Improve imports support (imports lookup)

* Add `--single-package-mode option`
    * Add `getMessageType` helper
    * Add `getProtoFile` helper
    * Add `examples/single-package-mode` example

Makefile

@@ -16,6 +16,7 @@ test:	install
 	cd examples/flow && make
 	cd examples/sitemap && make
 	cd examples/go-generate && make
+	cd examples/single-package-mode && make
 #	cd examples/go-kit && make
 
 .PHONY: docker.build

README.md

@@ -39,15 +39,21 @@ input.proto     templates/doc.txt.tmpl      templates/config.json.tmpl
 doc.txt         config.json
 ```
 
----
+### Options
 
-You can specify a custom `template_dir` or enable `debug`:
+You can specify custom options, as follow:
 
 ```console
 $> protoc --gotemplate_out=debug=true,template_dir=/path/to/template/directory:. input.proto
 ```
 
----
+| Option                | Default Value | Accepted Values           | Description
+|-----------------------|---------------|---------------------------|-----------------------
+| `template_dir`        | `./template`  | absolute or relative path | path to look for templates
+| `destination_dir`     | `.`           | absolute or relative path | base path to write output
+| `single-package-mode` | *false*       | `true` or `false`         | if *true*, `protoc` won't accept multiple packages to be compiled at once (*!= from `all`*), but will support `Message` lookup across the imported protobuf dependencies
+| `debug`               | *false*       | `true` or `false`         | if *true*, `protoc` will generate a more verbose output
+| `all`                 | *false*       | `true` or `false`         | if *true*, protobuf files without `Service` will also be parsed
 
 ##### Hints
 
@@ -61,13 +67,34 @@ See [examples](./examples).
 
 This project uses [Masterminds/sprig](https://github.com/Masterminds/sprig) library and additional functions to extend the builtin [text/template](https://golang.org/pkg/text/template) helpers.
 
-Non-exhaustive list of new helpers:
+Non-exhaustive list of new helpers:s
 
 * **all the functions from [sprig](https://github.com/Masterminds/sprig)**
 * `json`
 * `prettyjson`
 * `first`
 * `last`
+* `splitArray`
+* `upperFirst`
+* `lowerFirst`
+* `camelCase`
+* `lowerCamelCase`
+* `kebabCase`
+* `snakeCase`
+* `getProtoFile`
+* `getMessageType`
+* `getEnumValue`
+* `isFieldMessage`
+* `isFieldRepeated`
+* `goType`
+* `goTypeWithPackage`
+* `jsType`
+* `jsSuffixReserved`
+* `namespacedFlowType`
+* `httpVerb`
+* `httpPath`
+* `shortType`
+* `urlHasVarsFromMessage`
 
 See the project helpers for the complete list.
 

examples/single-package-mode/Makefile

@@ -0,0 +1,26 @@
+.PHONY: re
+re: clean build test
+
+.PHONY: build
+build:
+	@mkdir -p output
+
+	@# proto-gen-go
+	protoc -I./proto --go_out=plugins=grpc:output proto/aaa/aaa.proto
+	protoc -I./proto --go_out=plugins=grpc:output proto/bbb/bbb.proto
+	@rm -rf output/aaa output/bbb
+	@mv output/github.com/moul/protoc-gen-gotemplate/examples/single-package-mode/output/* output/
+	@rm -rf output/github.com
+
+	@# protoc-gen-gotemplate
+	protoc -I./proto --gotemplate_out=template_dir=templates,single-package-mode=true:output proto/bbb/bbb.proto
+	gofmt -w .
+
+.PHONY: test
+test:
+	go test -i ./output/...
+	go test -v ./output/...
+
+.PHONY: clean
+clean:
+	rm -rf output

examples/single-package-mode/output/aaa/aaa.pb.go

@@ -0,0 +1,84 @@
+// Code generated by protoc-gen-go.
+// source: aaa/aaa.proto
+// DO NOT EDIT!
+
+/*
+Package aaa is a generated protocol buffer package.
