Migrate implementation of json_serializable to null-safety (#841)

Fixes #821

Author: kevmoo

json_annotation/CHANGELOG.md

@@ -1,7 +1,8 @@
-## 4.0.1-dev
+## 4.0.1
 
 - Fix a potential error with `checked: true` when `ArgumentError.message` is 
   `null`.
+- Updated `JsonSerializable.fromJson` to handle `null` values.
 
 ## 4.0.0
 

json_annotation/lib/src/json_serializable.g.dart

@@ -1,5 +1,5 @@
 name: json_annotation
-version: 4.0.1-dev
+version: 4.0.1
 description: >-
   Classes and helper functions that support JSON code generation via the
   `json_serializable` package.
@@ -10,4 +10,4 @@ environment:
 # When changing JsonSerializable class.
 # dev_dependencies:
 #   build_runner: ^1.0.0
-#   json_serializable: ^3.1.0
+#   json_serializable: ^4.0.0

json_annotation/pubspec.yaml

@@ -1,3 +1,7 @@
+## 5.0.0-dev
+
+- Implementation is now null-safe.
+
 ## 4.0.3
 
 - Correctly handle nullable values with `genericArgumentFactories`.

json_serializable/CHANGELOG.md

@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.12
-
 import 'package:json_annotation/json_annotation.dart';
 
 part 'example.g.dart';

json_serializable/example/example.dart

@@ -34,7 +34,7 @@ Builder jsonSerializable(BuilderOptions options) {
       lines.add('There is a problem with "${e.key}".');
     }
     if (e.message != null) {
-      lines.add(e.message);
+      lines.add(e.message!);
     } else if (e.innerError != null) {
       lines.add(e.innerError.toString());
     }

json_serializable/example/example.g.dart

@@ -25,15 +25,15 @@ abstract class DecodeHelper implements HelperCore {
     Map<String, FieldElement> accessibleFields,
     Map<String, String> unavailableReasons,
   ) {
-    assert(config.createFactory);
+    assert(config.createFactory!);
     final buffer = StringBuffer();
 
-    final mapType = config.anyMap ? 'Map' : 'Map<String, dynamic>';
+    final mapType = config.anyMap! ? 'Map' : 'Map<String, dynamic>';
     buffer.write('$targetClassReference '
         '${prefix}FromJson${genericClassArgumentsImpl(true)}'
         '($mapType json');
 
-    if (config.genericArgumentFactories) {
+    if (config.genericArgumentFactories!) {
       for (var arg in element.typeParameters) {
         final helperName = fromJsonForType(
           arg.instantiate(nullabilitySuffix: NullabilitySuffix.none),
@@ -49,8 +49,8 @@ abstract class DecodeHelper implements HelperCore {
     buffer.write(') {\n');
 
     String deserializeFun(String paramOrFieldName,
-            {ParameterElement ctorParam}) =>
-        _deserializeForField(accessibleFields[paramOrFieldName],
+            {ParameterElement? ctorParam}) =>
+        _deserializeForField(accessibleFields[paramOrFieldName]!,
             ctorParam: ctorParam);
 
     final data = _writeConstructorInvocation(
@@ -72,7 +72,7 @@ abstract class DecodeHelper implements HelperCore {
     final checks = _checkKeys(accessibleFields.values
         .where((fe) => data.usedCtorParamsAndFields.contains(fe.name)));
 
-    if (config.checked) {
+    if (config.checked!) {
       final classLiteral = escapeDartString(element.name);
 
       buffer..write('''
@@ -84,12 +84,12 @@ abstract class DecodeHelper implements HelperCore {
 
       for (final field in data.fieldsToSet) {
         buffer.writeln();
-        final safeName = safeNameAccess(accessibleFields[field]);
+        final safeName = safeNameAccess(accessibleFields[field]!);
         buffer
           ..write('''
     \$checkedConvert(json, $safeName, (v) => ''')
           ..write('val.$field = ')
-          ..write(_deserializeForField(accessibleFields[field],
+          ..write(_deserializeForField(accessibleFields[field]!,
               checkedProperty: true))
           ..write(');');
       }
@@ -98,7 +98,7 @@ abstract class DecodeHelper implements HelperCore {
   }''');
 
       final fieldKeyMap = Map.fromEntries(data.usedCtorParamsAndFields
-          .map((k) => MapEntry(k, nameAccess(accessibleFields[k])))
+          .map((k) => MapEntry(k, nameAccess(accessibleFields[k]!)))
           .where((me) => me.key != me.value));
 
       String fieldKeyMapArg;
@@ -131,22 +131,22 @@ abstract class DecodeHelper implements HelperCore {
     String constantList(Iterable<FieldElement> things) =>
         'const ${jsonLiteralAsDart(things.map(nameAccess).toList())}';
 
