From 7854e11e511350e97b49c1f0f49306b68cc71551 Mon Sep 17 00:00:00 2001
From: Brad Van Vugt <1531419+bvanvugt@users.noreply.github.com>
Date: Sun, 5 Jan 2020 17:08:05 -0800
Subject: [PATCH 1/3] Package name rulesets -> rules.

---
 ruleset.go       | 2 +-
 standard.go      | 2 +-
 standard_test.go | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/ruleset.go b/ruleset.go
index f62b550..e1fa9bb 100644
--- a/ruleset.go
+++ b/ruleset.go
@@ -1,4 +1,4 @@
-package rulesets
+package rules
 
 const (
 	MoveUp    = "up"
diff --git a/standard.go b/standard.go
index 7ff8e50..ed1c1f5 100644
--- a/standard.go
+++ b/standard.go
@@ -1,4 +1,4 @@
-package rulesets
+package rules
 
 import (
 	"errors"
diff --git a/standard_test.go b/standard_test.go
index 93691ec..fe4dca2 100644
--- a/standard_test.go
+++ b/standard_test.go
@@ -1,4 +1,4 @@
-package rulesets
+package rules
 
 import (
 	"errors"

From 9c13dea6c083f463a6a05852c9b3fd9843fef9d2 Mon Sep 17 00:00:00 2001
From: Brad Van Vugt <1531419+bvanvugt@users.noreply.github.com>
Date: Sun, 5 Jan 2020 21:03:54 -0800
Subject: [PATCH 2/3] Add error cases to standard move resolution.

---
 standard.go      | 10 +++++++
 standard_test.go | 71 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/standard.go b/standard.go
index ed1c1f5..f5b147c 100644
--- a/standard.go
+++ b/standard.go
@@ -181,6 +181,13 @@ func (r *StandardRuleset) ResolveMoves(prevState *BoardState, moves []SnakeMove)
 }
 
 func (r *StandardRuleset) moveSnakes(b *BoardState, moves []SnakeMove) error {
+	if len(moves) < len(b.Snakes) {
+		return errors.New("not enough snake moves")
+	}
+	if len(moves) > len(b.Snakes) {
+		return errors.New("too many snake moves")
+	}
+
 	for _, move := range moves {
 		var snake *Snake
 		for i := 0; i < len(b.Snakes); i++ {
@@ -188,6 +195,9 @@ func (r *StandardRuleset) moveSnakes(b *BoardState, moves []SnakeMove) error {
 				snake = &b.Snakes[i]
 			}
 		}
+		if snake == nil {
+			return errors.New("snake not found for move")
+		}
 
 		// Do not move eliminated snakes
 		if snake.EliminatedCause != NotEliminated {
diff --git a/standard_test.go b/standard_test.go
index fe4dca2..be2b016 100644
--- a/standard_test.go
+++ b/standard_test.go
@@ -340,6 +340,77 @@ func TestMoveSnakes(t *testing.T) {
 	}
 }
 
+func TestMoveSnakesWrongID(t *testing.T) {
+	b := &BoardState{
+		Snakes: []Snake{
+			{
+				ID:   "one",
+				Body: []Point{{1, 1}},
+			},
+		},
+	}
+	moves := []SnakeMove{
+		{
+			ID:   "not found",
+			Move: MoveUp,
+		},
+	}
+
+	r := StandardRuleset{}
+	err := r.moveSnakes(b, moves)
+	require.Equal(t, err, errors.New("snake not found"))
+}
+
+func TestMoveSnakesNotEnoughMoves(t *testing.T) {
+	b := &BoardState{
+		Snakes: []Snake{
+			{
+				ID:   "one",
+				Body: []Point{{1, 1}},
+			},
+			{
+				ID:   "two",
+				Body: []Point{{2, 2}},
+			},
+		},
+	}
+	moves := []SnakeMove{
+		{
+			ID:   "two",
+			Move: MoveUp,
+		},
+	}
+
+	r := StandardRuleset{}
+	err := r.moveSnakes(b, moves)
+	require.Equal(t, err, errors.New("not enough snake moves"))
+}
+
+func TestMoveSnakesTooManyMoves(t *testing.T) {
+	b := &BoardState{
+		Snakes: []Snake{
+			{
+				ID:   "one",
+				Body: []Point{{1, 1}},
+			},
+		},
+	}
+	moves := []SnakeMove{
+		{
+			ID:   "one",
+			Move: MoveUp,
+		},
+		{
+			ID:   "two",
+			Move: MoveUp,
+		},
+	}
+
+	r := StandardRuleset{}
+	err := r.moveSnakes(b, moves)
+	require.Equal(t, err, errors.New("too many snake moves"))
+}
+
 func TestIsKnownBoardSize(t *testing.T) {
 	tests := []struct {
 		Width    int32

From b69d768b13d9dfc306635c9a1257bb3b99768e80 Mon Sep 17 00:00:00 2001
From: Brad Van Vugt <1531419+bvanvugt@users.noreply.github.com>
Date: Sun, 5 Jan 2020 21:53:11 -0800
Subject: [PATCH 3/3] correct error message

---
 standard_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/standard_test.go b/standard_test.go
index be2b016..788b1ea 100644
--- a/standard_test.go
+++ b/standard_test.go
@@ -358,7 +358,7 @@ func TestMoveSnakesWrongID(t *testing.T) {
 
 	r := StandardRuleset{}
 	err := r.moveSnakes(b, moves)
-	require.Equal(t, err, errors.New("snake not found"))
+	require.Equal(t, err, errors.New("snake not found for move"))
 }
 
 func TestMoveSnakesNotEnoughMoves(t *testing.T) {