+
+It is generated from these files:
+	aaa/aaa.proto
+
+It has these top-level messages:
+	AaaRequest
+	AaaReply
+*/
+package aaa
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type AaaRequest struct {
+	Blah string `protobuf:"bytes,1,opt,name=blah" json:"blah,omitempty"`
+}
+
+func (m *AaaRequest) Reset()                    { *m = AaaRequest{} }
+func (m *AaaRequest) String() string            { return proto.CompactTextString(m) }
+func (*AaaRequest) ProtoMessage()               {}
+func (*AaaRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
+
+func (m *AaaRequest) GetBlah() string {
+	if m != nil {
+		return m.Blah
+	}
+	return ""
+}
+
+type AaaReply struct {
+	Error string `protobuf:"bytes,1,opt,name=error" json:"error,omitempty"`
+}
+
+func (m *AaaReply) Reset()                    { *m = AaaReply{} }
+func (m *AaaReply) String() string            { return proto.CompactTextString(m) }
+func (*AaaReply) ProtoMessage()               {}
+func (*AaaReply) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
+
+func (m *AaaReply) GetError() string {
+	if m != nil {
+		return m.Error
+	}
+	return ""
+}
+
+func init() {
+	proto.RegisterType((*AaaRequest)(nil), "the.aaa.package.AaaRequest")
+	proto.RegisterType((*AaaReply)(nil), "the.aaa.package.AaaReply")
+}
+
+func init() { proto.RegisterFile("aaa/aaa.proto", fileDescriptor0) }
+
+var fileDescriptor0 = []byte{
+	// 172 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x2c, 0x8e, 0x31, 0x0b, 0xc2, 0x30,
+	0x10, 0x46, 0x29, 0xa8, 0x68, 0x40, 0x84, 0xe0, 0xe0, 0x58, 0x3a, 0xb9, 0xa4, 0x19, 0xfc, 0x05,
+	0xba, 0x8b, 0xd0, 0xd1, 0xed, 0x5a, 0x8f, 0xb4, 0x78, 0xe9, 0xc5, 0xf4, 0x02, 0xfa, 0xef, 0xc5,
+	0xd8, 0xed, 0x1e, 0xbc, 0xe3, 0x7b, 0x6a, 0x0b, 0x00, 0x16, 0x00, 0xea, 0x10, 0x59, 0x58, 0xef,
+	0xa4, 0xc7, 0x3a, 0x23, 0x74, 0x4f, 0x70, 0x58, 0x95, 0x4a, 0x9d, 0x01, 0x1a, 0x7c, 0x25, 0x9c,
+	0x44, 0x6b, 0xb5, 0x68, 0x09, 0xfa, 0x43, 0x51, 0x16, 0xc7, 0x4d, 0x93, 0xef, 0xaa, 0x54, 0xeb,
+	0x6c, 0x04, 0xfa, 0xe8, 0xbd, 0x5a, 0x62, 0x8c, 0x1c, 0x67, 0xe1, 0x0f, 0x97, 0xdb, 0xfd, 0xea,
+	0x06, 0xe9, 0x53, 0x5b, 0x77, 0xec, 0xad, 0xe7, 0x44, 0x36, 0xaf, 0x75, 0xc6, 0xe1, 0x68, 0x1c,
+	0x0b, 0xfa, 0x40, 0x20, 0x68, 0xf1, 0x0d, 0x3e, 0x10, 0x4e, 0x76, 0x1a, 0x46, 0x47, 0x68, 0xe6,
+	0x08, 0xe3, 0xf9, 0x81, 0x96, 0x93, 0x84, 0x24, 0xbf, 0xd6, 0x76, 0x95, 0xdf, 0x4f, 0xdf, 0x00,
+	0x00, 0x00, 0xff, 0xff, 0x93, 0x24, 0x48, 0x9c, 0xbd, 0x00, 0x00, 0x00,
+}

examples/single-package-mode/output/bbb/bbb.pb.go

@@ -0,0 +1,200 @@
+// Code generated by protoc-gen-go.
+// source: bbb/bbb.proto
+// DO NOT EDIT!
+
+/*
+Package bbb is a generated protocol buffer package.