-    if (config.disallowUnrecognizedKeys) {
+    if (config.disallowUnrecognizedKeys!) {
       final allowKeysLiteral = constantList(accessibleFields);
 
       args.add('allowedKeys: $allowKeysLiteral');
     }
 
     final requiredKeys =
-        accessibleFields.where((fe) => jsonKeyFor(fe).required).toList();
+        accessibleFields.where((fe) => jsonKeyFor(fe).required!).toList();
     if (requiredKeys.isNotEmpty) {
       final requiredKeyLiteral = constantList(requiredKeys);
 
       args.add('requiredKeys: $requiredKeyLiteral');
     }
 
     final disallowNullKeys = accessibleFields
-        .where((fe) => jsonKeyFor(fe).disallowNullValue)
+        .where((fe) => jsonKeyFor(fe).disallowNullValue!)
         .toList();
     if (disallowNullKeys.isNotEmpty) {
       final disallowNullKeyLiteral = constantList(disallowNullKeys);
@@ -163,18 +163,17 @@ abstract class DecodeHelper implements HelperCore {
 
   String _deserializeForField(
     FieldElement field, {
-    ParameterElement ctorParam,
-    bool checkedProperty,
+    ParameterElement? ctorParam,
+    bool checkedProperty = false,
   }) {
-    checkedProperty ??= false;
     final jsonKeyName = safeNameAccess(field);
     final targetType = ctorParam?.type ?? field.type;
     final contextHelper = getHelperContext(field);
     final defaultProvided = jsonKeyFor(field).defaultValue != null;
 
     String value;
     try {
-      if (config.checked) {
+      if (config.checked!) {
         value = contextHelper
             .deserialize(
               targetType,
@@ -205,7 +204,7 @@ abstract class DecodeHelper implements HelperCore {
     final jsonKey = jsonKeyFor(field);
     final defaultValue = jsonKey.defaultValue;
     if (defaultValue != null) {
-      if (jsonKey.disallowNullValue && jsonKey.required) {
+      if (jsonKey.disallowNullValue! && jsonKey.required!) {
         log.warning('The `defaultValue` on field `${field.name}` will have no '
             'effect because both `disallowNullValue` and `required` are set to '
             '`true`.');

json_serializable/lib/builder.dart

@@ -17,15 +17,15 @@ abstract class EncodeHelper implements HelperCore {
   String _fieldAccess(FieldElement field) => '$_toJsonParamName.${field.name}';
 
   Iterable<String> createToJson(Set<FieldElement> accessibleFields) sync* {
-    assert(config.createToJson);
+    assert(config.createToJson!);
 
     final buffer = StringBuffer();
 
     final functionName = '${prefix}ToJson${genericClassArgumentsImpl(true)}';
     buffer.write('Map<String, dynamic> '
         '$functionName($targetClassReference $_toJsonParamName');
 
-    if (config.genericArgumentFactories) {
+    if (config.genericArgumentFactories!) {
       for (var arg in element.typeParameters) {
         final helperName = toJsonForType(
           arg.instantiate(nullabilitySuffix: NullabilitySuffix.none),
@@ -140,7 +140,7 @@ abstract class EncodeHelper implements HelperCore {
   bool _writeJsonValueNaive(FieldElement field) {
     final jsonKey = jsonKeyFor(field);
 
-    return jsonKey.includeIfNull ||
+    return jsonKey.includeIfNull! ||
         (!field.type.isNullableType && !_fieldHasCustomEncoder(field));
   }
 

json_serializable/lib/src/decode_helper.dart

@@ -17,9 +17,9 @@ class _FieldSet implements Comparable<_FieldSet> {
   _FieldSet._(this.field, this.sortField)
       : assert(field.name == sortField.name);
 
-  factory _FieldSet(FieldElement classField, FieldElement superField) {
+  factory _FieldSet(FieldElement? classField, FieldElement? superField) {
     // At least one of these will != null, perhaps both.
-    final fields = [classField, superField].where((fe) => fe != null).toList();
+    final fields = [classField, superField].whereType<FieldElement>().toList();
 
     // Prefer the class field over the inherited field when sorting.
     final sortField = fields.first;
@@ -58,9 +58,9 @@ class _FieldSet implements Comparable<_FieldSet> {
     /// Returns the offset of given field/property in its source file – with a
     /// preference for the getter if it's defined.
     int _offsetFor(FieldElement e) {
-      if (e.getter != null && e.getter.nameOffset != e.nameOffset) {
+      if (e.getter != null && e.getter!.nameOffset != e.nameOffset) {
         assert(e.nameOffset == -1);
-        return e.getter.nameOffset;
+        return e.getter!.nameOffset;
       }
       return e.nameOffset;
     }