pgs (field presence): nit/style fixes

Signed-off-by: Sarthak Gupta <signed@sarthak.sh>

field.go

@@ -22,24 +22,24 @@ type Field interface {
 
 	// InRealOneOf returns true if the field is in a OneOf of the parent Message.
 	// This will return false for synthetic oneofs, and will only include 'real' oneofs.
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md
 	InRealOneOf() bool
 
-	// OneOf returns the OneOf that this field is apart of. Nil is returned if
+	// OneOf returns the OneOf that this field is a part of. Nil is returned if
 	// the field is not within a OneOf.
 	OneOf() OneOf
 
 	// Type returns the FieldType of this Field.
 	Type() FieldType
 
 	// HasPresence returns true for all fields that have explicit presence as defined by:
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md
 	HasPresence() bool
 
-	// Optional returns whether or not the field is labeled as optional.
-	Optional() bool
+	// HasOptionalKeyword returns whether the field is labeled as optional.
+	HasOptionalKeyword() bool
 
-	// Required returns whether or not the field is labeled as required. This
+	// Required returns whether the field is labeled as required. This
 	// will only be true if the syntax is proto2.
 	Required() bool
 
@@ -69,25 +69,33 @@ func (f *field) SourceCodeInfo() SourceCodeInfo               { return f.info }
 func (f *field) Descriptor() *descriptor.FieldDescriptorProto { return f.desc }
 func (f *field) Message() Message                             { return f.msg }
 func (f *field) InOneOf() bool                                { return f.oneof != nil }
-func (f *field) InRealOneOf() bool                            { return f.InOneOf() && !f.desc.GetProto3Optional() }
 func (f *field) OneOf() OneOf                                 { return f.oneof }
 func (f *field) Type() FieldType                              { return f.typ }
 func (f *field) setMessage(m Message)                         { f.msg = m }
 func (f *field) setOneOf(o OneOf)                             { f.oneof = o }
 
+func (f *field) InRealOneOf() bool {
+	return f.InOneOf() && !f.desc.GetProto3Optional()
+}
+
 func (f *field) HasPresence() bool {
-	if f.Type().IsRepeated() || f.Type().IsMap() {
-		return false
+	if f.InOneOf() {
+		return true
+	}
+
+	if f.Type().IsEmbed() {
+		return true
 	}
 
-	if f.Syntax() == Proto3 && !f.Optional() && !(f.Type().IsEmbed() || f.InRealOneOf()) {
-		return false
+	if f.HasOptionalKeyword() ||
+		(f.Syntax() == Proto2 && !f.Type().IsRepeated() && !f.Type().IsMap()) {
+		return true
 	}
 
-	return true
+	return false
 }
 
-func (f *field) Optional() bool {
+func (f *field) HasOptionalKeyword() bool {
 	if f.Syntax() == Proto3 {
 		return f.desc.GetProto3Optional()
 	}

field_test.go

@@ -115,7 +115,7 @@ func TestField_InRealOneOf(t *testing.T) {
 func TestField_HasPresence(t *testing.T) {
 	t.Parallel()
 
-	f := &field{}
+	f := dummyField()
 	f.addType(&repT{scalarT: &scalarT{}})
 	assert.False(t, f.HasPresence())
 
@@ -137,19 +137,19 @@ func TestField_Optional(t *testing.T) {
 	optLabel := descriptor.FieldDescriptorProto_LABEL_OPTIONAL
 
 	f := &field{msg: &msg{parent: dummyFile()}}
-	assert.False(t, f.Optional())
+	assert.False(t, f.HasOptionalKeyword())
 
 	f.desc = &descriptor.FieldDescriptorProto{Label: &optLabel}
-	assert.False(t, f.Optional())
+	assert.False(t, f.HasOptionalKeyword())
 
 	f = dummyField()
-	assert.False(t, f.Optional())
+	assert.False(t, f.HasOptionalKeyword())
 
 	f = dummyOneOfField(false)
-	assert.False(t, f.Optional())
+	assert.False(t, f.HasOptionalKeyword())
 
 	f = dummyOneOfField(true)
-	assert.True(t, f.Optional())
+	assert.True(t, f.HasOptionalKeyword())
 }
 
 func TestField_Type(t *testing.T) {

field_type.go

@@ -83,7 +83,7 @@ func (s *scalarT) Element() FieldTypeElem { return nil }
 func (s *scalarT) Key() FieldTypeElem     { return nil }
 
 func (s *scalarT) IsOptional() bool {
-	return s.fld.Optional()
+	return s.fld.HasOptionalKeyword()
 }
 
 func (s *scalarT) IsRequired() bool {

init_option.go

@@ -1,7 +1,6 @@
 package pgs
 
 import (
-	"google.golang.org/protobuf/types/pluginpb"
 	"io"
 	"os"
 
