add go_struct_tags as a field

README.md

@@ -46,4 +46,5 @@ go_type = 1001
 go_import = 1002
 go_import_alias = 1003
 go_zero_override = 1004
+go_struct_tags = 1005
 Because `protoc` can't process the extended options, so we can't find the by name, just by place.

cmd/protoc-gen-go/internal_gengo/main.go

@@ -12,6 +12,7 @@ import (
 	"go/token"
 	"math"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 	"unicode"
@@ -40,6 +41,7 @@ type overrideParams struct {
 	goImport       string
 	goImportAlias  string
 	goZeroOverride string
+	goStructTags   string
 }
 
 // overrideFields stores all the found messages which are created to override types
@@ -52,6 +54,8 @@ var SupportedFeatures = uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPT
 var GenerateProtobufSpecific = true
 var TypeOverride = false
 
+var tagRegex = regexp.MustCompile(`([^=;]+)=([^;]+);?`)
+
 var lookupExtensionNames = []string{"go_type", "go_import", "go_import_alias"}
 
 // Standard library dependencies.
@@ -202,6 +206,9 @@ func processExtensions(field *protogen.Field) (overrideParams, bool) {
 			log.Log("processExtensions:: zero override found!")
 			override.goZeroOverride = ex.Value().String()
 			ok = true
+		case impl.FieldOptionGoStructTags:
+			override.goStructTags = ex.Value().String()
+			ok = true
 		}
 	}
 	return override, ok
@@ -227,6 +234,9 @@ func processUninterpretedOptions(field *protogen.Field) (overrideParams, bool) {
 				case impl.FieldOptionGoZeroOverride:
 					override.goZeroOverride = string(o.GetStringValue())
 					ok = true
+				case impl.FieldOptionGoStructTags:
+					override.goStructTags = string(o.GetStringValue())
+					ok = true
 				}
 			}
 		}
@@ -531,13 +541,14 @@ func genMessageField(g *protogen.GeneratedFile, f *fileInfo, m *messageInfo, fie
 	if pointer {
 		goType = "*" + goType
 	}
-	if overrideParam, ok := goTypeOverride(m.GoIdent.GoName, field.GoName); ok {
+	if overrideParam, ok := getOverrideField(m.GoIdent.GoName, field.GoName); ok {
 		goType = overrideParam.goType
 	}
 	tags := structTags{
 		{"protobuf", fieldProtobufTagValue(field)},
-		{"json", fieldJSONTagValue(field)},
 	}
+	tags = append(tags, getAdditionalTags(m, field)...)
+
 	if field.Desc.IsMap() {
 		key := field.Message.Fields[0]
 		val := field.Message.Fields[1]
@@ -563,6 +574,41 @@ func genMessageField(g *protogen.GeneratedFile, f *fileInfo, m *messageInfo, fie
 	sf.append(field.GoName)
 }
 
+func getOverrideField(messageName, fieldName string) (overrideParams, bool) {
+	if !TypeOverride {
+		return overrideParams{}, false
+	}
+	overrideMsg, ok := overrideFields[messageName]
+	if !ok {
+		return overrideParams{}, false
+	}
+	overrideField, ok := overrideMsg[fieldName]
+	return overrideField, ok
+}
+
+func getAdditionalTags(m *messageInfo, field *protogen.Field) [][2]string {
+	o, ok := getOverrideField(m.GoIdent.GoName, field.GoName)
+	if !ok || o.goStructTags == "" {
+		return [][2]string{
+			{"json", fieldJSONTagValue(field)},
+		}
+	}
+	return buildTags(o.goStructTags)
+}
+
+func buildTags(wrappedTags string) [][2]string {
+	var tags [][2]string
+	for _, token := range strings.Split(wrappedTags, ";") {
+		for _, submatch := range tagRegex.FindAllStringSubmatch(token, -1) {
+			if len(submatch) != 3 {
+				continue
+			}
+			tags = append(tags, [2]string{submatch[1], submatch[2]})
+		}
+	}
+	return tags
+}
+
 // genMessageDefaultDecls generates consts and vars holding the default
 // values of fields.
 func genMessageDefaultDecls(g *protogen.GeneratedFile, f *fileInfo, m *messageInfo) {
@@ -573,7 +619,7 @@ func genMessageDefaultDecls(g *protogen.GeneratedFile, f *fileInfo, m *messageIn
 		}
 		name := "Default_" + m.GoIdent.GoName + "_" + field.GoName
 		goType, _ := fieldGoType(g, f, field)
-		if overrideParam, ok := goTypeOverride(m.GoIdent.GoName, field.GoName); ok {
+		if overrideParam, ok := getOverrideField(m.GoIdent.GoName, field.GoName); ok {
 			goType = overrideParam.goType
 		}
 		defVal := field.Desc.Default()
@@ -698,7 +744,7 @@ func genMessageGetterMethods(g *protogen.GeneratedFile, f *fileInfo, m *messageI
 
 		// Getter for message field.
 		goType, pointer := fieldGoType(g, f, field)
-		overrideParam, overwritten := goTypeOverride(m.GoIdent.GoName, field.GoName)
+		overrideParam, overwritten := getOverrideField(m.GoIdent.GoName, field.GoName)
 		if overwritten {
 			goType = overrideParam.goType
 		}
@@ -1068,18 +1114,3 @@ func (c trailingComment) String() string {
 	}
 	return s
 }
-
-func goTypeOverride(msgName string, fieldName string) (overrideParams, bool) {
-	if TypeOverride {
-		// TODO check the case when goType is a map
-		if oMsg, okMsg := overrideFields[msgName]; okMsg {
-			if o, okField := oMsg[fieldName]; okField {
-				return o, true
-			}
-		}
-		// if strings.Contains(goType, "RepeatedString") {
-		// 	return strings.ReplaceAll(goType, "RepeatedString", "[]string")
-		// }
-	}
-	return overrideParams{}, false
-}

cmd/protoc-gen-go/internal_gengo/main_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"testing"
 
