clientv3/integration: test on lease close

clientv3/integration/lease_test.go

@@ -102,7 +102,6 @@ func TestLeaseKeepAlive(t *testing.T) {
 	defer clus.Terminate(t)
 
 	lapi := clientv3.NewLease(clus.RandClient())
-	defer lapi.Close()
 
 	resp, err := lapi.Create(context.Background(), 10)
 	if err != nil {
@@ -114,10 +113,21 @@ func TestLeaseKeepAlive(t *testing.T) {
 		t.Errorf("failed to keepalive lease %v", kerr)
 	}
 
-	kresp := <-rc
+	kresp, ok := <-rc
+	if !ok {
+		t.Errorf("chan is closed, want not closed")
+	}
+
 	if kresp.ID != resp.ID {
 		t.Errorf("ID = %x, want %x", kresp.ID, resp.ID)
 	}
+
+	lapi.Close()
+
+	_, ok = <-rc
+	if ok {
+		t.Errorf("chan is not closed, want lease Close() closes chan")
+	}
 }
 
 // TODO: add a client that can connect to all the members of cluster via unix sock.