protoc-go-inject-field

This is a fork version of https://github.com/favadi/protoc-go-inject-field. Go there for original code and my thanks to favadi (Diep Pham) for developing it in the first place.

This version includes tags on custom fields and was updated using go mod.

Why?

Sometimes it is useful to have custom unexported fields in generated golang codes, but this use case is unsupported. This tool injects custom fields along with its getter/setter methods to generated .pb.go files.

Install

go get github.com/joaosobral/protoc-go-inject-field

Usage

Add one or more comments with syntax // @inject_field: field_name field_type before messages.

Example:

// file: test.proto
syntax = "proto3";

package pb;

// @inject_field: age int
// @inject_field: spouse *Human
// @inject_field: IgnoreMe
message Human {
    string name = 1;
}

// @inject_field: model string
message Robot {
    string name = 1;
}

message Alien {
    string name = 1;
}

Generate with protoc command.

protoc --go_out=. test.proto

Run protoc-go-inject-field with generated file.

protoc-go-inject-field -input=./test.pb.go

The custom fields will be injected along with its getter/setter methods.

diff --git a/playground.pb.go.orig b/playground.pb.go
index 679c243..5b4ec2f 100644
--- a/playground.pb.go.orig
+++ b/playground.pb.go
@@ -38,6 +38,24 @@ const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 // @inject_field: IgnoreMe
 type Human struct {
     Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+
+    // custom fields
+    age int
+    spouse *Human
+}
+
+// custom fields getter/setter
+func (m *Human) Age() int {
+    return m.age
+}
+func (m *Human) SetAge(in int){
+    m.age = in
+}
+func (m *Human) Spouse() *Human {
+    return m.spouse
+}
+func (m *Human) SetSpouse(in *Human){
+    m.spouse = in
 }
 
 func (m *Human) Reset()                    { *m = Human{} }
@@ -48,6 +66,17 @@ func (*Human) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
 // @inject_field: model string
 type Robot struct {
     Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+
+    // custom fields
+    model string
+}
+
+// custom fields getter/setter
+func (m *Robot) Model() string {
+    return m.model
+}
+func (m *Robot) SetModel(in string){
+    m.model = in
 }
 
 func (m *Robot) Reset()                    { *m = Robot{} }