Ensure that a rover can only traverse within the provided terrain bou…

…ndary limits

The position is composed of the Terrain instead of the Rover. Appropriate changes are made accordingly.

Additional misc changes added include:

- Fix test description with regard to invalid Step
- Add custom rubocop rules on cops to ignore
- Fix rubocop related offenses

.rubocop.yml

@@ -0,0 +1,8 @@
+Metrics/BlockLength:
+  Enabled: false
+Style/Documentation:
+  Enabled: false
+Metrics/MethodLength:
+  Max: 25 # Default: 10
+Naming/AccessorMethodName:
+  Enabled: false

bin/deploy_mars_rover.rb

@@ -6,16 +6,16 @@
 require_relative '../lib/rectangular_plateau'
 require 'pry' # Handy for debugging purposes
 
-terrain = RectangularPlateau.new(5, 5)
+terrain = RectangularPlateau.new(0, 0, 5, 5)
 
 path1 = Path.new('LMLMLMLMM')
 path2 = Path.new('MMRMMRMRRM')
 
-rover_1 = Rover.new(RoverPosition.new(1, 2, 'N'), terrain)
-rover_2 = Rover.new(RoverPosition.new(3, 3, 'E'), terrain)
+rover1 = Rover.new(RoverPosition.new(1, 2, 'N', terrain))
+rover2 = Rover.new(RoverPosition.new(3, 3, 'E', terrain))
 
-rover_1.traverse(path1)
-puts rover_1.current_position.location
+rover1.traverse(path1)
+puts rover1.current_position.location
 
-rover_2.traverse(path2)
-puts rover_2.current_position.location
+rover2.traverse(path2)
+puts rover2.current_position.location

lib/rectangular_plateau.rb

@@ -1,8 +1,34 @@
 # frozen_string_literal: true
 
 class RectangularPlateau
-  def initialize(length, breadth)
-    @length = length
-    @breadth = breadth
+  def initialize(lower_x_coordinate, lower_y_coordinate, upper_x_coordinate, upper_y_coordinate)
+    @lower_x_coordinate = lower_x_coordinate
+    @lower_y_coordinate = lower_y_coordinate
+    @upper_x_coordinate = upper_x_coordinate
+    @upper_y_coordinate = upper_y_coordinate
   end
+
+  def upward_vertical_movement_permissible?(y_position)
+    y_position >= lower_y_coordinate &&
+      y_position < upper_y_coordinate
+  end
+
+  def downward_vertical_movement_permissible?(y_position)
+    y_position > lower_y_coordinate &&
+      y_position <= upper_y_coordinate
+  end
+
+  def forward_horizontal_movement_permissible?(x_position)
+    x_position >= lower_x_coordinate &&
+      x_position < upper_x_coordinate
+  end
+
+  def backward_horizontal_movement_permissible?(x_position)
+    x_position > lower_x_coordinate &&
+      x_position <= upper_x_coordinate
+  end
+
+  private
+
+  attr_reader :lower_x_coordinate, :lower_y_coordinate, :upper_x_coordinate, :upper_y_coordinate
 end

lib/rover.rb

@@ -6,9 +6,8 @@
 require_relative 'west'
 
 class Rover
-  def initialize(current_position, terrain)
+  def initialize(current_position)
     @current_position = current_position
-    @terrain = terrain
   end
 
   attr_reader :current_position

lib/rover_position.rb

@@ -1,27 +1,46 @@
 # frozen_string_literal: true
 
+class OutsideBoundaryLimitsError < StandardError; end
+
 class RoverPosition
-  def initialize(x_coordinate, y_coordinate, orientation)
+  def initialize(x_coordinate, y_coordinate, orientation, terrain)
     @x_coordinate = x_coordinate
     @y_coordinate = y_coordinate
     @orientation = orientation
+    @terrain = terrain
   end
 
-  attr_reader :y_coordinate, :x_coordinate, :orientation
+  attr_reader :y_coordinate, :x_coordinate, :orientation, :terrain
 
   def move_vertically_upward
+    unless terrain.upward_vertical_movement_permissible?(y_coordinate)
+      raise OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits'
+    end
+
     self.y_coordinate += 1
   end
 
   def move_vertically_downward
+    unless terrain.downward_vertical_movement_permissible?(y_coordinate)
+      raise OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits'
+    end
+
     self.y_coordinate -= 1
   end
 
   def move_horizontally_forward
+    unless terrain.forward_horizontal_movement_permissible?(x_coordinate)
+      raise OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits'
+    end
+
     self.x_coordinate += 1
   end
 
   def move_horizontally_backward
+    unless terrain.backward_horizontal_movement_permissible?(x_coordinate)
+      raise OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits'
+    end
+
     self.x_coordinate -= 1
   end
 