+	"github.com/infiniteloopcloud/protoc-gen-go-types/compiler/protogen"
 	"github.com/infiniteloopcloud/protoc-gen-go-types/parser"
 )
 
@@ -30,3 +31,64 @@ func TestGenerateFile(t *testing.T) {
 		}
 	}
 }
+
+func TestBuildTags(t *testing.T) {
+	tags := buildTags("json=something,omitempty;validate=date")
+	if len(tags) != 2 {
+		t.Fatal("invalid tag count, must be 2")
+	}
+	if tags[0][0] != "json" {
+		t.Errorf("Invalid tag name, should be 'json', instead of %q", tags[0][0])
+	}
+	if tags[0][1] != "something,omitempty" {
+		t.Errorf("Invalid tag name, should be 'something,omitempty', instead of %q", tags[0][1])
+	}
+	if tags[1][0] != "validate" {
+		t.Errorf("Invalid tag name, should be 'validate', instead of %q", tags[1][0])
+	}
+	if tags[1][1] != "date" {
+		t.Errorf("Invalid tag name, should be 'date', instead of %q", tags[1][1])
+	}
+}
+
+func TestGetAdditionalTags(t *testing.T) {
+	TypeOverride = true
+	overrideFields = map[string]map[string]overrideParams{
+		"TestStruct": {
+			"TestField": overrideParams{
+				goStructTags: `json=id_dont_know,omitempty;boil=donno;validate=true`,
+			},
+		},
+	}
+	tags := getAdditionalTags(&messageInfo{
+		Message: &protogen.Message{
+			GoIdent: protogen.GoIdent{
+				GoName: "TestStruct",
+			},
+		},
+	}, &protogen.Field{
+		GoName: "TestField",
+	})
+
+	if len(tags) != 3 {
+		t.Fatal("Tags length must be 3")
+	}
+	if tags[0][0] != "json" {
+		t.Errorf("First tag should be `json`, instead of %s", tags[0][0])
+	}
+	if tags[0][1] != "id_dont_know,omitempty" {
+		t.Errorf("First tag should be `id_dont_know,omitempty`, instead of %s", tags[0][1])
+	}
+	if tags[1][0] != "boil" {
+		t.Errorf("First tag should be `boil`, instead of %s", tags[1][0])
+	}
+	if tags[1][1] != "donno" {
+		t.Errorf("First tag should be `donno`, instead of %s", tags[1][1])
+	}
+	if tags[2][0] != "validate" {
+		t.Errorf("First tag should be `validate`, instead of %s", tags[2][0])
+	}
+	if tags[2][1] != "true" {
+		t.Errorf("First tag should be `true`, instead of %s", tags[2][1])
+	}
+}

cmd/protoc-gen-go/internal_gengo/test_data/config.proto

@@ -11,4 +11,5 @@ extend google.protobuf.FieldOptions {
   optional string go_import = 1002;
   optional string go_import_alias = 1003;
   optional string go_zero_override = 1004;
+  optional string go_struct_tags = 1005;
 }

cmd/protoc-gen-go/internal_gengo/test_data/test.proto

@@ -27,7 +27,7 @@ message Test {
   map<uint64, RepeatedString> map_field = 2 [(go_type) = "map[uint64][]string", (go_import) = ""];
   string test = 3;
   string optStr = 4 [(go_type) = "null.String", (go_import) = "github.com/volatiletech/null/v9", (go_import_alias) = "null"];
-  int32 optInt = 5 [(go_type) = "null.Int32"];
+  int32 optInt = 5 [(go_type) = "null.Int32", (go_struct_tags) = "json=-;boil=hello"];
   int32 optBigInt = 6 [(go_type) = "null.Int64", (go_import) = "github.com/volatiletech/null/v9", (go_import_alias) = "null"];
   string something = 7 [(go_type) = "Something", (go_import) = "", (go_zero_override) = "\"\""];
 }

internal/impl/decode.go

@@ -24,11 +24,13 @@ const (
 	FieldOptionGoImport       = "go_import"
 	FieldOptionGoImportAlias  = "go_import_alias"
 	FieldOptionGoZeroOverride = "go_zero_override"
+	FieldOptionGoStructTags   = "go_struct_tags"
 
 	FieldOptionGoTypeNum         = 1001
 	FieldOptionGoImportNum       = 1002
 	FieldOptionGoImportAliasNum  = 1003
 	FieldOptionGoZeroOverrideNum = 1004
+	FieldOptionGoStructTagsNum   = 1005
 )
 
 var errDecode = errors.New("cannot parse invalid wire-format data")
@@ -285,6 +287,8 @@ func (mi *MessageInfo) fallbackCreateExtension(num protowire.Number) (protorefle
 		name = FieldOptionGoImportAlias
 	case FieldOptionGoZeroOverrideNum:
 		name = FieldOptionGoZeroOverride
+	case FieldOptionGoStructTagsNum:
+		name = FieldOptionGoStructTags
 	default:
 		return nil, errors.New("invalid name")
 	}