Add support for checked

json_annotation/CHANGELOG.md

@@ -1,3 +1,12 @@
+## 0.2.5
+
+* Added `CheckedFromJsonException` which is thrown by code generated when
+ `checked` is enabled in `json_serializable`.
+
+* Also added functions to support the `checked` generation option. These
+  functions start with `$` are referenced by generated code. They are not meant
+  for direct use.
+
 ## 0.2.4
 
 * Added `fromJson` and `toJson` fields to `JsonKey` class.

json_annotation/lib/json_annotation.dart

@@ -9,6 +9,7 @@
 /// `json_serializable` when generating wrappers.
 library json_annotation;
 
+export 'src/checked_helpers.dart';
 export 'src/json_literal.dart';
 export 'src/json_serializable.dart';
 export 'src/wrapper_helpers.dart';

json_annotation/lib/src/checked_helpers.dart

@@ -0,0 +1,58 @@
+// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Helper function used in generated code when
+/// `JsonSerializableGenerator.checked` is `true`.
+///
+/// Should not be used directly.
+T $checkedNew<T>(String className, Map map, Map<String, String> fieldKeyMap,
+    T constructor()) {
+  try {
+    return constructor();
+  } on CheckedFromJsonException catch (e) {
+    e._className ??= className;
+    rethrow;
+  } catch (error, stack) {
+    throw new CheckedFromJsonException._(error, stack, map,
+        (error is ArgumentError) ? fieldKeyMap[error.name] : null, T,
+        className: className);
+  }
+}
+
+/// Helper function used in generated code when
+/// `JsonSerializableGenerator.checked` is `true`.
+///
+/// Should not be used directly.
+T $checkedConvert<T>(Map map, String key, T castFunc()) {
+  try {
+    return castFunc();
+  } on CheckedFromJsonException {
+    rethrow;
+  } catch (error, stack) {
+    throw new CheckedFromJsonException._(error, stack, map, key, T);
+  }
+}
+
+/// Exception thrown if there is a runtime exception in `fromJson`
+/// code generated when `JsonSerializableGenerator.checked` is `true`
+class CheckedFromJsonException implements Exception {
+  final Object innerError;
+  final StackTrace innerStack;
+  final String key;
+  final Map map;
+  final Type targetType;
+  final Object message;
+
+  String _className;
+  String get className => _className;
+
+  CheckedFromJsonException._(
+      this.innerError, this.innerStack, this.map, this.key, this.targetType,
+      {String className})
+      : _className = className,
+        message = _getMessage(innerError);
+
+  static Object _getMessage(Object error) =>
+      (error is ArgumentError) ? error.message : null;
+}

json_annotation/lib/src/wrapper_helpers.dart

@@ -4,7 +4,7 @@
 
 import 'dart:collection';
 
-/// Helper classes used in generated code when
+/// Helper class used in generated code when
 /// `JsonSerializableGenerator.useWrappers` is `true`.
 ///
 /// Should not be used directly.

json_serializable/CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 0.5.4
 
+* Add `checked` configuration option. If `true`, generated `fromJson` functions
+  include extra checks to validate proper deserialization of types.
+
 * Use `Map.map` for more map conversions. Simplifies generated code and fixes
   a subtle issue when the `Map` key type is `dynamic` or `Object`.
 

json_serializable/lib/builder.dart

@@ -28,6 +28,7 @@ Builder jsonSerializable(BuilderOptions options) {
   var builder = jsonPartBuilder(
       header: optionsMap.remove('header') as String,
       useWrappers: optionsMap.remove('use_wrappers') as bool,
+      checked: optionsMap.remove('checked') as bool,
       anyMap: optionsMap.remove('any_map') as bool);
 
   if (optionsMap.isNotEmpty) {

json_serializable/lib/json_serializable.dart

@@ -2,5 +2,5 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-export 'src/json_literal_generator.dart';
+export 'src/json_literal_generator.dart' show JsonLiteralGenerator;
 export 'src/json_serializable_generator.dart' show JsonSerializableGenerator;

json_serializable/lib/src/generator_helper.dart

@@ -11,6 +11,7 @@ import 'package:source_gen/source_gen.dart';
 
 import 'constants.dart';
 import 'json_key_helpers.dart';
+import 'json_literal_generator.dart';
 import 'json_serializable_generator.dart';
 import 'type_helper.dart';
 import 'type_helper_context.dart';
@@ -126,16 +127,15 @@ class _GeneratorHelper {
       var mapType = _generator.anyMap ? 'Map' : 'Map<String, dynamic>';
 
