From e01a1bf50518b152810ac38068619f50856bf7ef Mon Sep 17 00:00:00 2001
From: Brad Van Vugt <1531419+bvanvugt@users.noreply.github.com>
Date: Tue, 8 Dec 2020 13:20:13 -0800
Subject: [PATCH] "Feast" -> "Maze". Fix backfill bug. (#26)

---
 feast.go => maze.go           |  8 ++--
 feast_test.go => maze_test.go | 88 +++++++++++++++++++++++++++++++----
 standard.go                   |  3 ++
 3 files changed, 86 insertions(+), 13 deletions(-)
 rename feast.go => maze.go (66%)
 rename feast_test.go => maze_test.go (54%)

diff --git a/feast.go b/maze.go
similarity index 66%
rename from feast.go
rename to maze.go
index 0f916f3..33e0363 100644
--- a/feast.go
+++ b/maze.go
@@ -2,11 +2,11 @@ package rules
 
 import ()
 
-type FeastRuleset struct {
+type MazeRuleset struct {
 	StandardRuleset
 }
 
-func (r *FeastRuleset) CreateInitialBoardState(width int32, height int32, snakeIDs []string) (*BoardState, error) {
+func (r *MazeRuleset) CreateInitialBoardState(width int32, height int32, snakeIDs []string) (*BoardState, error) {
 	initialBoardState, err := r.StandardRuleset.CreateInitialBoardState(width, height, snakeIDs)
 	if err != nil {
 		return nil, err
@@ -20,7 +20,7 @@ func (r *FeastRuleset) CreateInitialBoardState(width int32, height int32, snakeI
 	return initialBoardState, nil
 }
 
-func (r *FeastRuleset) CreateNextBoardState(prevState *BoardState, moves []SnakeMove) (*BoardState, error) {
+func (r *MazeRuleset) CreateNextBoardState(prevState *BoardState, moves []SnakeMove) (*BoardState, error) {
 	nextState, err := r.StandardRuleset.CreateNextBoardState(prevState, moves)
 	if err != nil {
 		return nil, err
@@ -34,7 +34,7 @@ func (r *FeastRuleset) CreateNextBoardState(prevState *BoardState, moves []Snake
 	return nextState, nil
 }
 
-func (r *FeastRuleset) fillBoardWithFood(b *BoardState) error {
+func (r *MazeRuleset) fillBoardWithFood(b *BoardState) error {
 	unoccupiedPoints := r.getUnoccupiedPoints(b, true)
 	b.Food = append(b.Food, unoccupiedPoints...)
 	return nil
diff --git a/feast_test.go b/maze_test.go
similarity index 54%
rename from feast_test.go
rename to maze_test.go
index c3eb74f..8304bf0 100644
--- a/feast_test.go
+++ b/maze_test.go
@@ -6,11 +6,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestFeastRulesetInterface(t *testing.T) {
-	var _ Ruleset = (*FeastRuleset)(nil)
+func TestMazeRulesetInterface(t *testing.T) {
+	var _ Ruleset = (*MazeRuleset)(nil)
 }
 
-func TestFeastCreateInitialBoardState(t *testing.T) {
+func TestMazeCreateInitialBoardState(t *testing.T) {
 	tests := []struct {
 		Height          int32
 		Width           int32
@@ -27,7 +27,7 @@ func TestFeastCreateInitialBoardState(t *testing.T) {
 		{11, 11, []string{"one", "two", "three", "four", "five"}, 116, nil},
 	}
 
-	r := FeastRuleset{}
+	r := MazeRuleset{}
 	for testNum, test := range tests {
 		state, err := r.CreateInitialBoardState(test.Width, test.Height, test.IDs)
 		require.Equal(t, test.Err, err)
@@ -46,11 +46,10 @@ func TestFeastCreateInitialBoardState(t *testing.T) {
 	}
 }
 
