JavaScript Coding Katas with Unit Tests

Kata: Filter API Data

Implement the filterApiData function in filter-api-data.js with the following requirements in mind.

• The first parameter apiData will be an array that includes objects
• The objects can have different keys
• The second parameter mandatoryKeys is a array that includes all keys that an object (from the apiData array) should have to pass the filter test
• Return an array with only the objects that include all keys from the mandatoryKeys array

Filter Api Data Examples

const data = [{ id: 1, price: 100 }, { price: 50 }];

const filteredData = filterApiData(data, ["id"]);

console.log(filteredData); // [{id: 1, price: 100}]

const data = [
  { id: 1, price: 100 },
  { id: 2, title: "" },
  { id: 3, price: 50 },
];

const filteredData = filterApiData(data, ["id", "price"]);

console.log(filteredData); // [{ id: 1, price: 100 }, { id:3, price: 50}]

Kata: Sum App

Implement the SumApp class in sum-app.js with the following requirements in mind.

• The sumApp class should have a property numbers which is an array
• The sumApp class should have a method addNumber(n) which will add the given number to the numbers array
• The sumApp class should have a method getSum() which return the sum of all numbers added to the numbers array
  • The getSum() method should return 0 if no numbers have been added to the numbers array
• The sumApp class should have a method reset() which should delete all numbers previously added to the numbers array

Sum App Example

const sumApp = new SumApp();

sumApp.addNumber(1);
sumApp.addNumber(2);

console.log(sumApp.numbers.length); // 2

console.log(sumApp.getSum()); // 3

sumApp.reset();

console.log(sumApp.numbers.length); // 0
console.log(sumApp.getSum()); // 0

Zip Strings

Implement a zipStrings function in zip-strings.js with the following requirements in mind.

• The zipStrings function receives two string parameters
• The zipStrings function should return one string where the characters of both parameters are merged using the zip procedure (Reißverschlussverfahren)
• Merge the strings as shown in the Zip Strings Example code

Zip Strings Example

console.log(zipStrings("abc", "123")); // "a1b2c3"

console.log(zipStrings("abc", "1")); // "a1bc"

console.log(zipStrings("a", "123")); // "a123"

console.log(zipStrings("", "123")); // "123"

console.log(zipStrings("abc", "")); // "abc"

Extract Class Name

TODO

Extract Class Name Example

console.log(extractClassName("Live-Session Class 2022 September")); // "2022-09"

console.log(extractClassName("Live-Session Class 2022 März")); // "2022-03"

console.log(extractClassName("Live-Session Class 2022 Maerz")); // "2022-03"

console.log(extractClassName("Live-Session 2022 April")); // null

console.log(extractClassName("Live-Session Class 2 X")); // null

console.log(extractClassName("Live-Session Class 2022 Y")); // null

console.log(extractClassName("Live-Session Class 22 April")); // null