feat: support generate nested struct for slim template (#101)

args.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/cloudwego/thriftgo/generator"
 	"github.com/cloudwego/thriftgo/generator/backend"
+	"github.com/cloudwego/thriftgo/generator/golang"
 	"github.com/cloudwego/thriftgo/plugin"
 )
 
@@ -99,7 +100,12 @@ func (a *Arguments) Targets() (specs []*generator.LangSpec, err error) {
 		if err != nil {
 			return nil, err
 		}
-
+		opts, err := a.checkOptions(desc.Options)
+		if err != nil {
+			return nil, err
+		}
+		// checkOptions may modify the content of the options
+		desc.Options = opts
 		spec := &generator.LangSpec{
 			Language: desc.Name,
 			Options:  desc.Options,
@@ -109,6 +115,33 @@ func (a *Arguments) Targets() (specs []*generator.LangSpec, err error) {
 	return
 }
 
+// checkOptions used to validate the command parameters.
+func (a *Arguments) checkOptions(opts []plugin.Option) ([]plugin.Option, error) {
+	params := plugin.Pack(opts)
+	cu := golang.NewCodeUtils(backend.DummyLogFunc())
+	cu.HandleOptions(params)
+	if cu.Features().EnableNestedStruct {
+		// In nested mode, if template is not 'slim', it is automatically converted to slim
+		if cu.Template() != "slim" {
+			found := false
+			for _, opt := range opts {
+				if opt.Name == "template" {
+					log.Printf("[WARN] EnableNestedStruct is only available under the \"slim\" template, so adapt the template to \"slim\"")
+					opt.Desc = "slim"
+					found = true
+					break
+				}
+			}
+			if !found {
+				log.Printf("[WARN] EnableNestedStruct is only available under the \"slim\" template, so adapt the template to \"slim\"")
+				opts = append(opts, plugin.Option{Name: "template", Desc: "slim"})
+			}
+
+		}
+	}
+	return opts, nil
+}
+
 // MakeLogFunc creates logging functions according to command line flags.
 func (a *Arguments) MakeLogFunc() backend.LogFunc {
 	logs := backend.DummyLogFunc()

generator/golang/option.go

@@ -55,12 +55,11 @@ type Features struct {
 	CodeRef                bool `code_ref:"Genenerate code ref by given idl-ref.yaml"`
 	KeepCodeRefName        bool `keep_code_ref_name:"Genenerate code ref but still keep file name."`
 	TrimIDL                bool `trim_idl:"Simplify IDL to the most concise form before generating code."`
-
-	JSONStringer bool `json_stringer:"Generate the JSON marshal method in String() method."`
-
-	WithFieldMask         bool `with_field_mask:"Support field-mask for generated code."`
-	FieldMaskHalfway      bool `field_mask_halfway:"Support set field-mask on not-root struct."`
-	FieldMaskZeroRequired bool `field_mask_zero_required:"Write zero value instead of current value for required fields filtered by fieldmask."`
+	EnableNestedStruct     bool `enable_nested_struct:"Generate nested field when 'thrift.nested=\"true\"' annotation is set to field, valid only in 'slim template'"`
+	JSONStringer           bool `json_stringer:"Generate the JSON marshal method in String() method."`
+	WithFieldMask          bool `with_field_mask:"Support field-mask for generated code."`
+	FieldMaskHalfway       bool `field_mask_halfway:"Support set field-mask on not-root struct."`
+	FieldMaskZeroRequired  bool `field_mask_zero_required:"Write zero value instead of current value for required fields filtered by fieldmask."`
 }
 
 var defaultFeatures = Features{
@@ -95,6 +94,7 @@ var defaultFeatures = Features{
 	WithFieldMask:          false,
 	FieldMaskHalfway:       false,
 	FieldMaskZeroRequired:  false,
+	EnableNestedStruct:     false,
 }
 
 type param struct {

generator/golang/scope.go

@@ -496,6 +496,7 @@ type Field struct {
 	setter          Name
 	isset           Name
 	deepEqual       Name
+	isNested        bool
 }
 
 // GoName returns the name in go code of the field.
@@ -555,6 +556,11 @@ func (f *Field) DeepEqual() Name {
 	return f.deepEqual
 }
 
+// IsNested returns whether the field is a nested type.
+func (f *Field) IsNested() bool {
+	return f.isNested
+}
+
 // StructLike is a wrapper for the parser.StructLike.
 type StructLike struct {
 	*parser.StructLike

generator/golang/scope_internal.go

@@ -24,8 +24,12 @@ import (
 	"github.com/cloudwego/thriftgo/pkg/namespace"
 )
 