+
+It is generated from these files:
+	bbb/bbb.proto
+
+It has these top-level messages:
+	BbbRequest
+	BbbReply
+*/
+package bbb
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import the_aaa_package "github.com/moul/protoc-gen-gotemplate/examples/single-package-mode/output/aaa"
+
+import (
+	context "golang.org/x/net/context"
+	grpc "google.golang.org/grpc"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type BbbRequest struct {
+	Enable bool `protobuf:"varint,1,opt,name=enable" json:"enable,omitempty"`
+}
+
+func (m *BbbRequest) Reset()                    { *m = BbbRequest{} }
+func (m *BbbRequest) String() string            { return proto.CompactTextString(m) }
+func (*BbbRequest) ProtoMessage()               {}
+func (*BbbRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
+
+func (m *BbbRequest) GetEnable() bool {
+	if m != nil {
+		return m.Enable
+	}
+	return false
+}
+
+type BbbReply struct {
+	Done bool `protobuf:"varint,1,opt,name=done" json:"done,omitempty"`
+}
+
+func (m *BbbReply) Reset()                    { *m = BbbReply{} }
+func (m *BbbReply) String() string            { return proto.CompactTextString(m) }
+func (*BbbReply) ProtoMessage()               {}
+func (*BbbReply) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
+
+func (m *BbbReply) GetDone() bool {
+	if m != nil {
+		return m.Done
+	}
+	return false
+}
+
+func init() {
+	proto.RegisterType((*BbbRequest)(nil), "the.bbb.package.BbbRequest")
+	proto.RegisterType((*BbbReply)(nil), "the.bbb.package.BbbReply")
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// Client API for BbbService service
+
+type BbbServiceClient interface {
+	Aaa(ctx context.Context, in *the_aaa_package.AaaRequest, opts ...grpc.CallOption) (*the_aaa_package.AaaReply, error)
+	Bbb(ctx context.Context, in *BbbRequest, opts ...grpc.CallOption) (*BbbReply, error)
+}
+
+type bbbServiceClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewBbbServiceClient(cc *grpc.ClientConn) BbbServiceClient {
+	return &bbbServiceClient{cc}
+}
+
+func (c *bbbServiceClient) Aaa(ctx context.Context, in *the_aaa_package.AaaRequest, opts ...grpc.CallOption) (*the_aaa_package.AaaReply, error) {
+	out := new(the_aaa_package.AaaReply)
+	err := grpc.Invoke(ctx, "/the.bbb.package.BbbService/Aaa", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *bbbServiceClient) Bbb(ctx context.Context, in *BbbRequest, opts ...grpc.CallOption) (*BbbReply, error) {
+	out := new(BbbReply)
+	err := grpc.Invoke(ctx, "/the.bbb.package.BbbService/Bbb", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for BbbService service
+
+type BbbServiceServer interface {
+	Aaa(context.Context, *the_aaa_package.AaaRequest) (*the_aaa_package.AaaReply, error)
+	Bbb(context.Context, *BbbRequest) (*BbbReply, error)
+}
+
+func RegisterBbbServiceServer(s *grpc.Server, srv BbbServiceServer) {
+	s.RegisterService(&_BbbService_serviceDesc, srv)
+}
+
+func _BbbService_Aaa_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(the_aaa_package.AaaRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(BbbServiceServer).Aaa(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/the.bbb.package.BbbService/Aaa",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(BbbServiceServer).Aaa(ctx, req.(*the_aaa_package.AaaRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _BbbService_Bbb_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(BbbRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(BbbServiceServer).Bbb(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/the.bbb.package.BbbService/Bbb",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(BbbServiceServer).Bbb(ctx, req.(*BbbRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+var _BbbService_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "the.bbb.package.BbbService",
+	HandlerType: (*BbbServiceServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "Aaa",
+			Handler:    _BbbService_Aaa_Handler,
+		},
+		{
