Enable 'dot-shorthands' feature flag for Dart 3.10

kallentu · Commit Queue · commit f93aea7c54f1 · 2025-08-18T12:38:35.000-07:00
This CL enables the dot shorthand feature by default in Dart 3.10. Dot shorthands allow you to omit the type name when accessing a static member in a context where that type is expected. These are some examples of ways you can use dot shorthands: ```dart Color color = .blue; switch (color) { case .blue: print('blue'); case .red: print('red'); case .green: print('green'); } ``` ```dart Column( crossAxisAlignment: .start, mainAxisSize: .min, children: widgets, ) ``` To learn more about the feature, check out the feature specification located here: https://github.com/dart-lang/language/blob/main/working/3616%20-%20enum%20value%20shorthand/proposal-simple-lrhn.md Tested: Feature tested with language tests and unit tests for the frontends, VM, web. Bug: #57036 Fixes: #57037 Change-Id: I4e2cab29e33ed266603942eaebf3f9671ef60766 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/427802 Reviewed-by: Bob Nystrom <rnystrom@google.com> Reviewed-by: Paul Berry <paulberry@google.com> Reviewed-by: Michael Thomsen <mit@google.com> Commit-Queue: Kallen Tu <kallentu@google.com> Reviewed-by: Ben Konyi <bkonyi@google.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,46 @@
 
 **Released on:** Unreleased
 
+### Language
+
+Dart 3.10 adds [dot shorthands][dot-shorthand-spec] to the language. To use
+them, set your package's [SDK constraint][language version] lower bound to 3.10
+or greater (`sdk: '^3.10.0'`).
+
+#### Dot shorthands
+
+Dot shorthands allow you to omit the type name when accessing a static member
+in a context where that type is expected.
+
+These are some examples of ways you can use dot shorthands:
+
+```dart
+Color color = .blue;
+switch (color) {
+  case .blue:
+    print('blue');
+  case .red:
+    print('red');
+  case .green:
+    print('green');
+}
+```
+
+```dart
+Column(
+  crossAxisAlignment: .start,
+  mainAxisSize: .min,
+  children: widgets,
+)
+```
+
+To learn more about the feature, check out the
+[feature specification][dot-shorthand-spec].
+
+[dot-shorthand-spec]: https://github.com/dart-lang/language/blob/main/working/3616%20-%20enum%20value%20shorthand/proposal-simple-lrhn.md
+
+### Tools
+
 #### Dart CLI and Dart VM
 
 - The Dart CLI and Dart VM have been split into two seperate executables.
diff --git a/pkg/_fe_analyzer_shared/lib/src/experiments/flags.dart b/pkg/_fe_analyzer_shared/lib/src/experiments/flags.dart
@@ -68,9 +68,9 @@ enum ExperimentalFlag {
 
   dotShorthands(
     name: 'dot-shorthands',
-    isEnabledByDefault: false,
+    isEnabledByDefault: true,
     isExpired: false,
-    experimentEnabledVersion: defaultLanguageVersion,
+    experimentEnabledVersion: const Version(3, 10),
     experimentReleasedVersion: const Version(3, 9),
   ),
 
diff --git a/pkg/analyzer/lib/src/dart/analysis/experiments.g.dart b/pkg/analyzer/lib/src/dart/analysis/experiments.g.dart
@@ -269,7 +269,7 @@ class ExperimentalFeatures {
     isExpired: IsExpired.dot_shorthands,
     documentation: 'Shorter dot syntax for static accesses.',
     experimentalReleaseVersion: Version.parse('3.9.0'),
-    releaseVersion: null,
+    releaseVersion: Version.parse('3.10.0'),
     channels: ["stable", "beta", "dev", "main"],
   );
 
@@ -648,7 +648,7 @@ class IsEnabledByDefault {
   static const bool digit_separators = true;
 
   /// Default state of the experiment "dot-shorthands"
-  static const bool dot_shorthands = false;
+  static const bool dot_shorthands = true;
 