-func TestFeastCreateNextBoardState(t *testing.T) {
+func TestMazeCreateNextBoardState(t *testing.T) {
 	tests := []struct {
 		prevState     *BoardState
 		moves         []SnakeMove
-		expectedError error
 		expectedState *BoardState
 	}{
 		{
@@ -75,7 +74,6 @@ func TestFeastCreateNextBoardState(t *testing.T) {
 				{ID: "one", Move: MoveDown},
 				{ID: "two", Move: MoveUp},
 			},
-			nil,
 			&BoardState{
 				Width:  3,
 				Height: 3,
@@ -94,12 +92,84 @@ func TestFeastCreateNextBoardState(t *testing.T) {
 				Food: []Point{{0, 2}, {1, 1}, {2, 0}},
 			},
 		},
+		// Ensure food is spawning in front of snakes
+		{
+			&BoardState{
+				Width:  3,
+				Height: 3,
+				Snakes: []Snake{
+					{
+						ID:     "one",
+						Body:   []Point{{1, 0}, {1, 0}, {1, 0}},
+						Health: 75,
+					},
+				},
+				Food: []Point{},
+			},
+			[]SnakeMove{
+				{ID: "one", Move: MoveDown},
+			},
+			&BoardState{
+				Width:  3,
+				Height: 3,
+				Snakes: []Snake{
+					{
+						ID:     "one",
+						Body:   []Point{{1, 1}, {1, 0}, {1, 0}},
+						Health: 74,
+					},
+				},
+				Food: []Point{{0, 0}, {0, 1}, {0, 2}, {1, 2}, {2, 0}, {2, 1}, {2, 2}},
+			},
+		},
+		// Ensure eliminated snakes are immediately replace with food
+		{
+			&BoardState{
+				Width:  3,
+				Height: 3,
+				Snakes: []Snake{
+					{
+						ID:     "one",
+						Body:   []Point{{1, 0}, {2, 0}, {2, 0}},
+						Health: 100,
+					},
+					{
+						ID:     "two",
+						Body:   []Point{{2, 2}, {1, 2}, {0, 2}},
+						Health: 100,
+					},
+				},
+				Food: []Point{},
+			},
+			[]SnakeMove{
+				{ID: "one", Move: MoveLeft},
+				{ID: "two", Move: MoveDown},
+			},
+			&BoardState{
+				Width:  3,
+				Height: 3,
+				Snakes: []Snake{
+					{
+						ID:     "one",
+						Body:   []Point{{0, 0}, {1, 0}, {2, 0}},
+						Health: 99,
+					},
+					{
+						ID:              "two",
+						Body:            []Point{{2, 3}, {2, 2}, {1, 2}},
+						Health:          99,
+						EliminatedCause: EliminatedByOutOfBounds,
+					},
+				},
+				Food: []Point{{0, 1}, {0, 2}, {1, 1}, {1, 2}, {2, 1}, {2, 2}},
+			},
+		},
 	}
 
-	r := FeastRuleset{}
+	r := MazeRuleset{}
 	for _, test := range tests {
 		nextState, err := r.CreateNextBoardState(test.prevState, test.moves)
-		require.Equal(t, test.expectedError, err)
+		require.NoError(t, err)
 		require.Equal(t, test.expectedState, nextState)
 	}
 }
diff --git a/standard.go b/standard.go
index 4fd444e..2d78af7 100644
--- a/standard.go
+++ b/standard.go
@@ -548,6 +548,9 @@ func (r *StandardRuleset) getUnoccupiedPoints(b *BoardState, includePossibleMove
 		pointIsOccupied[p.X][p.Y] = true
 	}
 	for _, snake := range b.Snakes {
+		if snake.EliminatedCause != NotEliminated {
+			continue
+		}
 		for i, p := range snake.Body {
 			if _, xExists := pointIsOccupied[p.X]; !xExists {
 				pointIsOccupied[p.X] = map[int32]bool{}