Cleanup inference to enable clean DDC compile

CHANGELOG.md

@@ -1,7 +1,12 @@
-## 0.1.1
+## 0.2.0
 
-* Fail generation when undefined types are encountered.
-  Throw a helpful error.
+* **BREAKING** Fail generation for types that are not a JSON primitive or that
+  do not explicitly supports JSON serialization. 
+
+* Eliminated all implicit casts in generated code. These would end up being
+  runtime checks in most cases.
+
+* Provide a helpful error when generation fails due to undefined types.
 
 ## 0.1.0+1
 
@@ -10,7 +15,11 @@
 ## 0.1.0
 
 * Split off from [source_gen](https://pub.dartlang.org/packages/source_gen).
+
 * Add `/* unsafe */` comments to generated output likely to be unsafe.
+
 * Support (de)serializing values in `Map`.
+
 * Fix ordering of fields when they are initialized via constructor.
+
 * Don't use static members when calculating fields to (de)serialize.

analysis_options.yaml

@@ -1,5 +1,6 @@
 analyzer:
-  strong-mode: true
+  strong-mode:
+    implicit-casts: false
   errors:
     unused_element: error
     unused_import: error

example/example.dart

@@ -17,7 +17,7 @@ class Person extends Object with _$PersonSerializerMixin {
 
   Person(this.firstName, this.lastName, {this.middleName, this.dateOfBirth});
 
-  factory Person.fromJson(json) => _$PersonFromJson(json);
+  factory Person.fromJson(Map<String, dynamic> json) => _$PersonFromJson(json);
 }
 
 @JsonSerializable()
@@ -29,7 +29,7 @@ class Order extends Object with _$OrderSerializerMixin {
 
   Order();
 
-  factory Order.fromJson(json) => _$OrderFromJson(json);
+  factory Order.fromJson(Map<String, dynamic> json) => _$OrderFromJson(json);
 }
 
 @JsonSerializable(createToJson: false)
@@ -40,7 +40,7 @@ class Item {
 
   Item();
 
-  factory Item.fromJson(json) => _$ItemFromJson(json);
+  factory Item.fromJson(Map<String, dynamic> json) => _$ItemFromJson(json);
 }
 
 @JsonLiteral('data.json')

lib/src/json_serializable_generator.dart

@@ -76,7 +76,7 @@ class JsonSerializableGenerator
     // Explicitly using `LinkedHashMap` – we want these ordered.
     var fields = new LinkedHashMap<String, FieldElement>.fromIterable(
         fieldsList,
-        key: (f) => f.name);
+        key: (FieldElement f) => f.name);
 
     // Get the constructor to use for the factory
 
@@ -111,8 +111,14 @@ class JsonSerializableGenerator
 
       var pairs = <String>[];
       fields.forEach((fieldName, field) {
-        pairs.add("'${_fieldToJsonMapKey(fieldName, field)}': "
-            "${_fieldToJsonMapValue(fieldName, field.type)}");
+        try {
+          pairs.add("'${_fieldToJsonMapKey(fieldName, field)}': "
+              "${_fieldToJsonMapValue(fieldName, field.type)}");
+        } on _UnsupportedTypeError {
+          throw new InvalidGenerationSourceError(
+              "Could not generate `toJson` code for `${friendlyNameForElement(field)}`.",
+              todo: "Make sure all of the types are serializable.");
+        }
       });
       buffer.writeln(pairs.join(','));
 
@@ -188,7 +194,8 @@ class JsonSerializableGenerator
     // Generate the static factory method
     //
     buffer.writeln();
-    buffer.writeln('$className ${prefix}FromJson(Map json) =>');
+    buffer
+        .writeln('$className ${prefix}FromJson(Map<String, dynamic> json) =>');
     buffer.write('    new $className(');
     buffer.writeAll(
         ctorArguments.map((paramElement) => _jsonMapAccessToField(
@@ -245,20 +252,20 @@ class JsonSerializableGenerator
       return _mapFieldToJsonMapValue(expression, fieldType, depth);
     }
 
-    return "$expression /* unsafe */";
+    throw new _UnsupportedTypeError(fieldType, expression);
   }
 
