AccessControl: Team membership migration (#44065)

Co-authored-by: ievaVasiljeva <ieva.vasiljeva@grafana.com>
Co-authored-by: Jguer <joao.guerreiro@grafana.com>

pkg/services/sqlstore/migrations/accesscontrol/util_test.go

@@ -0,0 +1,42 @@
+package accesscontrol
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBatch(t *testing.T) {
+	type testCase struct {
+		desc      string
+		batchSize int
+		count     int
+	}
+
+	testCases := []testCase{
+		{desc: "empty", batchSize: 1, count: 0},
+		{desc: "1 run of 5", batchSize: 5, count: 5},
+		{desc: "10 runs of 5", batchSize: 5, count: 50},
+		{desc: "unmatching end", batchSize: 10, count: 25},
+		{desc: "batch bigger than count", batchSize: 500, count: 25},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			items := make([]int, tc.count)
+			sum := 0
+
+			got := batch(len(items), tc.batchSize, func(start int, end int) error {
+				chunk := items[start:end]
+				for range chunk {
+					sum += 1
+				}
+
+				return nil
+			})
+
+			require.NoError(t, got)
+			require.Equal(t, tc.count, sum)
+		})
+	}
+}