FIRST -
function makeStudentsReport(data) {
  // your code here
  function objectValue(obj) {
    return obj.name + ': ' + obj.grade;
  }
  return data.map(objectValue);
}


/* From here down, you are not expected to
   understand.... for now :)

   Nothing to see here!

*/


// tests

function testIt() {

  const testData = [
    {name: 'Jane Doe', grade: 'A'},
    {name: 'John Dough', grade: 'B'},
    {name: 'Jill Do', grade: 'A'}
  ];

  const expectations = [
    'Jane Doe: A',
    'John Dough: B',
    'Jill Do: A'
  ];

  const results = makeStudentsReport(testData);

  if (!(results && results instanceof Array)) {
    console.error(
      'FAILURE: `makeStudentsReport` must return an array');
    return
  }
  if (results.length !== testData.length) {
    console.error(
      'FAILURE: test data had length of ' + testData.length +
      ' but `makeStudentsReport` returned array of length ' + results.length);
    return
  }
  for (let i=0; i < expectations.length; i++) {
    let expect = expectations[i];
    if (!results.find(function(item) {
      return item === expect;
    })) {
      console.error(
        'FAILURE: `makeStudentsReport` is not ' +
        'producing expected strings'
      );
      return
    }
  }
  console.log('SUCCESS: `makeStudentsReport` is working');
}

testIt();


SECOND -
const studentData = [
  {
    name: 'Tim',
    status: 'Current student',
    course: 'Biology'
  },
  {
    name: 'Sue',
    status: 'Withdrawn',
    course: 'Mathematics'
  },
  {
    name: 'Liz',
    status: 'On leave',
    course: 'Computer science'
  }
];

function enrollInSummerSchool(students) {
  // your code here
  let newArray = students;
  for (let i = 0; i < newArray.length; i++) {
   newArray[i].status = 'In Summer school';
  }
  return newArray;
}


/* From here down, you are not expected to understand.... for now :)
  Nothing to see here!

*/

// tests


function testIt() {
    var testData = [
        {
            name: 'Burt',
            status: 'Playing hooky',
            course: 'Biology'
        },
        {
            name: 'Melanie',
            status: 'Sick',
            course: 'Mathematics'
        },
        {
            name: 'Leonard',
            status: 'AWOL',
            course: 'Computer science'
        }
    ];

    var results = enrollInSummerSchool(testData);

    if (!(results && results instanceof Array)) {
        console.error('FAILURE: `enrollSummerSchool` must return an array');
        return
    }
    var result = testData.every(function(student) {
            var match = results.find(function(_student) {
                    return (
                    _student.name === student.name &&
                    _student.course === student.course &&
                    _student.status.toLowerCase() === 'in summer school'
                    );
                }
            );
            return match !== undefined;
        }
    );
    if (!result) {
        console.error(
            'FAILURE: `enrollSummerSchool` should return ' +
            'original key/value pairs for each student, and ' +
            'update `status` to "In Summer school": ' + JSON.stringify(results));
    } else {
          console.info('SUCCESS: `enrollSummerSchool` is working');
    }
}

testIt();


THIRD -
// you can pass in `scratchData` to test out `findByid`
// your function
const scratchData = [
  {id: 22, foo: 'bar'},
  {id: 28, foo: 'bizz'},
  {id: 19, foo: 'bazz'}
];

function findById(items, idNum) {
 // your code here
 for (let i = 0; i < items.length; i++) {
   if (idNum === items[i].id) {
     return items[i];
   }
 }
}


//

function testIt() {
  const testData = [
    {id: 1, foo: 'bar'},
    {id: 2, foo: 'bizz'},
    {id: 3, bang: 'boo'}
  ];
  const result = findById(testData, 3);
  if (!(result && result !== null && typeof result === 'object')) {
    console.error('`findById` must return an object');
    return
  }
  if (result.id !== 3) {
    console.error(
      'Asked for item with id of `3` but got back one with id of ' +
      result.id
    );
    return
  }
  if (result.bang !== 'boo') {
    console.error('Expected all key/value pairs from target object to be returned');
    return
  }
  console.log('SUCCESS: `findByid` is working');
}

testIt();


FOURTH -
// running the function with `objectA` and `expectedKeys`
// should return `true`
const objectA = {
  id: 2,
  name: 'Jane Doe',
  age: 34,
  city: 'Chicago'
}

// running the function with `objectB` and `expectedKeys`
// should return `false`
const objectB = {
  id: 3,
  age: 33,
  city: 'Peoria'
}

const expectedKeys = [
  'id', 'name', 'age', 'city'
];

function validateKeys(object, expectedKeys) {
 // your code here
let currentKeys = Object.keys(object);
if (currentKeys.length !== expectedKeys.length) {
  return false;
}

for (let i = 0; i < expectedKeys.length; i++) {
  if (currentKeys[i] !== expectedKeys[i]){
    return false;
  } else {
    return true;
  }
}
}
/* From here down, you are not expected to
   understand.... for now :)


   Nothing to see here!

*/



function testIt() {
  const objectA = {
    id: 2,
    name: 'Jane Doe',
    age: 34,
    city: 'Chicago'
  }

  const objectB = {
    id: 3,
    age: 33,
    city: 'Peoria'
  }

  const objectC = {
    id: 9,
    name: 'Billy Bear',
    age: 62,
    city: 'Milwaukee',
    status: 'paused'
  }


  const objectD = {
    foo: 2,
    bar: 'Jane Doe',
    bizz: 34,
    bang: 'Chicago'
  }

  const expectedKeys = [
    'id', 'name', 'age', 'city'
  ];

  if (typeof validateKeys(objectA, expectedKeys) !== 'boolean') {
    console.error(
      'FAILURE: validateKeys should return a boolean value');
    return;
  }


  if (!validateKeys(objectA, expectedKeys)) {
    console.error(
      `FAILURE: running validateKeys with the following object and keys
      should return true but returned false:
      Object: ${JSON.stringify(objectA)}
      Expected keys: ${expectedKeys}`
    )
    return;
  }

  if (validateKeys(objectB, expectedKeys)) {
   console.error(
      `FAILURE: running validateKeys with the following object and keys
      should return false but returned true:
      Object: ${JSON.stringify(objectB)}
      Expected keys: ${expectedKeys}`
    )
    return;
  }

  if (validateKeys(objectC, expectedKeys)) {
   console.error(
      `FAILURE: running validateKeys with the following object and keys
      should return false but returned true:
      Object: ${JSON.stringify(objectC)}
      Expected keys: ${expectedKeys}`
    )
    return;
  }

  if (validateKeys(objectD, expectedKeys)) {
   console.error(
      `FAILURE: running validateKeys with the following object and keys
      should return false but returned true:
      Object: ${JSON.stringify(objectD)}
      Expected keys: ${expectedKeys}`
    )
    return;
  }

  console.log('SUCCESS: validateKeys is working');
}

testIt()