   String _listFieldToJsonMapValue(
       String expression, DartType fieldType, int depth) {
-    assert(_coreListChecker.isAssignableFromType(fieldType));
+    assert(_coreIterableChecker.isAssignableFromType(fieldType));
 
     // This block will yield a regular list, which works fine for JSON
     // Although it's possible that child elements may be marked unsafe
 
     var isList = _coreListChecker.isAssignableFromType(fieldType);
     var substitute = "v$depth";
-    var subFieldValue = _fieldToJsonMapValue(substitute,
-        _getIterableGenericType(fieldType as InterfaceType), depth + 1);
+    var subFieldValue = _fieldToJsonMapValue(
+        substitute, _getIterableGenericType(fieldType), depth + 1);
 
     // In the case of trivial JSON types (int, String, etc), `subFieldValue`
     // will be identical to `substitute` – so no explicit mapping is needed.
@@ -313,7 +320,7 @@ class JsonSerializableGenerator
           "$expression.keys,"
           "$expression.values.map(($substitute) => $subFieldValue))";
     }
-    return "$expression /* unsafe */";
+    throw new _UnsupportedTypeError(fieldType, expression);
   }
 
   String _jsonMapAccessToField(String name, FieldElement field,
@@ -322,7 +329,14 @@ class JsonSerializableGenerator
     var result = "json['$name']";
 
     var targetType = ctorParam?.type ?? field.type;
-    return _writeAccessToJsonValue(result, targetType);
+
+    try {
+      return _writeAccessToJsonValue(result, targetType);
+    } on _UnsupportedTypeError {
+      throw new InvalidGenerationSourceError(
+          "Could not generate fromJson code for `${friendlyNameForElement(field)}`.",
+          todo: "Make sure all of the types are serializable.");
+    }
   }
 
   String _writeAccessToJsonValue(String varExpression, DartType searchType,
@@ -335,16 +349,15 @@ class JsonSerializableGenerator
     }
 
     if (_coreIterableChecker.isAssignableFromType(searchType)) {
-      var iterableGenericType =
-          _getIterableGenericType(searchType as InterfaceType);
+      var iterableGenericType = _getIterableGenericType(searchType);
 
       var itemVal = "v$depth";
       var itemSubVal = _writeAccessToJsonValue(itemVal, iterableGenericType,
           depth: depth + 1);
 
       // If `itemSubVal` is the same, then we don't need to do anything fancy
       if (itemVal == itemSubVal) {
-        return varExpression;
+        return '$varExpression as List';
       }
 
       var output = "($varExpression as List)?.map(($itemVal) => $itemSubVal)";
@@ -370,7 +383,7 @@ class JsonSerializableGenerator
           _coreStringChecker.isExactlyType(keyArg);
 
       if (!safeKey) {
-        return "$varExpression /* unsafe key type */";
+        throw new _UnsupportedTypeError(keyArg, varExpression);
       }
 
       // this is the trivial case. Do a runtime cast to the known type of JSON
@@ -379,15 +392,22 @@ class JsonSerializableGenerator
         return "$varExpression as Map<String, dynamic>";
       }
 
+      if (_stringBoolNumChecker.isAssignableFromType(valueArg)) {
+        // No mapping of the values is required!
+        return "$varExpression == null ? null :"
+            "new Map<String, $valueArg>.from($varExpression as Map)";
+      }
+
+      // In this case, we're going to create a new Map with matching reified
+      // types.
+
       var itemVal = "v$depth";
       var itemSubVal =
           _writeAccessToJsonValue(itemVal, valueArg, depth: depth + 1);
 
-      // In this case, we're going to create a new Map with matching reified
-      // types.
       return "$varExpression == null ? null :"
           "new Map<String, $valueArg>.fromIterables("
-          "($varExpression as Map).keys,"
+          "($varExpression as Map<String, dynamic>).keys,"
           "($varExpression as Map).values.map(($itemVal) => $itemSubVal))";
     } else if (searchType.isDynamic || searchType.isObject) {
       // just return it as-is. We'll hope it's safe.
@@ -396,7 +416,7 @@ class JsonSerializableGenerator
       return "$varExpression as $searchType";
     }
 