-// A prefix to denote synthesized identifiers.
-const prefix = "$"
+const (
+	// A prefix to denote synthesized identifiers.
+	prefix = "$"
+	// nestedAnnotation is to denote the field is nested type.
+	nestedAnnotation = "thrift.nested"
+)
 
 func _p(id string) string {
 	return prefix + id
@@ -321,6 +325,15 @@ func (s *Scope) buildStructLike(cu *CodeUtils, v *parser.StructLike, usedName ..
 	// reserve method names
 	for _, f := range v.Fields {
 		fn := s.identify(cu, f.Name)
+		if cu.Features().EnableNestedStruct && isNestedField(f) {
+			// EnableNestedStruct, the type name needs to be used when retrieving the value for getter&setter
+			fn = s.identify(cu, f.Type.Name)
+			if strings.Contains(fn, ".") {
+				fns := strings.Split(fn, ".")
+				fn = s.identify(cu, fns[len(fns)-1])
+			}
+		}
+
 		st.scope.Add("Get"+fn, _p("get:"+f.Name))
 		if cu.Features().GenerateSetter {
 			st.scope.Add("Set"+fn, _p("set:"+f.Name))
@@ -339,6 +352,10 @@ func (s *Scope) buildStructLike(cu *CodeUtils, v *parser.StructLike, usedName ..
 	// field names
 	for _, f := range v.Fields {
 		fn := s.identify(cu, f.Name)
+		isNested := false
+		if cu.Features().EnableNestedStruct && isNestedField(f) {
+			isNested = true
+		}
 		fn = st.scope.Add(fn, f.Name)
 		id := id2str(f.ID)
 		st.fields = append(st.fields, &Field{
@@ -350,6 +367,7 @@ func (s *Scope) buildStructLike(cu *CodeUtils, v *parser.StructLike, usedName ..
 			setter:    Name(st.scope.Get(_p("set:" + f.Name))),
 			isset:     Name(st.scope.Get(_p("isset:" + f.Name))),
 			deepEqual: Name(st.scope.Get(_p("deepequal:" + id))),
+			isNested:  isNested,
 		})
 	}
 
@@ -401,6 +419,18 @@ func (s *Scope) resolveTypesAndValues(cu *CodeUtils) {
 	for f := range ff {
 		v := f.Field
 		f.typeName = ensureType(resolver.ResolveFieldTypeName(v))
+		// This is used to set the real field name for nested struct, ex.
+		// type T struct {
+		// 	*Nested
+		// }
+		if cu.Features().EnableNestedStruct && isNestedField(f.Field) {
+			name := f.typeName.Deref().String()
+			if strings.Contains(name, ".") {
+				names := strings.Split(name, ".")
+				name = names[len(names)-1]
+			}
+			f.name = Name(name)
+		}
 		f.frugalTypeName = ensureType(frugalResolver.ResolveFrugalTypeName(v.Type))
 		f.defaultTypeName = ensureType(resolver.GetDefaultValueTypeName(v))
 		if f.IsSetDefault() {
@@ -450,3 +480,14 @@ func (s *Scope) resolveTypesAndValues(cu *CodeUtils) {
 		}
 	}
 }
+
+func isNestedField(f *parser.Field) bool {
+	annos := f.Annotations.Get(nestedAnnotation)
+	if len(annos) == 0 {
+		return false
+	}
+	if strings.EqualFold(annos[0], "true") {
+		return true
+	}
+	return false
+}

generator/golang/templates/slim/slim.go

@@ -38,7 +38,11 @@ type {{$TypeName}} struct {
 	{{- if and Features.ReserveComments .ReservedComments}}
 	{{.ReservedComments}}
 	{{- end}}
-	{{(.GoName)}} {{.GoTypeName}} {{GenFieldTags . (InsertionPoint $.Category $.Name .Name "tag")}} 
+	{{- if .IsNested}}
+		{{.GoTypeName}} {{GenFieldTags . (InsertionPoint $.Category $.Name .Name "tag")}}
+	{{else}}
+		{{(.GoName)}} {{.GoTypeName}} {{GenFieldTags . (InsertionPoint $.Category $.Name .Name "tag")}}
+	{{- end}}
 {{- end}}
 	{{- if Features.KeepUnknownFields}}
 	{{- UseStdLibrary "unknown"}}