Adds Queen Attack test cases from x-common

exercises/queen-attack/example.rb

@@ -3,7 +3,9 @@ class Queens
   def initialize(positions = {})
     @white = positions.fetch(:white) { [0, 3] }
     @black = positions.fetch(:black) { [7, 3] }
-    fail ArgumentError if white == black
+    fail ArgumentError, "Queens cannot be placed on the same spot" if white == black
+    fail ArgumentError, "Positions must be positive numbers" if (white + black).any? { |p| p < 0 }
+    fail ArgumentError, "Positions must have square on board" if (white + black).any? { |p| p > 7 }
   end
 
   def attack?

exercises/queen-attack/queen_attack_test.rb

@@ -34,6 +34,34 @@ def test_cannot_occupy_same_space
     end
   end
 
+  def test_queen_must_have_positive_row
+    skip
+    assert_raises ArgumentError do
+      Queens.new(white: [-2, 2])
+    end
+  end
+
+  def test_queen_must_have_positive_column
+    skip
+    assert_raises ArgumentError do
+      Queens.new(white: [2, -2])
+    end
+  end
+
+  def test_queen_must_have_row_on_board
+    skip
+    assert_raises ArgumentError do
+      Queens.new(white: [8, 4])
+    end
+  end
+
+  def test_queen_must_have_column_on_board
+    skip
+    assert_raises ArgumentError do
+      Queens.new(white: [4, 8])
+    end
+  end
+
   def test_string_representation
     skip
     queens = Queens.new(white: [2, 4], black: [6, 6])
@@ -100,25 +128,25 @@ def test_can_attack_on_same_column
     assert queens.attack?
   end
 
-  def test_can_attack_on_diagonal
+  def test_can_attack_on_first_diagonal
     skip
     queens = Queens.new(white: [1, 1], black: [6, 6])
     assert queens.attack?
   end
 
-  def test_can_attack_on_other_diagonal
+  def test_can_attack_on_second_diagonal
     skip
     queens = Queens.new(white: [0, 6], black: [1, 7])
     assert queens.attack?
   end
 
-  def test_can_attack_on_yet_another_diagonal
+  def test_can_attack_on_third_diagonal
     skip
     queens = Queens.new(white: [4, 1], black: [6, 3])
     assert queens.attack?
   end
 
-  def test_can_attack_on_a_diagonal_slanted_the_other_way
+  def test_can_attack_on_fourth_diagonal
     skip
     queens = Queens.new(white: [6, 1], black: [1, 6])
     assert queens.attack?