Add JsonSerializable.createPerFieldToJson (google#1230)

rrousselGit · web-flow · commit f37664af948d · 2022-11-03T07:19:34.000-07:00
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
@@ -24,5 +24,7 @@ dev_dependencies:
   test: ^1.16.0
 
 dependency_overrides:
+  json_annotation:
+    path: ../json_annotation
   json_serializable:
     path: ../json_serializable
diff --git a/json_annotation/CHANGELOG.md b/json_annotation/CHANGELOG.md
@@ -1,3 +1,9 @@
+## 4.8.0-dev
+
+- Require Dart SDK `>=2.18.0`.
+- Added `JsonSerializable.createPerFieldToJson` which allows generating
+  a `_$ModelPerFieldToJson`, enabling partial encoding of a model.
+
 ## 4.7.1-dev
 
 - Update `JsonKey` documentation to align with new features in 
diff --git a/json_annotation/lib/src/json_serializable.dart b/json_annotation/lib/src/json_serializable.dart
@@ -87,6 +87,13 @@ class JsonSerializable {
   /// such as [fieldRename].
   final bool? createFieldMap;
 
+  /// If `true` (defaults to false), a private, static `_$ExamplePerFieldToJson`
+  /// abstract class will be geenrated in the part file.
+  ///
+  /// This abstract class will contain one static function per property,
+  /// exposing a way to encode only this property instead of the entire object.
+  final bool? createPerFieldToJson;
+
   /// If `true` (the default), A top-level function is created that you can
   /// reference from your class.
   ///
@@ -249,6 +256,7 @@ class JsonSerializable {
     this.includeIfNull,
     this.converters,
     this.genericArgumentFactories,
+    this.createPerFieldToJson,
   });
 
   factory JsonSerializable.fromJson(Map<String, dynamic> json) =>
diff --git a/json_annotation/lib/src/json_serializable.g.dart b/json_annotation/lib/src/json_serializable.g.dart
diff --git a/json_annotation/pubspec.yaml b/json_annotation/pubspec.yaml
@@ -1,5 +1,5 @@
 name: json_annotation
-version: 4.7.1-dev
+version: 4.8.0-dev
 description: >-
   Classes and helper functions that support JSON code generation via the
   `json_serializable` package.
diff --git a/json_serializable/CHANGELOG.md b/json_serializable/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 - Require Dart SDK `>=2.18.0`.
 - Require `analyzer: ^5.2.0`
+- Require `json_annotation: '>=4.8.0 <4.9.0'`
 
 ## 6.5.4
 
diff --git a/json_serializable/README.md b/json_serializable/README.md
@@ -279,6 +279,7 @@ targets:
           constructor: ""
           create_factory: true
           create_field_map: false
+          create_per_field_to_json: false
           create_to_json: true
           disallow_unrecognized_keys: false
           explicit_to_json: false
@@ -299,15 +300,15 @@ targets:
 [`Enum`]: https://api.dart.dev/stable/dart-core/Enum-class.html
 [`int`]: https://api.dart.dev/stable/dart-core/int-class.html
 [`Iterable`]: https://api.dart.dev/stable/dart-core/Iterable-class.html
-[`JsonConverter`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonConverter-class.html
-[`JsonEnum.valueField`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonEnum/valueField.html
-[`JsonEnum`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonEnum-class.html
-[`JsonKey.fromJson`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonKey/fromJson.html
-[`JsonKey.toJson`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonKey/toJson.html
-[`JsonKey`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonKey-class.html
-[`JsonLiteral`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonLiteral-class.html
-[`JsonSerializable`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonSerializable-class.html
-[`JsonValue`]: https://pub.dev/documentation/json_annotation/4.7.0/json_annotation/JsonValue-class.html
+[`JsonConverter`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonConverter-class.html
+[`JsonEnum.valueField`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonEnum/valueField.html
+[`JsonEnum`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonEnum-class.html
+[`JsonKey.fromJson`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonKey/fromJson.html
+[`JsonKey.toJson`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonKey/toJson.html
+[`JsonKey`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonKey-class.html
+[`JsonLiteral`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonLiteral-class.html
+[`JsonSerializable`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonSerializable-class.html
+[`JsonValue`]: https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonValue-class.html
 [`List`]: https://api.dart.dev/stable/dart-core/List-class.html
 [`Map`]: https://api.dart.dev/stable/dart-core/Map-class.html
 [`num`]: https://api.dart.dev/stable/dart-core/num-class.html
diff --git a/json_serializable/lib/src/check_dependencies.dart b/json_serializable/lib/src/check_dependencies.dart
@@ -10,7 +10,7 @@ import 'package:pubspec_parse/pubspec_parse.dart';
 
