Migration: clean up and test implicit dynamic return type of Function() syntax.

stereotype441 · commit-bot@chromium.org · commit b57ff8590648 · 2019-06-30T16:39:17.000Z
Change-Id: I6a010f5aa32cee4ece094188992ba472444293c3 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107519 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/nnbd_migration/lib/src/node_builder.dart b/pkg/nnbd_migration/lib/src/node_builder.dart
@@ -57,20 +57,6 @@ class NodeBuilder extends GeneralizingAstVisitor<DecoratedType> {
       : _nonNullableObjectType =
             DecoratedType(_typeProvider.objectType, _graph.never);
 
-  /// Creates and stores a [DecoratedType] object corresponding to the given
-  /// [type] AST, and returns it.
-  DecoratedType decorateType(TypeAnnotation type, AstNode enclosingNode) {
-    return type == null
-        // TODO(danrubel): Return something other than this
-        // to indicate that we should insert a type for the declaration
-        // that is missing a type reference.
-        ? new DecoratedType(
-            DynamicTypeImpl.instance,
-            NullabilityNode.forInferredDynamicType(
-                _graph, _source, enclosingNode.offset))
-        : type.accept(this);
-  }
-
   @override
   DecoratedType visitClassDeclaration(ClassDeclaration node) {
     node.metadata.accept(this);
@@ -254,7 +240,7 @@ $stackTrace''');
       return decoratedType;
     }
     var typeArguments = const <DecoratedType>[];
-    DecoratedType returnType;
+    DecoratedType decoratedReturnType;
     var positionalParameters = const <DecoratedType>[];
     var namedParameters = const <String, DecoratedType>{};
     if (type is InterfaceType && type.typeParameters.isNotEmpty) {
@@ -272,7 +258,10 @@ $stackTrace''');
       }
     }
     if (node is GenericFunctionType) {
-      returnType = decorateType(node.returnType, node);
+      var returnType = node.returnType;
+      decoratedReturnType = returnType == null
+          ? DecoratedType.forImplicitType(DynamicTypeImpl.instance, _graph)
+          : returnType.accept(this);
       if (node.typeParameters != null) {
         // TODO(paulberry)
         _unimplemented(node, 'Generic function type with type parameters');
@@ -305,7 +294,7 @@ $stackTrace''');
     }
     var decoratedType = DecoratedTypeAnnotation(type, nullabilityNode, node.end,
         typeArguments: typeArguments,
-        returnType: returnType,
+        returnType: decoratedReturnType,
         positionalParameters: positionalParameters,
         namedParameters: namedParameters);
     _variables.recordDecoratedTypeAnnotation(_source, node, decoratedType);
diff --git a/pkg/nnbd_migration/test/api_test.dart b/pkg/nnbd_migration/test/api_test.dart
@@ -862,6 +862,22 @@ int? test(C c) {
     await _checkSingleFileChanges(content, expected);
   }
 
+  test_generic_function_type_syntax_inferred_dynamic_return() async {
+    var content = '''
+abstract class C {
+  Function() f();
+}
+Object g(C c) => c.f()();
+''';
+    var expected = '''
+abstract class C {
+  Function() f();
+}
+Object? g(C c) => c.f()();
+''';
+    await _checkSingleFileChanges(content, expected);
+  }
+
   test_genericType_noTypeArguments() async {
     var content = '''
 void f(C c) {}
diff --git a/pkg/nnbd_migration/test/node_builder_test.dart b/pkg/nnbd_migration/test/node_builder_test.dart
@@ -415,6 +415,19 @@ class C {
         same(decoratedType));
   }
 
+  test_generic_function_type_syntax_inferred_dynamic_return() async {
+    await analyze('''
+abstract class C {
+  Function() f();
+}
+''');
+    var decoratedFType = decoratedMethodType('f');
+    var decoratedFReturnType = decoratedFType.returnType;
+    var decoratedFReturnReturnType = decoratedFReturnType.returnType;
+    expect(decoratedFReturnReturnType.type.toString(), 'dynamic');
+    expect(decoratedFReturnReturnType.node, same(always));
+  }
+
   test_genericFunctionType_namedParameterType() async {
     await analyze('''
 void f(void Function({int y}) x) {}
