[release-19.0] vtctldclient: Apply (Shard | Keyspace| Table) Routing Rules commands don't work (#16096)

go/cmd/vtctldclient/command/routing_rules.go

@@ -82,7 +82,7 @@ func commandApplyRoutingRules(cmd *cobra.Command, args []string) error {
 	}
 
 	rr := &vschemapb.RoutingRules{}
-	if err := json2.Unmarshal(rulesBytes, &rr); err != nil {
+	if err := json2.UnmarshalPB(rulesBytes, rr); err != nil {
 		return err
 	}
 

go/cmd/vtctldclient/command/shard_routing_rules.go

@@ -87,7 +87,7 @@ func commandApplyShardRoutingRules(cmd *cobra.Command, args []string) error {
 	}
 
 	srr := &vschemapb.ShardRoutingRules{}
-	if err := json2.Unmarshal(rulesBytes, &srr); err != nil {
+	if err := json2.UnmarshalPB(rulesBytes, srr); err != nil {
 		return err
 	}
 	// Round-trip so when we display the result it's readable.

go/json2/unmarshal.go

@@ -33,8 +33,7 @@ var carriageReturn = []byte("\n")
 // efficient and should not be used for high QPS operations.
 func Unmarshal(data []byte, v any) error {
 	if pb, ok := v.(proto.Message); ok {
-		opts := protojson.UnmarshalOptions{DiscardUnknown: true}
-		return annotate(data, opts.Unmarshal(data, pb))
+		return UnmarshalPB(data, pb)
 	}
 	return annotate(data, json.Unmarshal(data, v))
 }
@@ -53,3 +52,9 @@ func annotate(data []byte, err error) error {
 
 	return fmt.Errorf("line: %d, position %d: %v", line, pos, err)
 }
+
+// UnmarshalPB is similar to Unmarshal but specifically for proto.Message to add type safety.
+func UnmarshalPB(data []byte, pb proto.Message) error {
+	opts := protojson.UnmarshalOptions{DiscardUnknown: true}
+	return annotate(data, opts.Unmarshal(data, pb))
+}

go/json2/unmarshal_test.go

@@ -91,3 +91,14 @@ func TestAnnotate(t *testing.T) {
 		require.Equal(t, tcase.err, err, "annotate(%s, %v) error", string(tcase.data), tcase.err)
 	}
 }
+
+func TestUnmarshalPB(t *testing.T) {
+	want := &emptypb.Empty{}
+	json, err := protojson.Marshal(want)
+	require.NoError(t, err)
+
+	var got emptypb.Empty
+	err = UnmarshalPB(json, &got)
+	require.NoError(t, err)
+	require.Equal(t, want, &got)
+}