Mars Rover kata

Mars Rover kata using UML, TDD, Java

Overview

Program to move rovers around the surface of Mars, which is represented by a number of plateaus, divided into a grid.

Rovers can land on a plateau at specified grid coordinates with a compass heading set and then receive commands to move to the next grid space or spin left or right to face another direction. Multiple rovers can be placed on the same plateau.

Design

UML Class Diagram

Capcom

Takes input and processes commands

Creates and manages plateaus

Creates and manages rovers

Produces status reports

Plateau

Handles coordinate validation requests from rovers

Receives and stores position data for rovers on the plateau to ensure no crashes!

Handles map (if enabled)

Rover

Receives and executes move and spin commands

The interactions between the components can be seen the in Sequence Diagram showing the set-up and processing of a move instruction

Building and Running the application

Once cloned, the application can be built using the following Maven command:

mvn compile package

The unit tests will be executed as part of the build process which produces a jar file in the target directory.

To run the application, from the command line, enter:

java -jar target/mars-rover-1.0-SNAPSHOT.jar

The main method handles console input or the name of file containing instructions be passed as a parameter, e.g.:

java -jar target/mars-rover-1.0-SNAPSHOT.jar instructions.txt

Example instruction files in the testdata folder can also be used, e.g.:

java -jar target/mars-rover-1.0-SNAPSHOT.jar src/test/resources/instructions.txt

Commands to explore Mars

All rovers need a plateau to land on, currently only quadrilateral shaped plateaus are supported.

Create a plateau

Enter the maximum x and y coordinates of the plateau, e.g.

10 10

Creates a 10x10 square with 0,0 coordinate at the bottom left-hand corner
On successful creation a plateau id will be returned. Multiple plateaus can be created.
Maximum size for a Quad Plateau is 9999999,9999999

Create a rover

To create a rover on the current plateau specify its x and y coordinates and heading, e.g.

3 5 N

Creates a rover on the current plateau at coordinates 3,5 with a heading of North. Plateaus can support multiple rovers.

Move and Spin commands

Rover move and spin commends are available to enable exploring:

L - spin left, e.g. if current heading is North, new heading is East
R - spin right
M - move one grid position in the direction of the current heading

A single command can contain multiple move and spin instructions, e.g. LLMMMRMMM

Other commands

SWITCH PLATEAU <plateau-id>	switch to the plateau specified
SWITCH ROVER <rover-id>	switch to the rover specified and plateau rover is on
LIST PLATEAUS	display a list of all plateaus
LIST ROVERS	display a list of all rovers and their location
SHOW MAP	show map for the current plateau (if map feature available)
HIDE MAP	hide map for the current plateau
FINISH	exits the console application
HELP	displays the help text

On exit a report of all rover positions is produced.

Move logic

Rovers cannot land on or move to the space as another Rover on the same plateau.

On receipt of a move command the rover calculates its new coordinates and validates the move with the plateau.

The plateau checks the coordinates are within bounds and the current position of any other rovers. Two rovers cannot share the same coordinates

Screenshot

Future enhancements

Different shaped plateaus

Flying rover

Obstacles on the plateau

Disable rover

Additional Capcoms