support nested extends

Author: joesonw

example/output.proto

@@ -5,21 +5,17 @@ option go_package = 'generated/proto;pb';
 
 package example.com;
 
-message Base {
-    int64 id = 1;
-    int64 createdAt = 2;
-    int64 updatedAt = 3;
-}
-
-
 message groups {
     message Group {
 
+        // ↓↓↓↓↓ extends Intermediate
         // ↓↓↓↓↓ extends Base
         int64 id = 1;
+        // ↑↑↑↑↑ extends Base
+
         int64 createdAt = 2;
         int64 updatedAt = 3;
-        // ↑↑↑↑↑ extends Base
+        // ↑↑↑↑↑ extends Intermediate
 
         string name = 11;
         repeated users.User users = 12;
@@ -30,11 +26,14 @@ message groups {
 message users {
     message User {
 
+        // ↓↓↓↓↓ extends Intermediate
         // ↓↓↓↓↓ extends Base
         int64 id = 1;
+        // ↑↑↑↑↑ extends Base
+
         int64 createdAt = 2;
         int64 updatedAt = 3;
-        // ↑↑↑↑↑ extends Base
+        // ↑↑↑↑↑ extends Intermediate
 
         string name = 11;
         string email = 12;
@@ -44,3 +43,18 @@ message users {
 
 }
 
+message Base {
+    int64 id = 1;
+}
+
+message Intermediate {
+
+    // ↓↓↓↓↓ extends Base
+    int64 id = 1;
+    // ↑↑↑↑↑ extends Base
+
+    int64 createdAt = 2;
+    int64 updatedAt = 3;
+}
+
+

example/proto/base.proto

@@ -5,6 +5,4 @@ package example.com;
 
 message Base {
     int64 id = 1;
-    int64 createdAt = 2;
-    int64 updatedAt = 3;
 }

example/proto/group.proto

@@ -4,11 +4,10 @@ option go_package = 'generated/proto;pb';
 package example.com.groups;
 
 import "proto/user.proto";
-import "proto/base.proto";
 import "oneproto.proto";
 
 message Group {
-  option (oneproto.extends) = 'example.com.Base';
+  option (oneproto.extends) = 'example.com.Intermediate';
 
   string name = 11;
   repeated users.User users = 12;

example/proto/intermediate.proto

@@ -0,0 +1,13 @@
+syntax = 'proto3';
+option go_package = 'generated/proto;pb';
+
+package example.com;
+
+import "oneproto.proto";
+
+message Intermediate {
+    option (oneproto.extends) = 'example.com.Base';
+
+    int64 createdAt = 2;
+    int64 updatedAt = 3;
+}

example/proto/user.proto

@@ -6,8 +6,9 @@ package example.com.users;
 import "proto/group.proto";
 import "oneproto.proto";
 
+
 message User {
-    option (oneproto.extends) = 'example.com.Base';
+    option (oneproto.extends) = 'example.com.Intermediate';
 
     string name = 11;
     string email = 12;

main.go

@@ -195,18 +195,7 @@ func generateMessage(buf *Buffer, indentLevel int, message *descriptorpb.Descrip
 	indent := strings.Repeat(" ", indentLevel*4)
 	buf.Printf("%smessage %s {", indent, message.GetName())
 	generateHeadOptions(buf, indent, message.GetOptions().GetUninterpretedOption())
-	for _, opt := range message.GetOptions().GetUninterpretedOption() {
-		if isOptionOneProtoExtends(opt) {
-			name := trimPackageFromName(string(opt.GetStringValue()))
-			buf.Printf("%s    // ↓↓↓↓↓ extends %s", indent, name)
-			parent := allMessageDescriptors[name]
-			for _, field := range parent.GetField() {
-				buf.Printf("%s    %s %s = %d%s;", indent, stringifyField(message, field), field.GetName(), field.GetNumber(), stringifyValueOptions(field.GetOptions().GetUninterpretedOption()))
-			}
-			buf.Printf("%s    // ↑↑↑↑↑ extends %s", indent, name)
-			buf.Printf("")
-		}
-	}
+	generateExtendedMessage(buf, indentLevel, message)
 	for _, field := range message.GetField() {
 		buf.Printf("%s    %s %s = %d%s;", indent, stringifyField(message, field), field.GetName(), field.GetNumber(), stringifyValueOptions(field.GetOptions().GetUninterpretedOption()))
 	}
@@ -226,6 +215,23 @@ func generateMessage(buf *Buffer, indentLevel int, message *descriptorpb.Descrip
 	buf.Printf("%s}", indent)
 }
 
+func generateExtendedMessage(buf *Buffer, indentLevel int, message *descriptorpb.DescriptorProto) {
+	indent := strings.Repeat(" ", indentLevel*4)
+	for _, opt := range message.GetOptions().GetUninterpretedOption() {
+		if isOptionOneProtoExtends(opt) {
+			name := trimPackageFromName(string(opt.GetStringValue()))
+			buf.Printf("%s    // ↓↓↓↓↓ extends %s", indent, name)
+			parent := allMessageDescriptors[name]
+			generateExtendedMessage(buf, indentLevel, parent)
+			for _, field := range parent.GetField() {
+				buf.Printf("%s    %s %s = %d%s;", indent, stringifyField(message, field), field.GetName(), field.GetNumber(), stringifyValueOptions(field.GetOptions().GetUninterpretedOption()))
+			}
+			buf.Printf("%s    // ↑↑↑↑↑ extends %s", indent, name)
+			buf.Printf("")
+		}
+	}
+}
+
 func generateHeadOptions(buf *Buffer, indent string, options []*descriptorpb.UninterpretedOption) {
 	if len(options) == 0 {
 		return

oneproto.proto

@@ -6,5 +6,5 @@ package oneproto;
 import 'google/protobuf/descriptor.proto';
 
 extend google.protobuf.MessageOptions {
-    string extends = 9099;
+    string extends = 2099;
 }