feat: protoc-gen-go-errors add comment (#1961)

cmd/protoc-gen-go-errors/errors.go

@@ -82,11 +82,19 @@ func genErrorsReason(gen *protogen.Plugin, file *protogen.File, g *protogen.Gene
 		if enumCode == 0 {
 			continue
 		}
+
+		comment := v.Comments.Leading.String()
+		if comment == "" {
+			comment = v.Comments.Trailing.String()
+		}
+
 		err := &errorInfo{
 			Name:       string(enum.Desc.Name()),
 			Value:      string(v.Desc.Name()),
 			CamelValue: case2Camel(string(v.Desc.Name())),
 			HTTPCode:   enumCode,
+			Comment:    comment,
+			HasComment: len(comment) > 0,
 		}
 		ew.Errors = append(ew.Errors, err)
 	}
@@ -94,6 +102,7 @@ func genErrorsReason(gen *protogen.Plugin, file *protogen.File, g *protogen.Gene
 		return true
 	}
 	g.P(ew.execute())
+
 	return false
 }
 

cmd/protoc-gen-go-errors/template.go

@@ -8,6 +8,7 @@ import (
 var errorsTemplate = `
 {{ range .Errors }}
 
+{{if .HasComment}}{{.Comment}}{{end}}
 func Is{{.CamelValue}}(err error) bool {
 	if err == nil {
 		return false
@@ -16,6 +17,7 @@ func Is{{.CamelValue}}(err error) bool {
 	return e.Reason == {{.Name}}_{{.Value}}.String() && e.Code == {{.HTTPCode}} 
 }
 
+{{if .HasComment}}{{.Comment}}{{end}}
 func Error{{.CamelValue}}(format string, args ...interface{}) *errors.Error {
 	 return errors.New({{.HTTPCode}}, {{.Name}}_{{.Value}}.String(), fmt.Sprintf(format, args...))
 }
@@ -28,6 +30,8 @@ type errorInfo struct {
 	Value      string
 	HTTPCode   int
 	CamelValue string
+	Comment    string
+	HasComment bool
 }
 
 type errorWrapper struct {