Add enum_field_rename option in build.yaml for default enum value renaming

json_annotation/lib/src/json_serializable.dart

@@ -8,6 +8,7 @@ import 'allowed_keys_helpers.dart';
 import 'checked_helpers.dart';
 import 'enum_helpers.dart';
 import 'json_converter.dart';
+import 'json_enum.dart' show JsonEnum;
 import 'json_key.dart';
 
 part 'json_serializable.g.dart';
@@ -175,6 +176,12 @@ class JsonSerializable {
   /// fields annotated with [JsonKey].
   final FieldRename? fieldRename;
 
+  /// Default field rename for enum values when not set on [JsonEnum].
+  ///
+  /// Only applies when configured via `build.yaml`; has no effect when set on
+  /// [JsonSerializable] annotations in source code.
+  final FieldRename? enumFieldRename;
+
   /// When `true` on classes with type parameters (generic types), extra
   /// "helper" parameters will be generated for `fromJson` and/or `toJson` to
   /// support serializing values of those types.
@@ -285,6 +292,7 @@ class JsonSerializable {
     this.disallowUnrecognizedKeys,
     this.explicitToJson,
     this.fieldRename,
+    this.enumFieldRename,
     this.ignoreUnannotated,
     this.includeIfNull,
     this.converters,
@@ -308,6 +316,7 @@ class JsonSerializable {
     disallowUnrecognizedKeys: false,
     explicitToJson: false,
     fieldRename: FieldRename.none,
+    enumFieldRename: FieldRename.none,
     ignoreUnannotated: false,
     includeIfNull: true,
     genericArgumentFactories: false,
@@ -329,6 +338,7 @@ class JsonSerializable {
         disallowUnrecognizedKeys ?? defaults.disallowUnrecognizedKeys,
     explicitToJson: explicitToJson ?? defaults.explicitToJson,
     fieldRename: fieldRename ?? defaults.fieldRename,
+    enumFieldRename: enumFieldRename ?? defaults.enumFieldRename,
     ignoreUnannotated: ignoreUnannotated ?? defaults.ignoreUnannotated,
     includeIfNull: includeIfNull ?? defaults.includeIfNull,
     genericArgumentFactories:

json_serializable/README.md

@@ -322,6 +322,7 @@ targets:
           date_time_utc: false
           disallow_unrecognized_keys: false
           explicit_to_json: false
+          enum_field_rename: none
           field_rename: none
           generic_argument_factories: false
           ignore_unannotated: false

json_serializable/lib/src/encoder_helper.dart

@@ -174,7 +174,10 @@ mixin EncodeHelper implements HelperCore {
     // We can consider enums as kinda like having custom converters
     // same rules apply. If `null` is in the set of encoded values, we
     // should not write naive
-    final enumWithNullValue = enumFieldWithNullInEncodeMap(field.type);
+    final enumWithNullValue = enumFieldWithNullInEncodeMap(
+      field.type,
+      defaultEnumFieldRename: config.enumFieldRename,
+    );
     if (enumWithNullValue != null) {
       return !enumWithNullValue;
     }

json_serializable/lib/src/enum_utils.dart

@@ -5,6 +5,7 @@
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:build/build.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:source_gen/source_gen.dart';
 import 'package:source_helper/source_helper.dart';
@@ -19,8 +20,14 @@ String constMapName(DartType targetType) =>
 ///
 /// Otherwise, returns `true` if [targetType] is nullable OR if one of the
 /// encoded values of the enum is `null`.
-bool? enumFieldWithNullInEncodeMap(DartType targetType) {
-  final enumMap = _enumMap(targetType);
+bool? enumFieldWithNullInEncodeMap(
+  DartType targetType, {
+  FieldRename? defaultEnumFieldRename,
+}) {
+  final enumMap = _enumMap(
+    targetType,
+    defaultEnumFieldRename: defaultEnumFieldRename,
+  );
 
   if (enumMap == null) return null;
 
@@ -34,10 +41,12 @@ bool? enumFieldWithNullInEncodeMap(DartType targetType) {
 String? enumValueMapFromType(
   DartType targetType, {
   bool nullWithNoAnnotation = false,
+  FieldRename? defaultEnumFieldRename,
 }) {
   final enumMap = _enumMap(
     targetType,
     nullWithNoAnnotation: nullWithNoAnnotation,
+    defaultEnumFieldRename: defaultEnumFieldRename,
   );
 
   if (enumMap == null) return null;
@@ -56,6 +65,7 @@ String? enumValueMapFromType(
 Map<FieldElement, Object?>? _enumMap(
   DartType targetType, {
   bool nullWithNoAnnotation = false,
+  FieldRename? defaultEnumFieldRename,
 }) {
   final targetTypeElement = targetType.element;
   if (targetTypeElement == null) return null;
@@ -68,12 +78,20 @@ Map<FieldElement, Object?>? _enumMap(
     return null;
   }
 
