Spacecraft-CLI

A simple CLI to solve the Spacecraft Problem, made with TypeScript

Let's build a rocket together!

The Problem

Say, the Canadian Space Agency is building an unmanned spacecraft that’ll go to the moon.

Here’s some more info about the project.

• The ship’s starting coordinates are (0, 0), which is on Earth.

• The ship’s final destination is (0, 250), which is on the moon.

• The ship will be controlled over a CLI using a standard keyboard as follows:

• The ship starts at (0, 0) at 0 speed, i.e. at complete rest. The ship only moves when a valid key is pressed.

• Pressing W increases the ship’s speed and then moves it forward by speed units.

  • The ship’s maximum speed is 5.

• Pressing S decreases the ship’s speed and then moves it forward by speed units.

  • The ship’s minimum speed is 0.
  • After launch, the ship cannot go below speed 1, i.e. it always moves forward until it reaches the moon.

• Pressing A and D move the ship left and right by one unit respectively.

• The ship also moves forward by speed units.

Problem

Write a CLI program in your preferred language to simulate the above spacecraft. Display output as follows:

• Begin with (0, 0) ready for launch.
• After every movement, display the updated position.
• If the ship goes more than 5 points to the left/right, display wrong trajectory.
• If the ship tries to decrease the speed below 1, display minimum speed.
• If the ship tries to increase the speed over 5, display maximum speed.
• When the ship reaches (0, 250) display on the moon.
• If the ship goes beyond 250 on the y-axis, display contact lost.

Demo

Sample output

(0, 0) # Begin with original position.
(0, 1) # W increases the speed to 1 and moves forward.
(0, 3) # W increases the speed to 2 and moves forward.
(-1, 5) # A moves the ship left and forward.
(0, 7) # D moves the ship right and forward.
(0, 8) # S decreases the speed to 1 and moves forward.
...
(0, 250) on the moon # Ship reaches the moon

Install Globally

npm i -g spacecraft-app-cli

or

You can run directly with npx

npx spacecraft-app-cli

Getting started - Local Development

Requirements

• NodeJS 16.0.0
• Npm 7.10.0

See nvm or asdf

Installation

To get started locally, follow these instructions:

1. Clone to your local computer using git.
2. Make sure you have Node installed; see instructions here.

Usage

# starts 🚀 on coordinates (0,0) - Earth
yarn start

# Use W, A, S, or D  to starting control 🚀 .

Build the CLI bundle

yarn build

Run tests

yarn test

Contributors

Docs

• Contribution Guidelines

License

Copyright (c) 2021 pyymenta

Spacecraft is licensed under the MIT license.