integration: add TestV3WatchWithPrevKV

integration/v3_watch_test.go

@@ -1079,3 +1079,72 @@ func TestV3WatchWithFilter(t *testing.T) {
 		t.Fatal("failed to receive delete event")
 	}
 }
+
+func TestV3WatchWithPrevKV(t *testing.T) {
+	clus := NewClusterV3(t, &ClusterConfig{Size: 1})
+	defer clus.Terminate(t)
+
+	tests := []struct {
+		key  string
+		end  string
+		vals []string
+	}{{
+		key:  "foo",
+		end:  "fop",
+		vals: []string{"bar1", "bar2"},
+	}, {
+		key:  "/abc",
+		end:  "/abd",
+		vals: []string{"first", "second"},
+	}}
+	for i, tt := range tests {
+		kvc := toGRPC(clus.RandClient()).KV
+		if _, err := kvc.Put(context.TODO(), &pb.PutRequest{Key: []byte(tt.key), Value: []byte(tt.vals[0])}); err != nil {
+			t.Fatal(err)
+		}
+
+		ws, werr := toGRPC(clus.RandClient()).Watch.Watch(context.TODO())
+		if werr != nil {
+			t.Fatal(werr)
+		}
+
+		req := &pb.WatchRequest{RequestUnion: &pb.WatchRequest_CreateRequest{
+			CreateRequest: &pb.WatchCreateRequest{
+				Key:      []byte(tt.key),
+				RangeEnd: []byte(tt.end),
+				PrevKv:   true,
+			}}}
+		if err := ws.Send(req); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := ws.Recv(); err != nil {
+			t.Fatal(err)
+		}
+
+		if _, err := kvc.Put(context.TODO(), &pb.PutRequest{Key: []byte(tt.key), Value: []byte(tt.vals[1])}); err != nil {
+			t.Fatal(err)
+		}
+
+		recv := make(chan *pb.WatchResponse)
+		go func() {
+			// check received PUT
+			resp, rerr := ws.Recv()
+			if rerr != nil {
+				t.Fatal(rerr)
+			}
+			recv <- resp
+		}()
+
+		select {
+		case resp := <-recv:
+			if tt.vals[1] != string(resp.Events[0].Kv.Value) {
+				t.Errorf("#%d: unequal value: want=%s, get=%s", i, tt.vals[1], resp.Events[0].Kv.Value)
+			}
+			if tt.vals[0] != string(resp.Events[0].PrevKv.Value) {
+				t.Errorf("#%d: unequal value: want=%s, get=%s", i, tt.vals[0], resp.Events[0].PrevKv.Value)
+			}
+		case <-time.After(30 * time.Second):
+			t.Error("timeout waiting for watch response")
+		}
+	}
+}