 const _productionDirectories = {'lib', 'bin'};
 const _annotationPkgName = 'json_annotation';
-final requiredJsonAnnotationMinVersion = Version.parse('4.7.0');
+final requiredJsonAnnotationMinVersion = Version.parse('4.8.0-dev');
 
 Future<void> pubspecHasRightVersion(BuildStep buildStep) async {
   final segments = buildStep.inputId.pathSegments;
diff --git a/json_serializable/lib/src/decode_helper.dart b/json_serializable/lib/src/decode_helper.dart
@@ -31,7 +31,7 @@ abstract class DecodeHelper implements HelperCore {
 
     final mapType = config.anyMap ? 'Map' : 'Map<String, dynamic>';
     buffer.write('$targetClassReference '
-        '${prefix}FromJson${genericClassArgumentsImpl(true)}'
+        '${prefix}FromJson${genericClassArgumentsImpl(withConstraints: true)}'
         '($mapType json');
 
     if (config.genericArgumentFactories) {
diff --git a/json_serializable/lib/src/encoder_helper.dart b/json_serializable/lib/src/encoder_helper.dart
@@ -16,6 +16,32 @@ import 'unsupported_type_error.dart';
 abstract class EncodeHelper implements HelperCore {
   String _fieldAccess(FieldElement field) => '$_toJsonParamName.${field.name}';
 
+  String createPerFieldToJson(Set<FieldElement> accessibleFieldSet) {
+    final buffer = StringBuffer()
+      ..writeln('// ignore: unused_element')
+      ..writeln('abstract class _\$${element.name.nonPrivate}PerFieldToJson {');
+
+    for (final field in accessibleFieldSet) {
+      buffer
+        ..writeln('  // ignore: unused_element')
+        ..write(
+          'static Object? ${field.name}'
+          '${genericClassArgumentsImpl(withConstraints: true)}'
+          '(${field.type} $_toJsonParamName',
+        );
+
+      if (config.genericArgumentFactories) {
+        _writeGenericArgumentFactories(buffer);
+      }
+
+      buffer.writeln(') => ${_serializeField(field, _toJsonParamName)};');
+    }
+
+    buffer.writeln('}');
+
+    return buffer.toString();
+  }
+
   /// Generates an object containing metadatas related to the encoding,
   /// destined to be used by other code-generators.
   String createFieldMap(Set<FieldElement> accessibleFieldSet) {
@@ -42,26 +68,19 @@ abstract class EncodeHelper implements HelperCore {
 
     final buffer = StringBuffer();
 
-    final functionName = '${prefix}ToJson${genericClassArgumentsImpl(true)}';
+    final functionName =
+        '${prefix}ToJson${genericClassArgumentsImpl(withConstraints: true)}';
     buffer.write('Map<String, dynamic> '
         '$functionName($targetClassReference $_toJsonParamName');
 
-    if (config.genericArgumentFactories) {
-      for (var arg in element.typeParameters) {
-        final helperName = toJsonForType(
-          arg.instantiate(nullabilitySuffix: NullabilitySuffix.none),
-        );
-        buffer.write(',Object? Function(${arg.name} value) $helperName');
-      }
-      if (element.typeParameters.isNotEmpty) {
-        buffer.write(',');
-      }
-    }
+    if (config.genericArgumentFactories) _writeGenericArgumentFactories(buffer);
+
     buffer.write(') ');
 
-    final writeNaive = accessibleFields.every(_writeJsonValueNaive);
+    final canWriteAllJsonValuesWithoutNullCheck =
+        accessibleFields.every(_canWriteJsonWithoutNullCheck);
 