spec/lib/east_spec.rb

@@ -24,7 +24,7 @@
   describe '#move' do
     context 'given an entity points in the East direction' do
       it 'moves a step forward horizontally along that path(i.e., along the x-axis)' do
-        current_position = RoverPosition.new(1, 3, 'E')
+        current_position = RoverPosition.new(1, 3, 'E', RectangularPlateau.new(0, 0, 5, 5))
 
         east.move(current_position)
 

spec/lib/north_spec.rb

@@ -24,7 +24,7 @@
   describe '#move' do
     context 'given an entity points in the North direction' do
       it 'moves a step upward vertically along that path(i.e., along the y-axis)' do
-        current_position = RoverPosition.new(1, 3, 'N')
+        current_position = RoverPosition.new(1, 3, 'N', RectangularPlateau.new(0, 0, 5, 5))
 
         north.move(current_position)
 

spec/lib/rectangular_plateau_spec.rb

@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+describe RectangularPlateau do
+  let(:terrain) { RectangularPlateau.new(0, 0, 5, 5) }
+
+  describe '#upward_vertical_movement_permissible?' do
+    context 'when an entity wants to move vertically upward along the Y-axis' do
+      context 'movement is within terrain boundary limits' do
+        it 'returns true' do
+          current_position = RoverPosition.new(1, 3, 'N', terrain)
+
+          expect(terrain.upward_vertical_movement_permissible?(current_position.y_coordinate)).to be true
+        end
+      end
+
+      context 'movement is outside terrain boundary limits' do
+        it 'returns false' do
+          current_position = RoverPosition.new(1, 5, 'N', terrain)
+
+          expect(terrain.upward_vertical_movement_permissible?(current_position.y_coordinate)).to be false
+        end
+      end
+    end
+  end
+
+  describe '#downward_vertical_movement_permissible?' do
+    context 'when an entity wants to move vertically downward along the Y-axis' do
+      context 'movement is within terrain boundary limits' do
+        it 'returns true' do
+          current_position = RoverPosition.new(1, 3, 'S', terrain)
+
+          expect(terrain.downward_vertical_movement_permissible?(current_position.y_coordinate)).to be true
+        end
+      end
+
+      context 'movement is outside terrain boundary limits' do
+        it 'returns false' do
+          current_position = RoverPosition.new(1, 0, 'S', terrain)
+
+          expect(terrain.downward_vertical_movement_permissible?(current_position.y_coordinate)).to be false
+        end
+      end
+    end
+  end
+
+  describe '#forward_horizontal_movement_permissible?' do
+    context 'when an entity wants to move horizontally forward along the X-axis' do
+      context 'movement is within terrain boundary limits' do
+        it 'returns true' do
+          current_position = RoverPosition.new(1, 3, 'E', terrain)
+
+          expect(terrain.forward_horizontal_movement_permissible?(current_position.x_coordinate)).to be true
+        end
+      end
+
+      context 'movement is outside terrain boundary limits' do
+        it 'returns false' do
+          current_position = RoverPosition.new(5, 3, 'E', terrain)
+
+          expect(terrain.forward_horizontal_movement_permissible?(current_position.x_coordinate)).to be false
+        end
+      end
+    end
+  end
+
+  describe '#backward_horizontal_movement_permissible?' do
+    context 'when an entity wants to move horizontally backward along the X-axis' do
+      context 'movement is within terrain boundary limits' do
+        it 'returns true' do
+          current_position = RoverPosition.new(1, 3, 'W', terrain)
+
+          expect(terrain.backward_horizontal_movement_permissible?(current_position.x_coordinate)).to be true
+        end
+      end
+
+      context 'movement is outside terrain boundary limits' do
+        it 'returns false' do
+          current_position = RoverPosition.new(0, 5, 'W', terrain)
+
+          expect(terrain.backward_horizontal_movement_permissible?(current_position.x_coordinate)).to be false
+        end
+      end
+    end
+  end
+end

spec/lib/rover_position_spec.rb

@@ -1,61 +1,111 @@
 # frozen_string_literal: true
 
 describe RoverPosition do
+  let(:terrain) { RectangularPlateau.new(0, 0, 5, 5) }
+
   describe '#move_vertically_upward' do
-    it 'allows one to go further up the Y axis(for e.g., in imagine a 2 Dimensional Grid system) by one unit' do
-      current_position = RoverPosition.new(1, 3, 'N')
+    context 'movement attempted within terrain boundary limits' do
+      it 'allows one to go further up the Y axis(imagine a 2D Grid system) by one unit' do
+        current_position = RoverPosition.new(1, 3, 'N', terrain)
+
+        current_position.move_vertically_upward
+
+        expect(current_position.x_coordinate).to eq 1
+        expect(current_position.y_coordinate).to eq 4
+      end
+    end
 