-    return "$varExpression /* unsafe */";
+    throw new _UnsupportedTypeError(searchType, varExpression);
   }
 }
 
@@ -414,10 +434,10 @@ String _fieldToJsonMapKey(String fieldName, FieldElement field) {
   return fieldName;
 }
 
-DartType _getIterableGenericType(InterfaceType type) =>
+DartType _getIterableGenericType(DartType type) =>
     _getTypeArguments(type, _coreIterableChecker).single;
 
-List<DartType> _getTypeArguments(InterfaceType type, TypeChecker checker) {
+List<DartType> _getTypeArguments(DartType type, TypeChecker checker) {
   var iterableImplementation =
       _getImplementationType(type, checker) as InterfaceType;
 
@@ -457,3 +477,10 @@ final _stringBoolNumChecker = new TypeChecker.any([
   new TypeChecker.fromUrl('dart:core#bool'),
   new TypeChecker.fromUrl('dart:core#num')
 ]);
+
+class _UnsupportedTypeError extends Error {
+  final String expression;
+  final DartType type;
+
+  _UnsupportedTypeError(this.type, this.expression);
+}

lib/src/type_helper.dart

@@ -93,7 +93,8 @@ class JsonHelper extends TypeHelper {
   @override
   String deserialize(DartType targetType, String expression) {
     // TODO: the type could be imported from a library with a prefix!
-    return "new ${targetType.name}.fromJson($expression)";
+    // github.com/dart-lang/json_serializable/issues/19
+    return "new ${targetType.name}.fromJson($expression as Map<String, dynamic>)";
   }
 }
 
@@ -114,5 +115,7 @@ class DateTimeHelper extends TypeHelper {
 
   @override
   String deserialize(DartType targetType, String expression) =>
-      "DateTime.parse($expression)";
+      // TODO(kevmoo) `String` here is ignoring
+      // github.com/dart-lang/json_serializable/issues/19
+      "DateTime.parse($expression as String)";
 }

pubspec.yaml

@@ -1,5 +1,5 @@
 name: json_serializable
-version: 0.1.1-dev
+version: 0.2.0-dev
 author: Dart Team <misc@dartlang.org>
 description: Generates utilities to aid in serializing to/from JSON.
 homepage: https://github.com/dart-lang/json_serializable

test/analysis_utils.dart

@@ -13,7 +13,6 @@ import 'package:analyzer/source/pub_package_map_provider.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart' show FolderBasedDartSdk;
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
-import 'package:analyzer/src/generated/sdk.dart' show DartSdk;
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:cli_util/cli_util.dart' as cli;
@@ -26,7 +25,7 @@ Future<AnalysisContext> getAnalysisContextForProjectPath(
   var sdkPath = cli.getSdkPath();
 
   var resourceProvider = PhysicalResourceProvider.INSTANCE;
-  DartSdk sdk = new FolderBasedDartSdk(
+  var sdk = new FolderBasedDartSdk(
       resourceProvider, resourceProvider.getFolder(sdkPath));
 
   var packageResolver = _getPackageResolver(projectPath, sdk);
@@ -51,7 +50,7 @@ Future<AnalysisContext> getAnalysisContextForProjectPath(
   return context;
 }
 
-UriResolver _getPackageResolver(String projectPath, DartSdk sdk) {
+UriResolver _getPackageResolver(String projectPath, FolderBasedDartSdk sdk) {
   var dotPackagesPath = p.join(projectPath, '.packages');
 
   if (!FileSystemEntity.isFileSync(dotPackagesPath)) {
@@ -62,7 +61,7 @@ UriResolver _getPackageResolver(String projectPath, DartSdk sdk) {
   var pubPackageMapProvider =
       new PubPackageMapProvider(PhysicalResourceProvider.INSTANCE, sdk);
   var packageMapInfo = pubPackageMapProvider.computePackageMap(
-      PhysicalResourceProvider.INSTANCE.getResource(projectPath));
+      PhysicalResourceProvider.INSTANCE.getResource(projectPath) as Folder);
   var packageMap = packageMapInfo.packageMap;
   if (packageMap == null) {
     throw new StateError('An error occurred getting the package map.');