Technical Assignment (JS)

Getting Started

1. Clone this repository git clone https://github.com/cube-planning/technical-assignment-js.git
2. cd technical-assignment-js
3. npm install

Assignment

There are no constraints when implementing the solutions to the following sections, but please take a moment to read through each section carefully before you get started.

The submission will be evaluated by the following criteria:

• Reliability - The solution works as intended and is bug-free
• Readability - The code is easy to read and understand
• Testability - Unit tests are of high quality and cover all cases
• Reusability - The code is written in a modular and reusable way

Let us know if you have any questions!

Sections

• Section 1
• Section 2
• Section 3

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Section 1:

Create a custom implementation of the reduce function.

So that the following expression:

reduce((a, v) => a + v)([1, 2, 3]);

Produces the following output:

6;

Requirements

• Should execute a reducer function for each element in an array
• Should return a single value
• Should accept all parameters defined in Array.reduce
• Should work for an array of different data types
• Should not execute over an empty array
• Should not mutate the original array

Section 2:

Create a custom implementation of the filter function.

So that the following expression:

filter((x) => x !== "a")(["a", "b", "c", "d"]);

Produces the following output:

["b", "c", "d"];

Requirements

• Should create a new array with elements that pass a test provided by the function
• Should accept all parameters defined in Array.filter
• Should work for an array of different data types
• Should not execute over an empty array
• Should not mutate the original array

Section 3:

Create a function that takes any number of functions and invokes them from right to left

myFunc(func1, func2)(args);

Using this function, create another function that when given the following input:

[
  {
    1: [1, 3, 5, 7, 9],
  },
  {
    1: [0, 2, 4, 6, 8],
  },
  {
    2: [5, 5, 9],
  },
  {
    2: [5, 4, 3, 2, 1],
  },
];

Produces the following output:

{
  1: 45,
  2: 24
}

Requirements

• Should create a new array that consolidates the elements by object key
• Should add all unique array values for each object key
• Should not execute over an empty array
• Should not mutate the original array
• Use your custom implementations from the previous sections

Submit Your Assignment

When you're done, push your code to a private GitHub repository under your username (e.g. github.com/your-username/technical-assignment-js). Please download it as a zip file and send it via email.