[#1445] metabase/test: Add test for GetLocks method

Since it'll be working with locks of the new format, i. e. locks with
expiration epoch, it's better to have a test for this method to ensure
it can handle locks of both old and new formats.

Signed-off-by: Aleksey Savchuk <a.savchuk@yadro.com>

pkg/local_object_storage/metabase/lock_test.go

@@ -288,3 +288,41 @@ func putAndLockObj(t *testing.T, db *meta.DB, numOfLockedObjs int) ([]*objectSDK
 
 	return lockedObjs, lockObj
 }
+
+func TestGetLocks(t *testing.T) {
+	t.Parallel()
+
+	db := newDB(t)
+	defer func() { require.NoError(t, db.Close(context.Background())) }()
+
+	object := oidtest.Address()
+
+	t.Run("no locks for object", func(t *testing.T) {
+		gotLocks, err := db.GetLocks(context.Background(), object)
+		require.NoError(t, err)
+		require.Empty(t, gotLocks)
+	})
+
+	locks := []meta.Lock{
+		{oidtest.ID(), 1},
+		{oidtest.ID(), 2},
+	}
+
+	for _, lock := range locks {
+		require.NoError(t,
+			db.Lock(context.Background(), object.Container(), lock.ID, []oid.ID{object.Object()}, lock.ExpEpoch),
+		)
+
+		// try to lock with the same lock object to ensure
+		// that all locks are unique and set only once.
+		require.NoError(t,
+			db.Lock(context.Background(), object.Container(), lock.ID, []oid.ID{object.Object()}, lock.ExpEpoch+100),
+		)
+	}
+
+	t.Run("object is locked", func(t *testing.T) {
+		gotLocks, err := db.GetLocks(context.Background(), object)
+		require.NoError(t, err)
+		require.ElementsMatch(t, locks, gotLocks)
+	})
+}