choncou/mars-rover-challenge

Mars Rover Challenge

Usage

• Install Ruby if not already on machine

Solution

• From project root run ruby app/mission_controll.rb

This will kick off Mission Control for controlling the Mars Rover. When prompted with Enter command file name: type in test1.xt or the path to any other file containing commands. The expected result for command files test1.txt and test2.txt can be found on the last line of each file.

The output will show you the current position and bearing of the Rover on the printed line with Final position:

Tests

• Install RSpec by running gem install rspec
• In the project root folder, run rspec to execute tests

Description

The program has been split up into 2 main parts, each encapsulated within its own class. Each part has been tested to validate that their interfaces produce expected results when receiving specific inputs. The different parts, distributed by their responsibility of duties, are:

1. Mission Control

The MissionControl class in app/mission_control.rb is responsible for receiving user input which specifies the file containing the Rover's configuration and commands instruction. Mission Control is also responsible for displaying any output to the user(console).

Design:

• The logic of extracting the config & command properties from the input file has been extracted into it's own function. If the format of how these files are structured where to change, the public user interface #start_rover_mission would not be tampered. Only #props_from_file would need to be updated to correct read the data from the file and return the properties in the expected agreed format.

Testing: spec/mission_control_spec.rb

• The correctness of MissionControl's functionality has been insured by testing that #start_rover_mission with a specified input, outputs the expected and correct output to console

2. Rover

The Rover class in app/rover.rb is responsible for configuring the properties of the Rover as given by Mission Control, and allow execution of a list of commands.

Design:

• The Rover has be setup with a public interface that will allow the user to view the zone, current_position, and a function to execute a list of commands. Rover is not responsible for the way in which input is received, and output displayed to the user.
• There are more granular functionalities related to the execution of individual events, which should only be accessed internally for use by the Rover itself. This also includes the DIRECTION_MAPPING to determine bearing. The user of the Rover should not be concerned about specific and implementation details.

Testing: spec/rover_spec.rb

• The correctness of the Rover has been ensured by testing that when initialized with specific values, the properties are set and return the expected result to the user when they access one of the public methods.
• The main functionality of the Rover is to execute the given commands, and this has been tested by ensuring that a predefined input always return the same expected result containing the final location. Note that an empty command list should not move the Rover at all.
• There are also a few specs which have been commented out:
  • These would serve to test that the Rover behaves as expected when an edge case is encountered, such as invalid input. This should be implemented if the expected behaviour is included in the specifications. This would then require updating the rover.rb to ensure that it behaves as specified.