@@ -49,11 +48,10 @@ func BiDirectional() InitOption {
 	return func(g *Generator) { g.workflow = &onceWorkflow{workflow: &standardWorkflow{BiDi: true}} }
 }
 
-// SupportProto3Optional adds support for proto3 field presence.
-// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/implementing_proto3_presence.md#signaling-that-your-code-generator-supports-proto3-optional
-func SupportProto3Optional() InitOption {
+// SupportedFeatures allows defining protoc features to enable / disable.
+// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/implementing_proto3_presence.md#signaling-that-your-code-generator-supports-proto3-optional
+func SupportedFeatures(feat *uint64) InitOption {
 	return func(g *Generator) {
-		p3Optional := uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPTIONAL)
-		g.persister.SetSupportedField(&p3Optional)
+		g.persister.SetSupportedFeatures(feat)
 	}
 }

message.go

@@ -30,15 +30,15 @@ type Message interface {
 	OneOfFields() []Field
 
 	// SyntheticOneOfFields returns only the fields contained within synthetic OneOf blocks.
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md
 	SyntheticOneOfFields() []Field
 
 	// OneOfs returns the OneOfs contained within this Message.
 	OneOfs() []OneOf
 
 	// RealOneOfs returns the OneOfs contained within this Message.
 	// This excludes synthetic OneOfs.
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md
 	RealOneOfs() []OneOf
 
 	// Extensions returns all of the Extensions applied to this Message.

oneof.go

@@ -20,7 +20,7 @@ type OneOf interface {
 	Fields() []Field
 
 	// IsSynthetic returns true if this is a proto3 synthetic oneof.
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md
 	IsSynthetic() bool
 
 	setMessage(m Message)

persister.go

@@ -13,29 +13,29 @@ import (
 type persister interface {
 	SetDebugger(d Debugger)
 	SetFS(fs afero.Fs)
-	SetSupportedField(f *uint64)
+	SetSupportedFeatures(f *uint64)
 	AddPostProcessor(proc ...PostProcessor)
 	Persist(a ...Artifact) *plugin_go.CodeGeneratorResponse
 }
 
 type stdPersister struct {
 	Debugger
 
-	fs             afero.Fs
-	procs          []PostProcessor
-	supportedField *uint64
+	fs                afero.Fs
+	procs             []PostProcessor
+	supportedFeatures *uint64
 }
 
 func newPersister() *stdPersister { return &stdPersister{fs: afero.NewOsFs()} }
 
 func (p *stdPersister) SetDebugger(d Debugger)                 { p.Debugger = d }
 func (p *stdPersister) SetFS(fs afero.Fs)                      { p.fs = fs }
-func (p *stdPersister) SetSupportedField(f *uint64)            { p.supportedField = f }
+func (p *stdPersister) SetSupportedFeatures(f *uint64)         { p.supportedFeatures = f }
 func (p *stdPersister) AddPostProcessor(proc ...PostProcessor) { p.procs = append(p.procs, proc...) }
 
 func (p *stdPersister) Persist(arts ...Artifact) *plugin_go.CodeGeneratorResponse {
 	resp := new(plugin_go.CodeGeneratorResponse)
-	resp.SupportedFeatures = p.supportedField
+	resp.SupportedFeatures = p.supportedFeatures
 
 	for _, a := range arts {
 		switch a := a.(type) {

proto.go

@@ -16,7 +16,7 @@ const (
 	// Proto3 syntax permits the use of "optional" field presence. Non optional fields default to the zero
 	// 	value of that particular type if not defined.
 	// Most of the field types in the generated go structs are value types.
-	// See: https://github.com/protocolbuffers/protobuf/blob/master/docs/field_presence.md#presence-in-proto3-apis
+	// See: https://github.com/protocolbuffers/protobuf/blob/v3.17.0/docs/field_presence.md#presence-in-proto3-apis
 	Proto3 Syntax = "proto3"
 )