[cfe] Disallow '.new<int>' and type parameters on constructors for dot shorthands.

Adds errors for this part of the spec behaviour: `.new<typeArgs> and .new<typeArgs>(args) will always be compile-time errors because .new denotes a constructor which is not generic`

Bug: #59758
Change-Id: I76074d2314f40f60015324d4b01ece7477a8ffb4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/417880
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

Author: kallentu

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -3236,6 +3236,20 @@ const MessageCode messageDirectiveAfterDeclaration = const MessageCode(
   correctionMessage: r"""Try moving the directive before any declarations.""",
 );
 
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Null> codeDotShorthandsConstructorInvocationWithTypeArguments =
+    messageDotShorthandsConstructorInvocationWithTypeArguments;
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const MessageCode messageDotShorthandsConstructorInvocationWithTypeArguments =
+    const MessageCode(
+  "DotShorthandsConstructorInvocationWithTypeArguments",
+  problemMessage:
+      r"""A dot shorthand constructor invocation can't have type arguments.""",
+  correctionMessage:
+      r"""Try adding the class name and type arguments explicitly before the constructor name.""",
+);
+
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Template<Message Function(String name)>
     templateDotShorthandsInvalidContext =

pkg/front_end/lib/src/type_inference/inference_visitor.dart

@@ -12146,14 +12146,24 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       // a constructor of that name instead.
       Member? constructor =
           findConstructor(cachedContext, node.name, node.fileOffset);
+
+      // Dot shorthand constructor invocations with type parameters
+      // `.id<type>()` are not allowed.
+      if (constructor != null && node.arguments.types.isNotEmpty) {
+        return new ExpressionInferenceResult(
+            const DynamicType(),
+            helper.buildProblem(
+                messageDotShorthandsConstructorInvocationWithTypeArguments,
+                node.nameOffset,
+                node.name.text.length));
+      }
+
       if (constructor is Constructor) {
         if (!constructor.isConst && node.isConst) {
-          Expression replacement = helper.buildProblem(
-              messageNonConstConstructor,
-              node.nameOffset,
-              node.name.text.length);
           return new ExpressionInferenceResult(
-              const DynamicType(), replacement);
+              const DynamicType(),
+              helper.buildProblem(messageNonConstConstructor, node.nameOffset,
+                  node.name.text.length));
         }
 
         expr = new ConstructorInvocation(constructor, node.arguments,
@@ -12164,12 +12174,10 @@ class InferenceVisitorImpl extends InferenceVisitorBase
         // constructor or a redirecting factory constructor.
         if (!constructor.isConst && node.isConst) {
           // Coverage-ignore-block(suite): Not run.
-          Expression replacement = helper.buildProblem(
-              messageNonConstConstructor,
-              node.nameOffset,
-              node.name.text.length);
           return new ExpressionInferenceResult(
-              const DynamicType(), replacement);
+              const DynamicType(),
+              helper.buildProblem(messageNonConstConstructor, node.nameOffset,
+                  node.name.text.length));
         }
 
         if (constructor.isRedirectingFactory) {

pkg/front_end/messages.status

@@ -200,6 +200,7 @@ DirectiveAfterDeclaration/part_wrapped_script1: Fail
 DirectiveAfterDeclaration/part_wrapped_script2: Fail
 DirectiveAfterDeclaration/script1: Fail
 DirectiveAfterDeclaration/script2: Fail
+DotShorthandsConstructorInvocationWithTypeArguments/analyzerCode: Fail # TODO(kallentu): https://github.com/dart-lang/sdk/issues/59835
 DotShorthandsInvalidContext/analyzerCode: Fail # TODO(kallentu): https://github.com/dart-lang/sdk/issues/59835
 DotShorthandsUndefinedGetter/analyzerCode: Fail # TODO(kallentu): https://github.com/dart-lang/sdk/issues/59835
 DotShorthandsUndefinedInvocation/analyzerCode: Fail # TODO(kallentu): https://github.com/dart-lang/sdk/issues/59835

pkg/front_end/messages.yaml

@@ -7421,6 +7421,18 @@ ImplicitSuperInitializerMissingArguments:
   script: |
     class A { A(int foo); } class B extends A { B(); }
 
+DotShorthandsConstructorInvocationWithTypeArguments:
+  problemMessage: "A dot shorthand constructor invocation can't have type arguments."
+  correctionMessage: "Try adding the class name and type arguments explicitly before the constructor name."
+  experiments: dot-shorthands
+  script: >
+    class C<X> {
+      C.foo();
+    }
+    void main() {
+      C c = .foo<int>();
+    }
+
 DotShorthandsInvalidContext:
   problemMessage: "No type was provided to find the dot shorthand '#name'."
   experiments: dot-shorthands

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart

@@ -0,0 +1,14 @@
+// Copyright (c) 2025, 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.
+
+class C {
+  C();
+  C.named();
+}
+
+void test() {
+  C newConstructor = .new<int>();
+  C namedConstructor = .named<int>();
+  C newTearoff = .new<int>;
+}