       _buffer.writeln();
-      _buffer.writeln('${_element.name} '
-          '${_prefix}FromJson($mapType json) =>');
 
       String deserializeFun(String paramOrFieldName,
               {ParameterElement ctorParam}) =>
           _deserializeForField(accessibleFields[paramOrFieldName],
               ctorParam: ctorParam);
 
+      var tempBuffer = new StringBuffer();
       var fieldsSetByFactory = writeConstructorInvocation(
-          _buffer,
+          tempBuffer,
           _element,
           accessibleFields.keys,
           accessibleFields.values
@@ -144,6 +144,21 @@ class _GeneratorHelper {
               .toList(),
           unavailableReasons,
           deserializeFun);
+
+      if (_generator.checked) {
+        var keyFieldMap = new Map<String, String>.fromIterable(
+            fieldsSetByFactory,
+            value: (k) => _nameAccess(accessibleFields[k]));
+        var mapLiteral = jsonMapAsDart(keyFieldMap, true);
+        var classLiteral = escapeDartString(_element.displayName);
+
+        _buffer.writeln(
+            '${_element.displayName} ${_prefix}FromJson($mapType json) =>'
+            '\$checkedNew($classLiteral, json, $mapLiteral, ()=>$tempBuffer)');
+      } else {
+        _buffer.writeln('${_element.name} '
+            '${_prefix}FromJson($mapType json) => $tempBuffer');
+      }
       _buffer.writeln(';');
 
       // If there are fields that are final – that are not set via the generated
@@ -297,7 +312,12 @@ void $toJsonMapHelperName(String key, dynamic value) {
     var targetType = ctorParam?.type ?? field.type;
 
     try {
-      return _getHelperContext(field).deserialize(targetType, 'json[$jsonKey]');
+      var value =
+          _getHelperContext(field).deserialize(targetType, 'json[$jsonKey]');
+      if (_generator.checked) {
+        return '\$checkedConvert(json, $jsonKey, () => $value)';
+      }
+      return value;
     } on UnsupportedTypeError catch (e) {
       throw _createInvalidGenerationError('fromJson', field, e);
     }

json_serializable/lib/src/json_literal_generator.dart

@@ -56,13 +56,13 @@ String _jsonLiteralAsDart(dynamic value, bool asConst) {
     return '${asConst ? 'const' : ''}[$listItems]';
   }
 
-  if (value is Map<String, dynamic>) return _jsonMapAsDart(value, asConst);
+  if (value is Map<String, dynamic>) return jsonMapAsDart(value, asConst);
 
   throw new StateError(
       'Should never get here – with ${value.runtimeType} - `$value`.');
 }
 
-String _jsonMapAsDart(Map<String, dynamic> value, bool asConst) {
+String jsonMapAsDart(Map<String, dynamic> value, bool asConst) {
   var buffer = new StringBuffer();
   if (asConst) {
     buffer.write('const ');

json_serializable/lib/src/json_part_builder.dart

@@ -15,11 +15,16 @@ import 'json_serializable_generator.dart';
 /// If `null`, the content of [defaultFileHeader] is used.
 /// If [header] is an empty `String` no header is added.
 ///
-/// For details on [useWrappers] and [anyMap], see [JsonSerializableGenerator].
+/// For details on [useWrappers], [anyMap], and [checked] see
+/// [JsonSerializableGenerator].
 Builder jsonPartBuilder(
-    {String header, bool useWrappers: false, bool anyMap: false}) {
+    {String header,
+    bool useWrappers: false,
+    bool anyMap: false,
+    bool checked: false}) {
   return new PartBuilder([
-    new JsonSerializableGenerator(useWrappers: useWrappers, anyMap: anyMap),
+    new JsonSerializableGenerator(
+        useWrappers: useWrappers, anyMap: anyMap, checked: checked),
     const JsonLiteralGenerator()
   ], header: header);
 }

json_serializable/lib/src/json_serializable_generator.dart

@@ -43,28 +43,41 @@ class JsonSerializableGenerator
       ].followedBy(_typeHelpers).followedBy(_coreHelpers);
 
