Migrate impl to null safety and support latest source_gen dependency (#187)

Author: kevmoo

functions_framework/pubspec.yaml

@@ -23,5 +23,5 @@ dev_dependencies:
   build_verify: ^2.0.0
   json_serializable: ^4.0.0
   # Because we use the ignore_for_file build.yaml config
-  source_gen: ^0.9.5
+  source_gen: ^1.0.0
   test: ^1.15.7

functions_framework_builder/CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 0.4.0-dev
 
 - Generate null-safe code.
+- Migrate implementation to null safety.
 - Support the latest `package:functions_framework` version.
 - Allow the latest, null-safe versions of a number of packages.
 

functions_framework_builder/lib/builder.dart

@@ -33,7 +33,7 @@ import 'src/constants.dart';
 import 'src/function_type_validator.dart';
 import 'src/supported_function_type.dart';
 
-Builder functionsFrameworkBuilder([BuilderOptions options]) =>
+Builder functionsFrameworkBuilder([BuilderOptions? options]) =>
     const _FunctionsFrameworkBuilder();
 
 class _FunctionsFrameworkBuilder implements Builder {
@@ -62,12 +62,10 @@ class _FunctionsFrameworkBuilder implements Builder {
         );
       }
 
-      final function = element as FunctionElement;
-
       final targetReader = annotatedElement.annotation.read('target');
 
       final targetName =
-          targetReader.isNull ? function.name : targetReader.stringValue;
+          targetReader.isNull ? element.name : targetReader.stringValue;
 
       if (entries.containsKey(targetName)) {
         throw InvalidGenerationSourceError(
@@ -79,7 +77,7 @@ class _FunctionsFrameworkBuilder implements Builder {
       final invokeExpression = validator.validate(
         libraryElement,
         targetName,
-        function,
+        element,
       );
 
       entries[targetName] = invokeExpression;

functions_framework_builder/lib/src/generic_function_type.dart

@@ -41,14 +41,13 @@ class GenericFunctionType implements SupportedFunctionType {
   String get typedefName => _typedefName;
 
   @override
-  String get typeDescription => _functionTypeAliasElement.aliasedElement
+  String get typeDescription => _functionTypeAliasElement.aliasedElement!
       .getDisplayString(withNullability: false);
 
   final TypeAliasElement _functionTypeAliasElement;
   final bool _withContext;
 
-  GenericFunctionType._(this._functionTypeAliasElement, this._withContext)
-      : assert(_functionTypeAliasElement != null);
+  GenericFunctionType._(this._functionTypeAliasElement, this._withContext);
 
   static Future<GenericFunctionType> create(Resolver resolver) async {
     final lib = await resolver.libraryFor(AssetId.resolve(_libraryUri));
@@ -71,7 +70,7 @@ class GenericFunctionType implements SupportedFunctionType {
   }
 
   @override
-  FactoryData createReference(
+  FactoryData? createReference(
     LibraryElement library,
     String targetName,
     FunctionElement element,
@@ -101,11 +100,11 @@ class GenericFunctionType implements SupportedFunctionType {
 
     if (library.typeSystem.isSubtypeOf(element.type, functionType)) {
       if (paramInfo.paramType != null) {
-        if (library.exportNamespace.get(paramInfo.paramType.element.name) ==
+        if (library.exportNamespace.get(paramInfo.paramType!.element.name) ==
             null) {
           // TODO: add a test for this!
           throw InvalidGenerationSourceError(
-            'The type `${paramInfo.paramType.element.name}` is not exposed by '
+            'The type `${paramInfo.paramType!.element.name}` is not exposed by '
             'the function library `${library.source.uri}` so it cannot '
             'be used.',
           );
@@ -152,7 +151,7 @@ class _GenericFactoryData implements FactoryData {
     final typeDisplayName = info.paramType == null
         ? jsonTypeDisplay
         : '$functionsLibraryPrefix.'
-            '${info.paramType.getDisplayString(withNullability: false)}';
+            '${info.paramType!.getDisplayString(withNullability: false)}';
 
     final returnBlock = info.paramType == null
         ? 'return $_jsonParamName;'

functions_framework_builder/lib/src/supported_function_type.dart

@@ -26,13 +26,13 @@ class SupportedFunctionType {
   final String typeDescription;
 
   final FunctionType _type;
-  final String _constructor;
+  final String? _constructor;
 
   SupportedFunctionType._(
     this.libraryUri,
     this.typedefName,
     this._type, {
-    String constructor,
+    String? constructor,
   })  : _constructor = constructor,
         typeDescription = _type.getDisplayString(withNullability: false);
 