+  if (jsonEnum.valueField != null && jsonEnum.fieldRename != FieldRename.none) {
+    log.warning(
+      '`JsonEnum.fieldRename` is ignored when `valueField` is set. '
+      'Enum values are derived from the `${jsonEnum.valueField}` field.',
+    );
+  }
+
   return {
     for (var field in enumFields)
       field: _generateEntry(
         field: field,
         jsonEnum: jsonEnum,
         targetType: targetType,
+        defaultEnumFieldRename: defaultEnumFieldRename,
       ),
   };
 }
@@ -82,6 +100,7 @@ Object? _generateEntry({
   required FieldElement field,
   required JsonEnum jsonEnum,
   required DartType targetType,
+  FieldRename? defaultEnumFieldRename,
 }) {
   final annotation = const TypeChecker.typeNamed(
     JsonValue,
@@ -91,8 +110,6 @@ Object? _generateEntry({
   if (annotation == null) {
     final valueField = jsonEnum.valueField;
     if (valueField != null) {
-      // TODO: fieldRename is pointless here!!! At least log a warning!
-
       final fieldElementType = field.type.element as EnumElement;
 
       final e = fieldElementType.getField(valueField);
@@ -125,7 +142,10 @@ Object? _generateEntry({
         );
       }
     } else {
-      return encodedFieldName(jsonEnum.fieldRename, field.name!);
+      final effectiveRename = jsonEnum.fieldRename != FieldRename.none
+          ? jsonEnum.fieldRename
+          : (defaultEnumFieldRename ?? FieldRename.none);
+      return encodedFieldName(effectiveRename, field.name!);
     }
   } else {
     final reader = ConstantReader(annotation);

json_serializable/lib/src/json_enum_generator.dart

@@ -8,9 +8,12 @@ import 'package:json_annotation/json_annotation.dart';
 import 'package:source_gen/source_gen.dart';
 
 import 'enum_utils.dart';
+import 'settings.dart';
 
 class JsonEnumGenerator extends GeneratorForAnnotation<JsonEnum> {
-  const JsonEnumGenerator() : super(inPackage: 'json_annotation');
+  JsonEnumGenerator(this._settings) : super(inPackage: 'json_annotation');
+
+  final Settings _settings;
 
   @override
   List<String> generateForAnnotatedElement(
@@ -28,6 +31,7 @@ class JsonEnumGenerator extends GeneratorForAnnotation<JsonEnum> {
     final value = enumValueMapFromType(
       element.thisType,
       nullWithNoAnnotation: true,
+      defaultEnumFieldRename: _settings.config.enumFieldRename,
     );
 
     return [?value];

json_serializable/lib/src/json_part_builder.dart

@@ -29,7 +29,7 @@ Builder jsonPartBuilder({
     [
       _UnifiedGenerator([
         JsonSerializableGenerator.fromSettings(settings),
-        const JsonEnumGenerator(),
+        JsonEnumGenerator(settings),
       ]),
       const JsonLiteralGenerator(),
     ],

json_serializable/lib/src/settings.dart

@@ -52,7 +52,7 @@ class Settings {
   /// If [typeHelpers] is not provided, the built-in helpers are used:
   /// [BigIntHelper], [DateTimeHelper], [DurationHelper], [JsonHelper], and
   /// [UriHelper].
-  Settings({required JsonSerializable? config, List<TypeHelper>? typeHelpers})
+  Settings({JsonSerializable? config, List<TypeHelper>? typeHelpers})
     : config = config != null
           ? ClassConfig.fromJsonSerializable(config)
           : ClassConfig.defaults,

