solution for the issue: lyft/protoc-gen-star#64

check.proto

@@ -6,6 +6,10 @@ import "type.proto";
 
 message Check {
     string field_1 = 1 [(main.rule1).type.one = "rule1.type.one", (main.rule1).type.two = "rule1.type.two"];
+    // issue
     string field_2 = 2 [(main.rule2).type.one = "rule2.type.one", (main.rule2).type.two = "rule2.type.two"];
     string field_3 = 3 [(main.rule2).type.two = "rule2.type.two", (main.rule2).type.one = "rule2.type.one"];
+    // solution
+    string field_4 = 4 [(main.rule2).type = {one: "rule2.type.one" two: "rule2.type.two"}];
+    string field_5 = 5 [(main.rule2).type = {two: "rule2.type.two" one: "rule2.type.one"}];
 }

main.go

@@ -6,7 +6,7 @@ import (
 	pgs "github.com/lyft/protoc-gen-star"
 )
 
-//TODO: GO111MODULE=on go build -o bin/protoc-gen-sample
+//go:generate go build -o bin/protoc-gen-sample
 //go:generate protoc -I . type.proto --go_out=plugins=grpc:.
 //go:generate protoc -I . check.proto --plugin=bin/protoc-gen-sample --sample_out=:.
 

sample.txt

@@ -1,3 +1,5 @@
 field_1 one:"rule1.type.one" two:"rule1.type.two" 
 field_2 two:"rule2.type.two" 
 field_3 one:"rule2.type.one" 
+field_4 one:"rule2.type.one" two:"rule2.type.two" 
+field_5 one:"rule2.type.one" two:"rule2.type.two"