-    if (writeNaive) {
+    if (canWriteAllJsonValuesWithoutNullCheck) {
       // write simple `toJson` method that includes all keys...
       _writeToJsonSimple(buffer, accessibleFields);
     } else {
@@ -72,6 +91,18 @@ abstract class EncodeHelper implements HelperCore {
     yield buffer.toString();
   }
 
+  void _writeGenericArgumentFactories(StringBuffer buffer) {
+    for (var arg in element.typeParameters) {
+      final helperName = toJsonForType(
+        arg.instantiate(nullabilitySuffix: NullabilitySuffix.none),
+      );
+      buffer.write(',Object? Function(${arg.name} value) $helperName');
+    }
+    if (element.typeParameters.isNotEmpty) {
+      buffer.write(',');
+    }
+  }
+
   void _writeToJsonSimple(StringBuffer buffer, Iterable<FieldElement> fields) {
     buffer
       ..writeln('=> <String, dynamic>{')
@@ -112,7 +143,7 @@ abstract class EncodeHelper implements HelperCore {
       }
 
       final expression = _serializeField(field, safeFieldAccess);
-      if (_writeJsonValueNaive(field)) {
+      if (_canWriteJsonWithoutNullCheck(field)) {
         if (directWrite) {
           buffer.writeln('      $safeJsonKeyString: $expression,');
         } else {
@@ -160,7 +191,7 @@ abstract class EncodeHelper implements HelperCore {
 
   /// Returns `true` if the field can be written to JSON 'naively' – meaning
   /// we can avoid checking for `null`.
-  bool _writeJsonValueNaive(FieldElement field) {
+  bool _canWriteJsonWithoutNullCheck(FieldElement field) {
     final jsonKey = jsonKeyFor(field);
 
     if (jsonKey.includeIfNull) {
diff --git a/json_serializable/lib/src/generator_helper.dart b/json_serializable/lib/src/generator_helper.dart
@@ -112,6 +112,10 @@ class GeneratorHelper extends HelperCore with EncodeHelper, DecodeHelper {
       yield createFieldMap(accessibleFieldSet);
     }
 
+    if (config.createPerFieldToJson) {
+      yield createPerFieldToJson(accessibleFieldSet);
+    }
+
     if (config.createToJson) {
       yield* createToJson(accessibleFieldSet);
     }
diff --git a/json_serializable/lib/src/helper_core.dart b/json_serializable/lib/src/helper_core.dart
@@ -28,7 +28,7 @@ abstract class HelperCore {
 
   @protected
   String get targetClassReference =>
-      '${element.name}${genericClassArgumentsImpl(false)}';
+      '${element.name}${genericClassArgumentsImpl(withConstraints: false)}';
 
   @protected
   String nameAccess(FieldElement field) => jsonKeyFor(field).name;
@@ -45,7 +45,7 @@ abstract class HelperCore {
   ///
   /// Returns the output of calling [genericClassArguments] with [element].
   @protected
-  String genericClassArgumentsImpl(bool withConstraints) =>
+  String genericClassArgumentsImpl({required bool withConstraints}) =>
       genericClassArguments(element, withConstraints);
 