-      current_position.move_vertically_upward
+    context 'movement attempted outside terrain boundary limits' do
+      it 'returns an outside boundary limits error with related message' do
+        current_position = RoverPosition.new(1, 5, 'N', terrain)
 
-      expect(current_position.x_coordinate).to eq 1
-      expect(current_position.y_coordinate).to eq 4
+        expect do
+          current_position.move_vertically_upward
+        end.to raise_error(OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits')
+      end
     end
   end
 
   describe '#move_vertically_downward' do
-    it 'allows one to go further down the Y axis(for e.g., in imagine a 2 Dimensional Grid system) by one unit' do
-      current_position = RoverPosition.new(1, 3, 'S')
+    context 'movement attempted within terrain boundary limits' do
+      it 'allows one to go further down the Y axis(imagine a 2D Grid system) by one unit' do
+        current_position = RoverPosition.new(1, 3, 'S', terrain)
+
+        current_position.move_vertically_downward
+
+        expect(current_position.x_coordinate).to eq 1
+        expect(current_position.y_coordinate).to eq 2
+      end
+    end
 
-      current_position.move_vertically_downward
+    context 'movement attempted outside terrain boundary limits' do
+      it 'returns an outside boundary limits error with related message' do
+        current_position = RoverPosition.new(1, 0, 'S', terrain)
 
-      expect(current_position.x_coordinate).to eq 1
-      expect(current_position.y_coordinate).to eq 2
+        expect do
+          current_position.move_vertically_downward
+        end.to raise_error(OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits')
+      end
     end
   end
 
   describe '#move_horizontally_forward' do
-    it 'allows one to go a step further horizontally on the  X axis(for e.g., in imagine a 2 Dimensional Grid system) by one unit' do
-      current_position = RoverPosition.new(1, 3, 'E')
+    context 'movement attempted within terrain boundary limits' do
+      it 'allows one to go a step further horizontally on the  X axis(imagine a 2D Grid system) by one unit' do
+        current_position = RoverPosition.new(1, 3, 'E', terrain)
 
-      current_position.move_horizontally_forward
+        current_position.move_horizontally_forward
 
-      expect(current_position.x_coordinate).to eq 2
-      expect(current_position.y_coordinate).to eq 3
+        expect(current_position.x_coordinate).to eq 2
+        expect(current_position.y_coordinate).to eq 3
+      end
+    end
+
+    context 'movement attempted outside terrain boundary limits' do
+      it 'returns an outside boundary limits error with related message' do
+        current_position = RoverPosition.new(5, 3, 'E', terrain)
+
+        expect do
+          current_position.move_horizontally_forward
+        end.to raise_error(OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits')
+      end
     end
   end
 
   describe '#move_horizontally_backward' do
-    it 'allows one to go a step backward horizontally on the X axis(for e.g., in imagine a 2 Dimensional Grid system) by one unit' do
-      current_position = RoverPosition.new(1, 3, 'W')
+    context 'movement attempted within terrain boundary limits' do
+      it 'allows one to go a step backward horizontally on the X axis(imagine a 2D Grid system) by one unit' do
+        current_position = RoverPosition.new(1, 3, 'W', terrain)
+
+        current_position.move_horizontally_backward
+
+        expect(current_position.x_coordinate).to eq 0
+        expect(current_position.y_coordinate).to eq 3
+      end
+    end
 
-      current_position.move_horizontally_backward
+    context 'movement attempted outside terrain boundary limits' do
+      it 'returns an outside boundary limits error with related message' do
+        current_position = RoverPosition.new(0, 5, 'W', terrain)
 
-      expect(current_position.x_coordinate).to eq 0
-      expect(current_position.y_coordinate).to eq 3
+        expect do
+          current_position.move_horizontally_backward
+        end.to raise_error(OutsideBoundaryLimitsError, 'Movement not permissible outside terrain boundary limits')
+      end
     end
   end
 
   describe '#get_orientation' do
     it 'returns the current compass based position of a given entity' do
-      current_position = RoverPosition.new(1, 3, 'W')
+      current_position = RoverPosition.new(1, 3, 'W', terrain)
 
       expect(current_position.get_orientation).to eq('W')
     end
   end
 
   describe '#set_orientation' do
     it 'sets a compass based position for a given entity' do
-      current_position = RoverPosition.new(1, 3, 'W')
+      current_position = RoverPosition.new(1, 3, 'W', terrain)
 
       current_position.set_orientation('N')
 
@@ -65,7 +115,7 @@
 
   describe '#location' do
     it 'returns the current location of a given entity' do
-      current_position = RoverPosition.new(1, 3, 'W')
+      current_position = RoverPosition.new(1, 3, 'W', terrain)
 
       expect(current_position.location).to eq('1 3 W')
     end