+			MethodName: "Bbb",
+			Handler:    _BbbService_Bbb_Handler,
+		},
+	},
+	Streams:  []grpc.StreamDesc{},
+	Metadata: "bbb/bbb.proto",
+}
+
+func init() { proto.RegisterFile("bbb/bbb.proto", fileDescriptor0) }
+
+var fileDescriptor0 = []byte{
+	// 242 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x6c, 0x90, 0x41, 0x4b, 0x03, 0x31,
+	0x10, 0x85, 0x59, 0x2a, 0xa5, 0x04, 0x8a, 0x90, 0x83, 0x68, 0x05, 0x91, 0xe2, 0xc1, 0xcb, 0x26,
+	0xa0, 0xe7, 0x1e, 0xba, 0x77, 0x11, 0xea, 0xcd, 0xdb, 0xcc, 0x76, 0x48, 0x17, 0x93, 0x9d, 0xd8,
+	0x9d, 0x88, 0xfd, 0x0b, 0xfe, 0x6a, 0xd9, 0x34, 0xa2, 0x60, 0x6f, 0x19, 0xde, 0xbc, 0xf7, 0xbd,
+	0x8c, 0x9a, 0x23, 0xa2, 0x45, 0x44, 0x13, 0xf7, 0x2c, 0xac, 0xcf, 0x65, 0x47, 0x26, 0x8f, 0xd0,
+	0xbe, 0x81, 0xa3, 0xc5, 0x1c, 0x00, 0x2c, 0x00, 0x1c, 0xf5, 0xe5, 0x9d, 0x52, 0x0d, 0xe2, 0x86,
+	0xde, 0x13, 0x0d, 0xa2, 0x2f, 0xd4, 0x94, 0x7a, 0x40, 0x4f, 0x97, 0xd5, 0x6d, 0x75, 0x3f, 0xdb,
+	0x94, 0x69, 0x79, 0xa3, 0x66, 0x79, 0x2b, 0xfa, 0x83, 0xd6, 0xea, 0x6c, 0xcb, 0xfd, 0xcf, 0x46,
+	0x7e, 0x3f, 0x7c, 0x55, 0x39, 0xe6, 0x85, 0xf6, 0x1f, 0x5d, 0x4b, 0x7a, 0xa5, 0x26, 0x6b, 0x00,
+	0x7d, 0x6d, 0x46, 0x78, 0x66, 0x1d, 0xe1, 0x66, 0x0d, 0x50, 0x50, 0x8b, 0xab, 0xd3, 0xe2, 0x48,
+	0x58, 0xa9, 0x49, 0x83, 0x58, 0xec, 0x7f, 0xba, 0x9b, 0xdf, 0xa6, 0xc5, 0xfe, 0x4f, 0x8c, 0xfe,
+	0xd0, 0x3c, 0xbf, 0x3e, 0xb9, 0x4e, 0x76, 0x09, 0x4d, 0xcb, 0xc1, 0x06, 0x4e, 0xde, 0xe6, 0xbf,
+	0xb6, 0xb5, 0xa3, 0xbe, 0x76, 0x2c, 0x14, 0xa2, 0x07, 0x21, 0x4b, 0x9f, 0x10, 0xa2, 0xa7, 0xc1,
+	0x0e, 0x5d, 0xef, 0x3c, 0xd5, 0x25, 0xa9, 0x0e, 0xbc, 0x25, 0xcb, 0x49, 0x62, 0x92, 0xf1, 0x92,
+	0x38, 0xcd, 0xf6, 0xc7, 0xef, 0x00, 0x00, 0x00, 0xff, 0xff, 0xe0, 0xe1, 0x26, 0xcb, 0x5b, 0x01,
+	0x00, 0x00,
+}

examples/single-package-mode/output/bbb/service.go

@@ -0,0 +1,19 @@
+// file generated with protoc-gen-gotemplate
+package bbb
+
+import (
+	"fmt"
+
+	"github.com/moul/protoc-gen-gotemplate/examples/single-package-mode/output/aaa"
+	"golang.org/x/net/context"
+)
+
+type Service struct{}
+
+func (service Service) Aaa(ctx context.Context, input *aaa.AaaRequest) (*aaa.AaaReply, error) {
+	return nil, fmt.Errorf("method not implemented")
+}
+
+func (service Service) Bbb(ctx context.Context, input *BbbRequest) (*BbbReply, error) {
+	return nil, fmt.Errorf("method not implemented")
+}

examples/single-package-mode/proto/aaa/aaa.proto

@@ -0,0 +1,12 @@
+syntax = "proto3";
+
+option go_package = "github.com/moul/protoc-gen-gotemplate/examples/single-package-mode/output/aaa";
+
+package the.aaa.package;
+
+message AaaRequest {
+  string blah = 1;
+}
+message AaaReply {
+  string error = 1;
+}

examples/single-package-mode/proto/bbb/bbb.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package the.bbb.package;
+
+option go_package = "github.com/moul/protoc-gen-gotemplate/examples/single-package-mode/output/bbb";
+
+import "aaa/aaa.proto";
+
+service BbbService {
+  rpc Aaa(the.aaa.package.AaaRequest) returns (the.aaa.package.AaaReply);
+  rpc Bbb(BbbRequest) returns (BbbReply);
+}
+
+message BbbRequest {
+  bool enable = 1;
+}
+message BbbReply {
+  bool done = 1;
+}

examples/single-package-mode/templates/{{.File.Name|dir}}/service.go.tmpl

@@ -0,0 +1,26 @@
+// file generated with protoc-gen-gotemplate
+package {{.File.Name | dir}}
+
+{{- $file := .File}}
+{{- $currentFile := $file.Name | getProtoFile}}
+
+import (
+	"fmt"
+
+	"golang.org/x/net/context"
+
+	{{- range .File.Dependency}}
+	{{- $dependency := . | getProtoFile}}
+	{{$dependency.GoPkg}}
+	{{end}}
+)
+
+type Service struct {}
+
+{{- range .Service.Method}}
+{{- $in := .InputType | getMessageType $file}}
+{{- $out := .OutputType | getMessageType $file}}
+func (service Service) {{.Name}}(ctx context.Context, input *{{$in.GoType $currentFile.GoPkg.Path}}) (*{{$out.GoType $currentFile.GoPkg.Path}}, error) {
+	return nil, fmt.Errorf("method not implemented")
+}
+{{end}}

helpers.go

@@ -8,10 +8,10 @@ import (
 	"text/template"
 
