add new functionality and improve backend server structure

- Enhance server functionality and optimize backend code
- Add multi-database support (PostgreSQL, MySQL, SQLite)

server/core_backend-server/plugins/jsvm/mapper.go

@@ -0,0 +1,67 @@
+package jsvm
+
+import (
+	"reflect"
+	"strings"
+	"unicode"
+
+	"github.com/dop251/goja"
+)
+
+var (
+	_ goja.FieldNameMapper = (*FieldMapper)(nil)
+)
+
+// FieldMapper provides custom mapping between Go and JavaScript property names.
+//
+// It is similar to the builtin "uncapFieldNameMapper" but also converts
+// all uppercase identifiers to their lowercase equivalent (eg. "GET" -> "get").
+type FieldMapper struct {
+}
+
+// FieldName implements the [FieldNameMapper.FieldName] interface method.
+func (u FieldMapper) FieldName(_ reflect.Type, f reflect.StructField) string {
+	return convertGoToJSName(f.Name)
+}
+
+// MethodName implements the [FieldNameMapper.MethodName] interface method.
+func (u FieldMapper) MethodName(_ reflect.Type, m reflect.Method) string {
+	return convertGoToJSName(m.Name)
+}
+
+var nameExceptions = map[string]string{"OAuth2": "oauth2"}
+
+func convertGoToJSName(name string) string {
+	if v, ok := nameExceptions[name]; ok {
+		return v
+	}
+
+	startUppercase := make([]rune, 0, len(name))
+
+	for _, c := range name {
+		if c != '_' && !unicode.IsUpper(c) && !unicode.IsDigit(c) {
+			break
+		}
+
+		startUppercase = append(startUppercase, c)
+	}
+
+	totalStartUppercase := len(startUppercase)
+
+	// all uppercase eg. "JSON" -> "json"
+	if len(name) == totalStartUppercase {
+		return strings.ToLower(name)
+	}
+
+	// eg. "JSONField" -> "jsonField"
+	if totalStartUppercase > 1 {
+		return strings.ToLower(name[0:totalStartUppercase-1]) + name[totalStartUppercase-1:]
+	}
+
+	// eg. "GetField" -> "getField"
+	if totalStartUppercase == 1 {
+		return strings.ToLower(name[0:1]) + name[1:]
+	}
+
+	return name
+}