@@ -62,7 +62,7 @@ class SupportedFunctionType {
     );
   }
 
-  FactoryData createReference(
+  FactoryData? createReference(
     LibraryElement library,
     String targetName,
     FunctionElement element,

functions_framework_builder/lib/src/utils.dart

@@ -24,7 +24,7 @@ String escapeDartString(String value) {
   var canBeRaw = true;
 
   value = value.replaceAllMapped(_escapeRegExp, (match) {
-    final value = match[0];
+    final value = match[0]!;
     if (value == "'") {
       hasSingleQuote = true;
       return value;

functions_framework_builder/lib/src/valid_json_utils.dart

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import 'package:analyzer/dart/element/type.dart';
+import 'package:collection/collection.dart';
 
 const fromJsonFactoryName = 'fromJson';
 
@@ -49,17 +50,16 @@ bool _validJsonType(DartType type, bool allowComplexMembers) {
 
 class JsonParamInfo {
   final DartType jsonType;
-  final InterfaceType paramType;
+  final InterfaceType? paramType;
 
   JsonParamInfo._(this.jsonType, this.paramType);
 }
 
-JsonParamInfo validJsonParamType(DartType type) {
+JsonParamInfo? validJsonParamType(DartType type) {
   // Look for a `fromJson` factory that takes a JSON-able type
   if (type is InterfaceType) {
-    final fromJsonCtor = type.constructors.singleWhere(
+    final fromJsonCtor = type.constructors.singleWhereOrNull(
       (element) => element.name == fromJsonFactoryName,
-      orElse: () => null,
     );
     if (fromJsonCtor != null) {
       final requiredParams = fromJsonCtor.parameters
@@ -99,8 +99,7 @@ JsonReturnKind _validJsonReturnTypeCore(DartType type) {
 
   // Look for a `toJson` function that returns a JSON-able type
   if (type is InterfaceType) {
-    final interfaceType = type as InterfaceType;
-    final toJsonMethod = interfaceType.getMethod('toJson');
+    final toJsonMethod = type.getMethod('toJson');
     if (toJsonMethod != null &&
         toJsonMethod.parameters.every((element) => element.isOptional)) {
       type = toJsonMethod.returnType;

functions_framework_builder/pubspec.yaml

@@ -4,21 +4,22 @@ description: Builder for package:functions_framework
 repository: https://github.com/GoogleCloudPlatform/functions-framework-dart
 
 environment:
-  sdk: ">=2.11.99 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
   analyzer: ^1.0.0
   build: ^2.0.0
   build_config: ^0.4.3
-  dart_style: ^1.3.10
+  collection: ^1.15.0
+  dart_style: ^2.0.0
   # There is a tight version constraint because the builder has a strict
   # dependency on all features exposed.
   functions_framework: '>=0.4.0 <0.4.1'
   glob: ^2.0.0
   meta: ^1.2.4
   path: ^1.7.0
   shelf: ^1.0.0
-  source_gen: ^0.9.8
+  source_gen: ^1.0.0
 
 dev_dependencies:
   build_test: ^2.0.0

functions_framework_builder/test/builder_test.dart

@@ -185,8 +185,8 @@ $lines
             '(JsonType request, RequestContext context)',
           )
           .replaceAll(
-            'int other',
-            'RequestContext context, int other',
+            'int? other',
+            'RequestContext context, int? other',
           );
 
       await _testItems(
@@ -445,8 +445,8 @@ $lines
             '(num request, RequestContext context)',
           )
           .replaceAll(
-            'int other',
-            'RequestContext context, int other',
+            'int? other',
+            'RequestContext context, int? other',
           );
 
       await _testItems(
@@ -607,7 +607,7 @@ $entries
 
 Future<void> _generateTest(
   String inputLibrary,
-  String expectedContent, {
+  String? expectedContent, {
   bool validateLog = true,
 }) async {
   final srcs = {'$_pkgName|lib/functions.dart': inputLibrary};
@@ -633,7 +633,7 @@ Future<void> _generateTest(
       }
       addTearDown(() {
         var output = 'Unexpected log message: "${log.message}"';
-        if ((log.message == null || log.message.isEmpty) && log.error != null) {
+        if ((log.message.isEmpty) && log.error != null) {
           output = '$output (${log.error})';
         }
         fail(output);

functions_framework_builder/test/test_examples/valid_cloud_event_handlers.dart

@@ -27,7 +27,7 @@ FutureOr<void> futureOrFunction(CloudEvent request) =>
     throw UnimplementedError();
 
 @CloudFunction()
-void optionalParam([CloudEvent request]) => throw UnimplementedError();
+void optionalParam([CloudEvent? request]) => throw UnimplementedError();
 
 @CloudFunction()
 void objectParam(Object request) => throw UnimplementedError();