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.strong.expect

@@ -0,0 +1,50 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C newConstructor = .new<int>();
+//                       ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C namedConstructor = .named<int>();
+//                         ^^^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:19: Error: The static getter or field 'new' isn't defined for the type 'C'.
+//  - 'C' is from 'pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart'.
+// Try correcting the name to the name of an existing static getter or field, or defining a getter or field named 'new'.
+//   C newTearoff = .new<int>;
+//                   ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+// Try changing the operand or remove the type arguments.
+//   C newTearoff = .new<int>;
+//                      ^
+//
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → self::C
+    : super core::Object::•()
+    ;
+  constructor named() → self::C
+    : super core::Object::•()
+    ;
+}
+static method test() → void {
+  self::C newConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C newConstructor = .new<int>();
+                      ^^^" as{TypeError,ForDynamic} self::C;
+  self::C namedConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C namedConstructor = .named<int>();
+                        ^^^^^" as{TypeError,ForDynamic} self::C;
+  self::C newTearoff = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+Try changing the operand or remove the type arguments.
+  C newTearoff = .new<int>;
+                     ^";
+}

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.strong.modular.expect

@@ -0,0 +1,50 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C newConstructor = .new<int>();
+//                       ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C namedConstructor = .named<int>();
+//                         ^^^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:19: Error: The static getter or field 'new' isn't defined for the type 'C'.
+//  - 'C' is from 'pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart'.
+// Try correcting the name to the name of an existing static getter or field, or defining a getter or field named 'new'.
+//   C newTearoff = .new<int>;
+//                   ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+// Try changing the operand or remove the type arguments.
+//   C newTearoff = .new<int>;
+//                      ^
+//
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → self::C
+    : super core::Object::•()
+    ;
+  constructor named() → self::C
+    : super core::Object::•()
+    ;
+}
+static method test() → void {
+  self::C newConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C newConstructor = .new<int>();
+                      ^^^" as{TypeError,ForDynamic} self::C;
+  self::C namedConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C namedConstructor = .named<int>();
+                        ^^^^^" as{TypeError,ForDynamic} self::C;
+  self::C newTearoff = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+Try changing the operand or remove the type arguments.
+  C newTearoff = .new<int>;
+                     ^";
+}

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.strong.outline.expect

@@ -0,0 +1,12 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → self::C
+    ;
+  constructor named() → self::C
+    ;
+}
+static method test() → void
+  ;

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.strong.transformed.expect

@@ -0,0 +1,50 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C newConstructor = .new<int>();
+//                       ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+// Try adding the class name and type arguments explicitly before the constructor name.
+//   C namedConstructor = .named<int>();
+//                         ^^^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:19: Error: The static getter or field 'new' isn't defined for the type 'C'.
+//  - 'C' is from 'pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart'.
+// Try correcting the name to the name of an existing static getter or field, or defining a getter or field named 'new'.
+//   C newTearoff = .new<int>;
+//                   ^^^
+//
+// pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+// Try changing the operand or remove the type arguments.
+//   C newTearoff = .new<int>;
+//                      ^
+//
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → self::C
+    : super core::Object::•()
+    ;
+  constructor named() → self::C
+    : super core::Object::•()
+    ;
+}
+static method test() → void {
+  self::C newConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:11:23: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C newConstructor = .new<int>();
+                      ^^^" as{TypeError,ForDynamic,Unchecked} self::C;
+  self::C namedConstructor = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:12:25: Error: A dot shorthand constructor invocation can't have type arguments.
+Try adding the class name and type arguments explicitly before the constructor name.
+  C namedConstructor = .named<int>();
+                        ^^^^^" as{TypeError,ForDynamic,Unchecked} self::C;
+  self::C newTearoff = invalid-expression "pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart:13:22: Error: The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
+Try changing the operand or remove the type arguments.
+  C newTearoff = .new<int>;
+                     ^";
+}

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.textual_outline.expect

@@ -0,0 +1,6 @@
+class C {
+  C();
+  C.named();
+}
+
+void test() {}

pkg/front_end/testcases/dot_shorthands/constructor_type_parameter_error.dart.textual_outline_modelled.expect

@@ -0,0 +1,6 @@
+class C {
+  C();
+  C.named();
+}
+
+void test() {}

tests/language/dot_shorthands/type_parameter/type_parameter_error_test.dart

@@ -11,24 +11,26 @@ import '../dot_shorthand_helper.dart';
 
 void main() {
   StaticMember<int> s = .memberType<String, String>('s');
-  // ^
+  //                    ^
   // [analyzer] unspecified
-  // [cfe] unspecified
+  // [cfe] A value of type 'StaticMember<String>' can't be assigned to a variable of type 'StaticMember<int>'.
 
   // Constructors doesn't have type parameters.
   StaticMember<int> constructorTypeParameter = .constNamed<int>(1);
-  // ^
+  //                                            ^^^^^^^^^^
   // [analyzer] unspecified
-  // [cfe] unspecified
+  // [cfe] A dot shorthand constructor invocation can't have type arguments.
 
   // `.new<type-args>()` and `.new<type-args>` are a compile-time error.
   UnnamedConstructorTypeParameters typeParameters = .new<int>();
-  // ^
+  //                                                 ^^^
   // [analyzer] unspecified
-  // [cfe] unspecified
+  // [cfe] A dot shorthand constructor invocation can't have type arguments.
 
   UnnamedConstructorTypeParameters Function() tearOff = .new<int>;
-  // ^
+  //                                                     ^^^
   // [analyzer] unspecified
-  // [cfe] unspecified
+  // [cfe] The static getter or field 'new' isn't defined for the type 'UnnamedConstructorTypeParameters<dynamic> Function()'.
+  //                                                        ^
+  // [cfe] The static type of the explicit instantiation operand must be a generic function type but is 'dynamic'.
 }