add validate comment

tool/protobuf/protoc-gen-bswagger/generator.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"net/http"
+	"reflect"
 	"regexp"
 	"strings"
 
@@ -184,6 +185,12 @@ func (t *swaggerGen) getQueryParameter(file *descriptor.FileDescriptorProto,
 	cleanComment := tag.GetCommentWithoutTag(fComment.Leading)
 
 	p.Description = strings.Trim(strings.Join(cleanComment, "\n"), "\n\r ")
+	validateComment := getValidateComment(field)
+	if p.Description != "" && validateComment != "" {
+		p.Description = p.Description + "," + validateComment
+	} else if validateComment != "" {
+		p.Description = validateComment
+	}
 	p.In = "query"
 	p.Required = generator.GetFieldRequired(field, t.Reg, input)
 	typ, isArray, format := getFieldSwaggerType(field)
@@ -208,6 +215,12 @@ func (t *swaggerGen) schemaForField(file *descriptor.FileDescriptorProto,
 		gen.Error(err, "comment not found err %+v")
 	}
 	schema.Description = strings.Trim(fComment.Leading, "\n\r ")
+	validateComment := getValidateComment(field)
+	if schema.Description != "" && validateComment != "" {
+		schema.Description = schema.Description + "," + validateComment
+	} else if validateComment != "" {
+		schema.Description = validateComment
+	}
 	typ, isArray, format := getFieldSwaggerType(field)
 	if !generator.IsScalar(field) {
 		if generator.IsMap(field, t.Reg) {
@@ -303,3 +316,20 @@ func getFieldSwaggerType(field *descriptor.FieldDescriptorProto) (typeName strin
 	}
 	return
 }
+
+func getValidateComment(field *descriptor.FieldDescriptorProto) string {
+	var (
+		tags []reflect.StructTag
+	)
+	comment := ""
+	//get required info from gogoproto.moretags
+	moretags := tag.GetMoreTags(field)
+	if moretags != nil {
+		tags = []reflect.StructTag{reflect.StructTag(*moretags)}
+	}
+	validateTag := tag.GetTagValue("validate", tags)
+	if len(validateTag) > 0 {
+		comment = validateTag
+	}
+	return comment
+}