protoc-gen-apidocs: Support proto3 optional

Author: tmc

go.mod

@@ -4,7 +4,7 @@ go 1.17
 
 require (
 	github.com/Masterminds/sprig v2.22.0+incompatible
-	google.golang.org/protobuf v1.27.1
+	google.golang.org/protobuf v1.28.1
 )
 
 require (

go.sum

@@ -24,5 +24,7 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
+google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -15,6 +15,7 @@ import (
 	"github.com/Masterminds/sprig"
 	"google.golang.org/protobuf/compiler/protogen"
 	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/types/pluginpb"
 )
 
 func main() {
@@ -27,6 +28,7 @@ func main() {
 		ParamFunc: flags.Set,
 	}
 	opts.Run(func(gen *protogen.Plugin) error {
+		gen.SupportedFeatures = uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPTIONAL)
 		genOpts := GenOpts{
 			Format:      *format,
 			TemplateDir: *templates,