 	"github.com/Masterminds/sprig"
-	"github.com/huandu/xstrings"
-
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+	ggdescriptor "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
+	"github.com/huandu/xstrings"
 	options "google.golang.org/genproto/googleapis/api/annotations"
 )
 
@@ -64,6 +64,7 @@ var ProtoHelpersFuncMap = template.FuncMap{
 		return strings.Replace(xstrings.ToSnakeCase(s), "_", "-", -1)
 	},
 	"snakeCase":             xstrings.ToSnakeCase,
+	"getProtoFile":          getProtoFile,
 	"getMessageType":        getMessageType,
 	"getEnumValue":          getEnumValue,
 	"isFieldMessage":        isFieldMessage,
@@ -85,17 +86,37 @@ func init() {
 	}
 }
 
-func getMessageType(f *descriptor.FileDescriptorProto, name string) *descriptor.DescriptorProto {
+func getProtoFile(name string) *ggdescriptor.File {
+	if registry == nil {
+		return nil
+	}
+	file, err := registry.LookupFile(name)
+	if err != nil {
+		panic(err)
+	}
+	return file
+}
+
+func getMessageType(f *descriptor.FileDescriptorProto, name string) *ggdescriptor.Message {
+	if registry != nil {
+		msg, err := registry.LookupMsg(".", name)
+		if err != nil {
+			panic(err)
+		}
+		return msg
+	}
+
 	// name is in the form .packageName.MessageTypeName.InnerMessageTypeName...
 	// e.g. .article.ProductTag
 	splits := strings.Split(name, ".")
 	target := splits[len(splits)-1]
 	for _, m := range f.MessageType {
 		if target == *m.Name {
-			return m
+			return &ggdescriptor.Message{
+				DescriptorProto: m,
+			}
 		}
 	}
-
 	return nil
 }
 

main.go

@@ -9,6 +9,11 @@ import (
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/protoc-gen-go/generator"
 	"github.com/golang/protobuf/protoc-gen-go/plugin"
+	ggdescriptor "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
+)
+
+var (
+	registry *ggdescriptor.Registry // some helpers need access to registry
 )
 
 func main() {
@@ -30,10 +35,13 @@ func main() {
 	g.CommandLineParameters(g.Request.GetParameter())
 
 	// Parse parameters
-	templateDir := "./templates"
+	var (
-	destinationDir := "."
+		templateDir       = "./templates"
-	debug := false
+		destinationDir    = "."
-	all := false
+		debug             = false
+		all               = false
+		singlePackageMode = false
+	)
 	if parameter := g.Request.GetParameter(); parameter != "" {
 		for _, param := range strings.Split(parameter, ",") {
 			parts := strings.Split(param, "=")
@@ -48,6 +56,15 @@ func main() {
 			case "destination_dir":
 				destinationDir = parts[1]
 				break
+			case "single-package-mode":
+				switch strings.ToLower(parts[1]) {
+				case "true", "t":
+					singlePackageMode = true
+				case "false", "f":
+				default:
+					log.Printf("Err: invalid value for single-package-mode: %q", parts[1])
+				}
+				break
 			case "debug":
 				switch strings.ToLower(parts[1]) {
 				case "true", "t":
@@ -74,17 +91,29 @@ func main() {
 
 	tmplMap := make(map[string]*plugin_go.CodeGeneratorResponse_File)
 	concatOrAppend := func(file *plugin_go.CodeGeneratorResponse_File) {
-		if val, ok := tmplMap[*file.Name]; ok {
+		if val, ok := tmplMap[file.GetName()]; ok {
-			*val.Content += *file.Content
+			*val.Content += file.GetContent()
 		} else {
-			tmplMap[*file.Name] = file
+			tmplMap[file.GetName()] = file
 			g.Response.File = append(g.Response.File, file)
 		}
 	}
 
+	if singlePackageMode {
+		registry = ggdescriptor.NewRegistry()
+		if err := registry.Load(g.Request); err != nil {
+			g.Error(err, "registry: failed to load the request")
+		}
+	}
+
 	// Generate the encoders
 	for _, file := range g.Request.GetProtoFile() {
 		if all {
+			if singlePackageMode {
+				if _, err := registry.LookupFile(file.GetName()); err != nil {
+					g.Error(err, "registry: failed to lookup file %q", file.GetName())
+				}
+			}
 			encoder := NewGenericTemplateBasedEncoder(templateDir, file, debug, destinationDir)
 			for _, tmpl := range encoder.Files() {
 				concatOrAppend(tmpl)