json_serializable/lib/src/type_helpers/config_types.dart

@@ -65,6 +65,7 @@ class ClassConfig {
   final bool disallowUnrecognizedKeys;
   final bool explicitToJson;
   final FieldRename fieldRename;
+  final FieldRename enumFieldRename;
   final bool genericArgumentFactories;
   final bool ignoreUnannotated;
   final bool includeIfNull;
@@ -85,6 +86,7 @@ class ClassConfig {
     required this.disallowUnrecognizedKeys,
     required this.explicitToJson,
     required this.fieldRename,
+    required this.enumFieldRename,
     required this.genericArgumentFactories,
     required this.ignoreUnannotated,
     required this.includeIfNull,
@@ -121,6 +123,8 @@ class ClassConfig {
             config.genericArgumentFactories ??
             ClassConfig.defaults.genericArgumentFactories,
         fieldRename: config.fieldRename ?? ClassConfig.defaults.fieldRename,
+        enumFieldRename:
+            config.enumFieldRename ?? ClassConfig.defaults.enumFieldRename,
         disallowUnrecognizedKeys:
             config.disallowUnrecognizedKeys ??
             ClassConfig.defaults.disallowUnrecognizedKeys,
@@ -142,6 +146,7 @@ class ClassConfig {
     disallowUnrecognizedKeys: false,
     explicitToJson: false,
     fieldRename: FieldRename.none,
+    enumFieldRename: FieldRename.none,
     genericArgumentFactories: false,
     ignoreUnannotated: false,
     includeIfNull: true,
@@ -162,6 +167,7 @@ class ClassConfig {
     includeIfNull: includeIfNull,
     genericArgumentFactories: genericArgumentFactories,
     fieldRename: fieldRename,
+    enumFieldRename: enumFieldRename,
     disallowUnrecognizedKeys: disallowUnrecognizedKeys,
     dateTimeUtc: dateTimeUtc,
     // TODO typeConverters = []

json_serializable/lib/src/type_helpers/enum_helper.dart

@@ -21,7 +21,10 @@ class EnumHelper extends TypeHelper<TypeHelperContextWithConfig> {
     String expression,
     TypeHelperContextWithConfig context,
   ) {
-    final memberContent = enumValueMapFromType(targetType);
+    final memberContent = enumValueMapFromType(
+      targetType,
+      defaultEnumFieldRename: context.config.enumFieldRename,
+    );
 
     if (memberContent == null) {
       return null;
@@ -30,7 +33,11 @@ class EnumHelper extends TypeHelper<TypeHelperContextWithConfig> {
     context.addMember(memberContent);
 
     if (targetType.isNullableType ||
-        enumFieldWithNullInEncodeMap(targetType) == true) {
+        enumFieldWithNullInEncodeMap(
+              targetType,
+              defaultEnumFieldRename: context.config.enumFieldRename,
+            ) ==
+            true) {
       return '${constMapName(targetType)}[$expression]';
     } else {
       return '${constMapName(targetType)}[$expression]!';
@@ -44,7 +51,10 @@ class EnumHelper extends TypeHelper<TypeHelperContextWithConfig> {
     TypeHelperContextWithConfig context,
     bool defaultProvided,
   ) {
-    final memberContent = enumValueMapFromType(targetType);
+    final memberContent = enumValueMapFromType(
+      targetType,
+      defaultEnumFieldRename: context.config.enumFieldRename,
+    );
 
     if (memberContent == null) {
       return null;

json_serializable/lib/src/utils.dart

@@ -71,6 +71,7 @@ JsonSerializable _valueForAnnotation(ConstantReader reader) => JsonSerializable(
       reader.read('disallowUnrecognizedKeys').literalValue as bool?,
   explicitToJson: reader.read('explicitToJson').literalValue as bool?,
   fieldRename: readEnum(reader.read('fieldRename'), FieldRename.values),
+  enumFieldRename: readEnum(reader.read('enumFieldRename'), FieldRename.values),
   genericArgumentFactories:
       reader.read('genericArgumentFactories').literalValue as bool?,
   ignoreUnannotated: reader.read('ignoreUnannotated').literalValue as bool?,
@@ -121,6 +122,7 @@ ClassConfig mergeConfig(
         annotation.disallowUnrecognizedKeys ?? config.disallowUnrecognizedKeys,
     explicitToJson: annotation.explicitToJson ?? config.explicitToJson,
     fieldRename: annotation.fieldRename ?? config.fieldRename,
+    enumFieldRename: annotation.enumFieldRename ?? config.enumFieldRename,
     genericArgumentFactories:
         annotation.genericArgumentFactories ??
         (classElement.typeParameters.isNotEmpty &&

json_serializable/test/config_test.dart

@@ -136,6 +136,9 @@ void main() {
 
         String lastLine;
         lastLine = switch (entry.key) {
+          'enum_field_rename' =>
+            '`42` is not one of the supported values: none, kebab, snake, '
+                'pascal, screamingSnake',
           'field_rename' =>
             '`42` is not one of the supported values: none, kebab, snake, '
                 'pascal, screamingSnake',
@@ -178,6 +181,7 @@ const _invalidConfig = {
   'create_to_json': 42,
   'date_time_utc': 42,
   'disallow_unrecognized_keys': 42,
+  'enum_field_rename': 42,
   'explicit_to_json': 42,
   'field_rename': 42,
   'generic_argument_factories': 42,