feat: support new generate flag generate_json_str (#120)

generator/golang/imports.go

@@ -87,6 +87,7 @@ func (im *importManager) init(cu *CodeUtils, ast *parser.Thrift) {
 		"unknown":           DefaultUnknownLib,
 		"meta":              DefaultMetaLib,
 		"thrift_reflection": ThriftReflectionLib,
+		"json_utils":        ThriftJSONUtilLib,
 		"fieldmask":         ThriftFieldMaskLib,
 	}
 	for pkg, path := range std {

generator/golang/option.go

@@ -55,7 +55,9 @@ 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."`
-	WithFieldMask          bool `with_field_mask:"Support field-mask for generated code."`
+
+	JSONStringer  bool `json_stringer:"Generate the JSON marshal method in String() method."`
+	WithFieldMask bool `with_field_mask:"Support field-mask for generated code."`
 }
 
 var defaultFeatures = Features{
@@ -86,6 +88,7 @@ var defaultFeatures = Features{
 	GenerateReflectionInfo: false,
 	EnumAsINT32:            false,
 	TrimIDL:                false,
+	JSONStringer:           false,
 	WithFieldMask:          false,
 }
 

generator/golang/templates/slim/slim.go

@@ -92,11 +92,17 @@ func (p *{{$TypeName}}) CarryingUnknownFields() bool {
 {{template "FieldIsSet" .}}
 
 func (p *{{$TypeName}}) String() string {
+	{{- if Features.JSONStringer}}
+	{{- UseStdLibrary "json_utils"}}
+	JsonBytes , _  := json_utils.JSONFunc(p)
+	return string(JsonBytes)	
+	{{- else}}
 	if p == nil {
 		return "<nil>"
 	}
 	{{- UseStdLibrary "fmt"}}
 	return fmt.Sprintf("{{$TypeName}}(%+v)", *p)
+	{{- end}}
 }
 
 {{- if eq .Category "exception"}}

generator/golang/templates/struct.go

@@ -107,11 +107,18 @@ var fieldIDToName_{{$TypeName}} = map[int16]string{
 {{template "StructLikeWriteField" .}}
 
 func (p *{{$TypeName}}) String() string {
+	{{- if Features.JSONStringer}}
+	{{- UseStdLibrary "json_utils"}}
+		JsonBytes , _  := json_utils.JSONFunc(p)
+		return string(JsonBytes)
+	{{- else}}
 	if p == nil {
 		return "<nil>"
 	}
 	{{- UseStdLibrary "fmt"}}
 	return fmt.Sprintf("{{$TypeName}}(%+v)", *p)
+	{{- end}}
+
 }
 
 {{- if eq .Category "exception"}}

generator/golang/util.go

@@ -46,6 +46,7 @@ const (
 	ThriftFieldMaskLib  = "github.com/cloudwego/thriftgo/fieldmask"
 	ThriftOptionLib     = "github.com/cloudwego/thriftgo/option"
 	defaultTemplate     = "default"
+	ThriftJSONUtilLib   = "github.com/cloudwego/thriftgo/utils/json_utils"
 )
 
 var escape = regexp.MustCompile(`\\.`)

test/golang/cases_and_options/run_test.sh

@@ -44,6 +44,7 @@ features=(\
     nil_safe \
     frugal_tag \
     unescape_double_quote \
+    json_stringer \ 
 )
 
 run_cases() {

utils/json_utils/json_utils.go

@@ -0,0 +1,29 @@
+// Copyright 2023 CloudWeGo Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package json_utils
+
+import "encoding/json"
+
+// jsonMarshaler customize json.Marshal as you like
+type jsonMarshaler func(v interface{}) ([]byte, error)
+
+var JSONFunc jsonMarshaler = json.Marshal
+
+// ResetJSONMarshalFunc replace the JSON marshal func
+// to all code which are generated by thriftgo.
+// Usually, it is used in String() method.
+func ResetJSONMarshalFunc(jn jsonMarshaler) {
+	JSONFunc = jn
+}