Mars Rovers Test

Problem

A squad of robotic rovers are to be landed by NASA on a plateau on Mars. This plateau, which is curiously rectangular, must be navigated by the rovers so that their on-board cameras can get a complete view of the surrounding terrain to send back to Earth.

A rover's position and location is represented by a combination of x and y co-ordinates and a letter representing one of the four cardinal compass points. The plateau is divided up into a grid to simplify navigation. An example position might be 0, 0, N, which means the rover is in the bottom left corner and facing North.

In order to control a rover, NASA sends a simple string of letters. The possible letters are 'L', 'R' and 'M'. 'L' and 'R' makes the rover spin 90 degrees left or right respectively, without moving from its current spot. 'M' means move forward one grid point, and maintain the same heading.

Assume that the square directly North from (x, y) is (x, y+1).

Input

The first line of input is the upper-right coordinates of the plateau, the lower-left coordinates are assumed to be 0,0.

The rest of the input is information pertaining to the rovers that have been deployed. Each rover has two lines of input. The first line gives the rover's position, and the second line is a series of instructions telling the rover how to explore the plateau.

The position is made up of two integers and a letter separated by spaces, corresponding to the x and y co-ordinates and the rover's orientation.

Each rover will be finished sequentially, which means that the second rover won't start to move until the first one has finished moving.

Output

The output for each rover should be its final co-ordinates and heading.

Test Input

5 5
1 2 N
LMLMLMLMM
3 3 E
MMRMMRMRRM

Expected Output

1 3 N
5 1 E

Resolution

I've choose Node.js with Typescript to solve this problem because it's a language I like to work with.

Project techs/libs

• Typescript - To help with code completion and make it easier for other devs to understand;
• Node.js - Because it's a popular "language";
• Jest - The most popular Javascript testing framework;
• Eslint - To standardize and enforce the code style (Airbnb style);

Project structure

• __tests__ - Where all unit tests are stored;
• helpers - Where I've placed helper functions to keep classes more clean as possible;
• models - Where I keep all the business logic;
• validators - Functions that will be used as ES6 Decorators to validate attributes and keep classes more clean as possible;

How to execute

Requirements

• Node.js v12+
• Yarn or NPM

Install dependencies

yarn install
# or
npm install

Testing

yarn test
# or
npm run test

# you can use test:coverage instead of test to show test coverage (e.g: yarn test:coverage)

Execute

yarn start
# or
npm start