bkleinen / mars-rover-kata

Mars Rover Kata Solution

see e.g. https://kata-log.rocks/mars-rover-kata

This is my solution of the mars rover kata in python.

I developed it using TDD.

I've implemented both a square World and a Planet with Poles. Drawing this made it occur to me that this is missing an abstraction for Direction or rather Orientation handling everything that has to do with 'N','E','S','W':

classDiagram
    World <|-- Planet
    class World{
        int width
        int height
        add_obstacle()
        RoverState next(rover_state, command)
    }
    class Planet{
      RoverState next_on_pole(rover_state, command)
    }
    class Rover{
        RoverState rover_state
        World world
        execute(input)
        RoverState position()
    }
    Rover ..> Command
    Rover *-- RoverState
    RoverState *-- Orientation
    RoverState *-- Position
    Rover --> World
    
    class RoverState{
      Position pos
      Orientation orientation
      
    }
    class Position{
      int x
      int y
    }


    class Orientation{
      <<Enumeration>>
      N, E, S, W
    }
     Orientation

    Command <|-- MoveCommand
    Command <|-- TurnCommand
    Command ..> RoverState
    MoveCommand ..> World
    class Command{
      execute(rover_state, world)
    }
    
    
     

https://mermaid.js.org/syntax/classDiagram.html

Planet Implementation

-testcases = [

• T(Planet,12,RS(1,1,"N"), "f", RS(1,2,"N"), ),
• T(World,12,RS(1,11,"N"), "f", RS(1,0,"N"), xfail=False),

Crossing the poles

n: number of longitudes

The longitudes are represented by the x values. The x value is determined to describe the direction on the poles; it serves as a history for where the rover came from. Without a turn, it moves along the same line - that is the opposite

new_tests = [pytest.param(*t,marks=pytest.mark.xfail) for t in new_tests]

N W E S

0 1 2 3

von oben (N): 2 3 1 0 r: E 1 turns , x + 1 l: W 3 turns , x - 1

von unten (S): 0 3 1 2

l: E 1 turns , x + 1 r: W 3 turns , x - 1