   /// If `true`, wrappers are used to minimize the number of
-  /// [Map] and [List] instances created during serialization. This will
-  /// increase the code size, but it may improve runtime performance, especially
-  /// for large object graphs.
+  /// [Map] and [List] instances created during serialization.
+  ///
+  /// This will increase the code size, but it may improve runtime performance,
+  /// especially for large object graphs.
   final bool useWrappers;
 
-  /// If `true`, [Map] types are not assumed to be
-  /// [Map<String, dynamic>] – the default for JSON support in `dart:convert`.
-  /// This results in more code being generated, but allows [Map] types returned
+  /// If `true`, [Map] types are *not* assumed to be [Map<String, dynamic>]
+  /// – which is the default type of [Map] instances return by JSON decode in
+  /// `dart:convert`.
+  ///
+  /// This will increase the code size, but allows [Map] types returned
   /// from other sources, such as `package:yaml`.
+  ///
   /// *Note: in many cases the key values are still assumed to be [String]*.
   final bool anyMap;
 
+  /// If `true`, generated `fromJson` functions include extra checks to validate
+  /// proper deserialization of types.
+  ///
+  /// If an exception is thrown during deserialization, a
+  /// [CheckedFromJsonException] is thrown.
+  final bool checked;
+
   /// Creates an instance of [JsonSerializableGenerator].
   ///
   /// If [typeHelpers] is not provided, two built-in helpers are used:
   /// [JsonHelper] and [DateTimeHelper].
-  const JsonSerializableGenerator(
-      {List<TypeHelper> typeHelpers,
-      bool useWrappers: false,
-      bool anyMap: false})
-      : this.useWrappers = useWrappers ?? false,
+  const JsonSerializableGenerator({
+    List<TypeHelper> typeHelpers,
+    bool useWrappers: false,
+    bool anyMap: false,
+    bool checked: false,
+  })  : this.useWrappers = useWrappers ?? false,
         this.anyMap = anyMap ?? false,
+        this.checked = checked ?? false,
         this._typeHelpers = typeHelpers ?? _defaultHelpers;
 
   /// Creates an instance of [JsonSerializableGenerator].

json_serializable/pubspec.yaml

@@ -24,3 +24,7 @@ dev_dependencies:
   logging: ^0.11.3+1
   test: ^0.12.3
   yaml: ^2.1.13
+
+dependency_overrides:
+  json_annotation:
+    path: ../json_annotation

json_serializable/test/config/angular_comp.yaml

@@ -0,0 +1,9 @@
+builders:
+  scss_builder:
+    target: "scss_builder"
+    import: "package:angular_components/builder.dart"
+    builder_factories: ["scssBuilder"]
+    build_to: cache
+    build_extensions:
+      .scss: [".scss.css"]
+      .sass: [".scss.css"]

json_serializable/test/config/angular_config.yaml

@@ -0,0 +1,21 @@
+builders:
+  angular:
+    import: "package:angular/builder.dart"
+    builder_factories:
+      - templatePlaceholder
+      - templateCompiler
+      - stylesheetCompiler
+    auto_apply: none
+    applies_builders:
+      - "angular|placeholder_cleanup"
+      - "angular|component_source_cleanup"
+    # See https://github.com/dart-lang/angular/issues/988.
+    is_optional: true
+    required_inputs:
+      - ".css"
+    build_extensions:
+      .css:
+        - ".css.dart"
+        - ".css.shim.dart"
+      .dart:
+        - ".template.dart"