 'joplin'}, age: 39, sales: '$2891'},
 		{name: {first: 'jin', last: 'jeffrey'}, age: 17, sales: '$14402'},
 		{name: {first: 'joleen', last: 'jolin'}, age: 45, sales: '$15736'},
 		{name: {first: 'jude', last: 'jarrett'}, age: 53, sales: '$7557'},
 		{name: {first: 'magda', last: 'mireles'}, age: 18, sales: '$1498'},
 		{name: {first: 'mistie', last: 'montealegre'}, age: 31, sales: '$6920'},
 		{name: {first: 'nancy', last: 'napoli'}, age: 49, sales: '$5255'},
 		{name: {first: 'regine', last: 'rohrbaugh'}, age: 33, sales: '$7881'},
 		{name: {first: 'rolando', last: 'riebel'}, age: 35, sales: '$8573'},
 		{name: {first: 'scarlett', last: 'stagg'}, age: 36, sales: '$7126'},
 		{name: {first: 'sherron', last: 'strawn'}, age: 36, sales: '$8848'},
 		{name: {first: 'susan', last: 'shilling'}, age: 29, sales: '$8542'},
 		{name: {first: 'tama', last: 'tworek'}, age: 16, sales: '$9200'},
 		{name: {first: 'tonisha', last: 'taunton'}, age: 41, sales: '$5219'},
 		{name: {first: 'vergie', last: 'villescas'}, age: 25, sales: '$8712'}
];


/** Part 1 **/
function capitalize(salesTeam) {
  //  loop thru the array and change each first and last name
  salesTeam.forEach(member => {
    member.name.first = member.name.first.slice(0,1).toUpperCase() + member.name.first.slice(1);
    member.name.last = member.name.last.slice(0,1).toUpperCase() + member.name.last.slice(1);
  });
}


/** Part 2 **/
function assert(expectedBehavior, descriptionOfCorrectBehavior) {
  if (!expectedBehavior) {
    console.log(descriptionOfCorrectBehavior);
  } else {
    console.log('test passed');
  }
}

capitalize(salesTeam);
assert(JSON.stringify(salesTeam[2].name) === JSON.stringify({first: 'Denese', last: 'Dossett'}), 'it returns capitalized first and last names');


/** Part 3 **/
var averageTeamSales = function (salesTeam) {
  var salesSum = salesTeam.reduce((sum, member) => {
    return sum + salesToNumber(member.sales);
  }, 0);
  return Math.round(salesSum / salesTeam.length);
};

function salesToNumber(salesString){
  return Number.parseInt(salesString.slice(1));
}

console.log(averageTeamSales(salesTeam));


/** Part 4 **/
function assert(expectedBehavior, descriptionOfCorrectBehavior) {
  if (!expectedBehavior) {
    console.log(descriptionOfCorrectBehavior);
  } else {
    console.log('test passed');
  }
}

assert(averageTeamSales(salesTeam) === 7487, 'it should return average sales for the team rounded up');


/** Part 5 **/

highestEarner = function (companies) {
  // check for the highest earner in the sale team
  var salesTeam = companies.sort((a, b) => {
    return salesToNumber(a.sales) - salesToNumber(b.sales);
  });
  var star = (salesTeam.slice(salesTeam.length - 1));
  //  write out that person's info in proper format
  return `${star[0].name.first} ${star[0].name.last}: ${star[0].sales}`;
};

console.log(highestEarner(salesTeam));
assert(highestEarner(salesTeam) === "Earline Erickson: $18876", 'it should return a properly formatted string for the highest earner');



/** Part 6 **/

function filter2(collection, predicate) {
    /*  version made only with each -- see reduce version below */
    var result = [];
    each(collection, function(val){
      if (predicate(val)) {
        result.push(val);
      }
    })
    return result;
}

function filter(collection, predicate) {
  var result = [];
  reduce(each(collection, function(val){
    if (predicate(val)) {
        result.push(val);
    }
  }), predicate, [])
  return result;
}

// DO NOT ADJUST BELOW FUNCTIONS
function reduce(collection, accumulator, initialValue) {
  each(collection, function(val) {
    if (initialValue !== undefined) {
      initialValue = accumulator(initialValue, val);
    } else {
      initialValue = val;
    }
  });
  return initialValue;
}

function each (collection, callback) {
  if (Array.isArray(collection)) {
    for (let i = 0; i < collection.length; i++) {
      callback(collection[i], i, collection);
    }
  } else {
    for (let key in collection) {
      callback(collection[key], key, collection);
    }
  }
}

var arr = [1, 2, 3, 4];
var obj = {
  a: 1,
  b: 2,
  c: 3,
  d: 4
}

function isEven(val) {
  return val % 2 === 0;
}

function isOdd(val) {
  return !isEven(val);
}

var output1 = filter(arr, isEven);
console.log(output1); // --> [2, 4];

var output2 = filter(obj, isOdd);
console.log(output2); // --> [1, 3];