Initial commit

implemented the game of life variation with hexagonal grid

grid/hex_test.go

@@ -0,0 +1,83 @@
+package grid
+
+import (
+	"testing"
+)
+
+func TestHex_NeighborAt(t *testing.T) {
+	testCases := []struct {
+		name      string
+		hex       Hex
+		direction int
+		want      Hex
+	}{
+		{
+			name:      "zero hex zero direction",
+			hex:       Hex{},
+			direction: 0,
+			want:      NewHex(1, 0),
+		},
+		{
+			name:      "zero hex direction 1",
+			hex:       Hex{},
+			direction: 1,
+			want:      NewHex(0, 1),
+		},
+		{
+			name:      "zero hex direction 2",
+			hex:       Hex{},
+			direction: 2,
+			want:      NewHex(-1, 1),
+		},
+		{
+			name:      "zero hex direction 3",
+			hex:       Hex{},
+			direction: 3,
+			want:      NewHex(-1, 0),
+		},
+		{
+			name:      "zero hex direction 4",
+			hex:       Hex{},
+			direction: 4,
+			want:      NewHex(0, -1),
+		},
+		{
+			name:      "zero hex zero direction 5",
+			hex:       Hex{},
+			direction: 5,
+			want:      NewHex(1, -1),
+		},
+		{
+			name:      "zero hex zero direction overflow",
+			hex:       Hex{},
+			direction: 6,
+			want:      NewHex(1, 0),
+		},
+		{
+			name:      "zero hex zero direction overflow twice",
+			hex:       Hex{},
+			direction: 12,
+			want:      NewHex(1, 0),
+		},
+		{
+			name:      "zero hex zero direction underflow",
+			hex:       Hex{},
+			direction: -1,
+			want:      NewHex(1, -1),
+		},
+		{
+			name:      "zero hex zero direction underflow twice",
+			hex:       Hex{},
+			direction: -7,
+			want:      NewHex(1, -1),
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := tc.hex.NeighborAt(tc.direction)
+			if tc.want != got {
+				t.Fatalf("want %v but got %v", tc.want, got)
+			}
+		})
+	}
+}