Add additional fields support to codegen/features

codegen/features/cmd/cmd.go

@@ -19,12 +19,18 @@ import (
 )
 
 func main() {
-	if len(os.Args) < 6 {
+	if len(os.Args) < 7 {
 		printUsage("not enough parameters")
 	}
 
 	templateFilePath := os.Args[1]
-	conf := newConfiguration(os.Args[2], os.Args[3], os.Args[4], os.Args[5])
+	fileName := os.Args[2]
+	name := os.Args[3]
+	receiver := os.Args[4]
+	featuresStr := os.Args[5]
+	additionalFieldsStr := os.Args[6]
+
+	conf := newConfiguration(fileName, name, receiver, featuresStr, additionalFieldsStr)
 
 	funcs := template.FuncMap{
 		"firstLower": func(s string) string {
@@ -45,14 +51,14 @@ func main() {
 
 	formattedOutput := lo.PanicOnErr(format.Source(buffer.Bytes()))
 
-	panicOnError(os.WriteFile(conf.FileName, formattedOutput, 0600))
+	panicOnError(os.WriteFile(fileName, formattedOutput, 0600))
 }
 
 // printUsage prints the usage of the variadic code generator in case of an error.
 func printUsage(errorMsg string) {
 	_, _ = fmt.Fprintf(os.Stderr, "Error:\t%s\n\n", errorMsg)
 	_, _ = fmt.Fprintf(os.Stderr, "Usage of gen/cmd:\n")
-	_, _ = fmt.Fprintf(os.Stderr, "\tcmd [templateFile] [outputFile] [typeName] [typeReceiver] [features separated by space]\n")
+	_, _ = fmt.Fprintf(os.Stderr, "\tcmd [templateFile] [outputFile] [typeName] [typeReceiver] [features separated by space] [additional fields separated by space (FieldName=FieldValue)]\n")
 
 	os.Exit(2)
 }

codegen/features/cmd/configuration.go

@@ -2,30 +2,68 @@ package main
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 )
 
-type configuration struct {
-	FileName string
-	Name     string
-	Receiver string
-	Features map[string]bool
-}
-
-func newConfiguration(fileName, name, receiver, featuresStr string) *configuration {
+func newConfiguration(fileName, name, receiver, featuresStr, additionalFieldsStr string) any {
+	// add all enabled features to a map
 	features := make(map[string]bool)
 	for _, feature := range strings.Split(featuresStr, " ") {
 		features[feature] = true
 	}
 
-	return &configuration{
-		FileName: fileName,
-		Name:     name,
-		Receiver: strings.ToLower(receiver),
-		Features: features,
+	additionalFields := make(map[string]string)
+	for _, additionalField := range strings.Split(additionalFieldsStr, " ") {
+		if len(additionalField) == 0 {
+			continue
+		}
+
+		values := strings.Split(additionalField, "=")
+		if len(values) != 2 {
+			panic(fmt.Sprintf("failed to parse format of additional field, should be \"FieldName=FieldValue\", got \"%s\"", additionalField))
+		}
+
+		additionalFields[values[0]] = values[1]
+	}
+
+	// create a dynamic configuration struct
+	structData := map[string]any{
+		"FileName": fileName,
+		"Name":     name,
+		"Receiver": strings.ToLower(receiver),
+		"Features": features,
+	}
+
+	// add the additional fields
+	for key, value := range additionalFields {
+		structData[key] = value
+	}
+
+	// gather all struct fields
+	structFields := make([]reflect.StructField, 0, len(structData))
+	for key, value := range structData {
+		structFields = append(structFields, reflect.StructField{
+			Name: key,
+			Type: reflect.TypeOf(value),
+		})
+	}
+
+	// create a struct type at runtime
+	structType := reflect.StructOf(structFields)
+
+	// create a new struct instance using reflection
+	newStruct := reflect.New(structType).Elem()
+
+	// set the values of the dynamic fields
+	for i := 0; i < newStruct.NumField(); i++ {
+		field := newStruct.Field(i)
+		fieldName := structType.Field(i).Name
+
+		if value, ok := structData[fieldName]; ok {
+			field.Set(reflect.ValueOf(value))
+		}
 	}
-}
 
-func (c *configuration) String() string {
-	return fmt.Sprintf("configuration{\n\tFileName:%s,\n\tName:%s,\n\tReceiver:%s,\n\tFeatures:%v,\n}\n", c.FileName, c.Name, c.Receiver, c.Features)
+	return newStruct.Interface()
 }