Add RulesetError test case.

Remove old comments.

ruleset.go

@@ -1,10 +1,36 @@
 package rules
 
+type RulesetError string
+
+func (err RulesetError) Error() string { return string(err) }
+
 const (
 	MoveUp    = "up"
 	MoveDown  = "down"
 	MoveRight = "right"
 	MoveLeft  = "left"
+
+	BoardSizeSmall  = 7
+	BoardSizeMedium = 11
+	BoardSizeLarge  = 19
+
+	SnakeMaxHealth = 100
+	SnakeStartSize = 3
+
+	// bvanvugt - TODO: Just return formatted strings instead of codes?
+	NotEliminated                   = ""
+	EliminatedByCollision           = "snake-collision"
+	EliminatedBySelfCollision       = "snake-self-collision"
+	EliminatedByOutOfHealth         = "out-of-health"
+	EliminatedByHeadToHeadCollision = "head-collision"
+	EliminatedByOutOfBounds         = "wall-collision"
+
+	// TODO - Error consts
+	ErrorTooManySnakes   = RulesetError("too many snakes for fixed start positions")
+	ErrorNoRoomForSnake  = RulesetError("not enough space to place snake")
+	ErrorNoRoomForFood   = RulesetError("not enough space to place food")
+	ErrorNoMoveFound     = RulesetError("move not provided for snake")
+	ErrorZeroLengthSnake = RulesetError("snake is length zero")
 )
 
 type Point struct {
@@ -37,7 +63,3 @@ type Ruleset interface {
 	CreateNextBoardState(prevState *BoardState, moves []SnakeMove) (*BoardState, error)
 	IsGameOver(state *BoardState) (bool, error)
 }
-
-type RulesetError string
-
-func (err RulesetError) Error() string { return string(err) }