   @protected
diff --git a/json_serializable/lib/src/type_helpers/config_types.dart b/json_serializable/lib/src/type_helpers/config_types.dart
@@ -46,6 +46,7 @@ class ClassConfig {
   final bool createFactory;
   final bool createToJson;
   final bool createFieldMap;
+  final bool createPerFieldToJson;
   final bool disallowUnrecognizedKeys;
   final bool explicitToJson;
   final FieldRename fieldRename;
@@ -62,6 +63,7 @@ class ClassConfig {
     required this.createFactory,
     required this.createToJson,
     required this.createFieldMap,
+    required this.createPerFieldToJson,
     required this.disallowUnrecognizedKeys,
     required this.explicitToJson,
     required this.fieldRename,
@@ -80,6 +82,8 @@ class ClassConfig {
         constructor: config.constructor ?? ClassConfig.defaults.constructor,
         createFieldMap:
             config.createFieldMap ?? ClassConfig.defaults.createFieldMap,
+        createPerFieldToJson: config.createPerFieldToJson ??
+            ClassConfig.defaults.createPerFieldToJson,
         createFactory:
             config.createFactory ?? ClassConfig.defaults.createFactory,
         createToJson: config.createToJson ?? ClassConfig.defaults.createToJson,
@@ -106,6 +110,7 @@ class ClassConfig {
     createFactory: true,
     createToJson: true,
     createFieldMap: false,
+    createPerFieldToJson: false,
     disallowUnrecognizedKeys: false,
     explicitToJson: false,
     fieldRename: FieldRename.none,
@@ -121,6 +126,7 @@ class ClassConfig {
         createFactory: createFactory,
         createToJson: createToJson,
         createFieldMap: createFieldMap,
+        createPerFieldToJson: createPerFieldToJson,
         ignoreUnannotated: ignoreUnannotated,
         explicitToJson: explicitToJson,
         includeIfNull: includeIfNull,
diff --git a/json_serializable/lib/src/utils.dart b/json_serializable/lib/src/utils.dart
@@ -57,6 +57,8 @@ JsonSerializable _valueForAnnotation(ConstantReader reader) => JsonSerializable(
       createFactory: reader.read('createFactory').literalValue as bool?,
       createToJson: reader.read('createToJson').literalValue as bool?,
       createFieldMap: reader.read('createFieldMap').literalValue as bool?,
+      createPerFieldToJson:
+          reader.read('createPerFieldToJson').literalValue as bool?,
       disallowUnrecognizedKeys:
           reader.read('disallowUnrecognizedKeys').literalValue as bool?,
       explicitToJson: reader.read('explicitToJson').literalValue as bool?,
@@ -103,6 +105,8 @@ ClassConfig mergeConfig(
     createFactory: annotation.createFactory ?? config.createFactory,
     createToJson: annotation.createToJson ?? config.createToJson,
     createFieldMap: annotation.createFieldMap ?? config.createFieldMap,
+    createPerFieldToJson:
+        annotation.createPerFieldToJson ?? config.createPerFieldToJson,
     disallowUnrecognizedKeys:
         annotation.disallowUnrecognizedKeys ?? config.disallowUnrecognizedKeys,
     explicitToJson: annotation.explicitToJson ?? config.explicitToJson,
diff --git a/json_serializable/pubspec.yaml b/json_serializable/pubspec.yaml
@@ -1,5 +1,5 @@
 name: json_serializable
-version: 6.5.5-dev
+version: 6.6.0-dev
 description: >-
   Automatically generate code for converting to and from JSON by annotating
   Dart classes.
@@ -16,7 +16,7 @@ dependencies:
 
   # Use a tight version constraint to ensure that a constraint on
   # `json_annotation` properly constrains all features it provides.
-  json_annotation: '>=4.7.0 <4.8.0'
+  json_annotation: '>=4.8.0-dev <4.9.0'
   meta: ^1.3.0
   path: ^1.8.0
   pub_semver: ^2.0.0
@@ -37,3 +37,7 @@ dev_dependencies:
   test_descriptor: ^2.0.0
   test_process: ^2.0.0
   yaml: ^3.0.0
+
+dependency_overrides:
+  json_annotation:
+    path: ../json_annotation
diff --git a/json_serializable/test/config_test.dart b/json_serializable/test/config_test.dart
@@ -157,6 +157,7 @@ const _invalidConfig = {
   'constructor': 42,
   'create_factory': 42,
   'create_field_map': 42,
+  'create_per_field_to_json': 42,
   'create_to_json': 42,
   'disallow_unrecognized_keys': 42,
   'explicit_to_json': 42,
diff --git a/json_serializable/test/integration/create_per_field_to_json_example.dart b/json_serializable/test/integration/create_per_field_to_json_example.dart
diff --git a/json_serializable/test/integration/create_per_field_to_json_example.g.dart b/json_serializable/test/integration/create_per_field_to_json_example.g.dart
diff --git a/json_serializable/test/integration/integration_test.dart b/json_serializable/test/integration/integration_test.dart
diff --git a/json_serializable/test/shared_config.dart b/json_serializable/test/shared_config.dart
diff --git a/json_serializable/test/test_sources/test_sources.dart b/json_serializable/test/test_sources/test_sources.dart
diff --git a/json_serializable/tool/readme/readme_template.md b/json_serializable/tool/readme/readme_template.md