   /// Default state of the experiment "enhanced-enums"
   static const bool enhanced_enums = true;
diff --git a/pkg/analyzer/test/generated/recovery_parser_test.dart b/pkg/analyzer/test/generated/recovery_parser_test.dart
@@ -483,11 +483,7 @@ class B = Object with A {}''',
   void test_dotShorthand_missing_identifier() {
     var result = parseExpression(
       ".",
-      codes: [
-        ParserErrorCode.missingIdentifier,
-        ParserErrorCode.experimentNotEnabled,
-        ParserErrorCode.experimentNotEnabled,
-      ],
+      codes: [ParserErrorCode.missingIdentifier],
     );
     var expression = result as DotShorthandPropertyAccess;
     expect(expression.period.lexeme, '.');
diff --git a/pkg/analyzer/test/src/dart/analysis/analysis_context_collection_test.dart b/pkg/analyzer/test/src/dart/analysis/analysis_context_collection_test.dart
@@ -403,6 +403,7 @@ analysisOptions
       constructor-tearoffs
       control-flow-collections
       digit-separators
+      dot-shorthands
       enhanced-enums
       extension-methods
       generic-metadata
@@ -484,6 +485,7 @@ analysisOptions
       constructor-tearoffs
       control-flow-collections
       digit-separators
+      dot-shorthands
       enhanced-enums
       extension-methods
       generic-metadata
diff --git a/pkg/analyzer_testing/lib/experiments/experiments.dart b/pkg/analyzer_testing/lib/experiments/experiments.dart
@@ -16,7 +16,6 @@ import 'package:analyzer/dart/analysis/features.dart';
 /// whether a given flag is already included.
 List<String> experimentsForTests = [
   Feature.augmentations.enableString,
-  Feature.dot_shorthands.enableString,
   Feature.enhanced_parts.enableString,
   Feature.macros.enableString,
   Feature.variance.enableString,
diff --git a/pkg/front_end/lib/src/api_prototype/experimental_flags_generated.dart b/pkg/front_end/lib/src/api_prototype/experimental_flags_generated.dart
@@ -118,10 +118,10 @@ class ExperimentalFlag {
 
   static const ExperimentalFlag dotShorthands = const ExperimentalFlag(
       name: 'dot-shorthands',
-      isEnabledByDefault: false,
+      isEnabledByDefault: true,
       isExpired: false,
-      enabledVersion: defaultLanguageVersion,
-      experimentEnabledVersion: defaultLanguageVersion,
+      enabledVersion: const Version(3, 10),
+      experimentEnabledVersion: const Version(3, 10),
       experimentReleasedVersion: const Version(3, 9));
 
   static const ExperimentalFlag enhancedEnums = const ExperimentalFlag(
diff --git a/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.expect b/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.expect
@@ -2,11 +2,6 @@ library;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
-// Try passing the '--enable-experiment=dot-shorthands' command line option.
-// test() => A.const.toString();
-//                  ^
-//
 // pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
 // Try inserting an identifier before 'const'.
 // test() => A.const.toString();
diff --git a/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.modular.expect b/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.modular.expect
@@ -2,11 +2,6 @@ library;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
-// Try passing the '--enable-experiment=dot-shorthands' command line option.
-// test() => A.const.toString();
-//                  ^
-//
 // pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
 // Try inserting an identifier before 'const'.
 // test() => A.const.toString();
diff --git a/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.transformed.expect b/pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.transformed.expect
@@ -2,11 +2,6 @@ library;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
-// Try passing the '--enable-experiment=dot-shorthands' command line option.
-// test() => A.const.toString();
-//                  ^
-//
 // pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
 // Try inserting an identifier before 'const'.
 // test() => A.const.toString();
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart
@@ -0,0 +1,11 @@
+// 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.
+
+// @dart=3.8
+
+enum Color { red, blue, green }
+
+void main() {
+  Color c = .red;
+}
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.expect
@@ -0,0 +1,46 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/feature_disabled.dart:10:13: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
+// Try passing the '--enable-experiment=dot-shorthands' command line option.
+//   Color c = .red;
+//             ^
+//
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::_Enum /*isEnum*/  {
+  enum-element static const field self::Color red = #C3;
+  enum-element static const field self::Color blue = #C6;
+  enum-element static const field self::Color green = #C9;
+  static const field core::List<self::Color> values = #C10;
+  const synthetic constructor •(core::int #index, core::String #name) → self::Color
+    : super core::_Enum::•(#index, #name)
+    ;
+  method core::_enumToString() → core::String
+    return "Color.${this.{core::_Enum::_name}{core::String}}";
+}
+static method main() → void {
+  self::Color c = #C3;
+}
+
+constants  {
+  #C1 = 0
+  #C2 = "red"
+  #C3 = self::Color {index:#C1, _name:#C2}
+  #C4 = 1
+  #C5 = "blue"
+  #C6 = self::Color {index:#C4, _name:#C5}
+  #C7 = 2
+  #C8 = "green"
+  #C9 = self::Color {index:#C7, _name:#C8}
+  #C10 = <self::Color>[#C3, #C6, #C9]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///feature_disabled.dart:
+- Color. (from org-dartlang-testcase:///feature_disabled.dart:7:6)
+- _Enum. (from org-dartlang-sdk:///sdk/lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.modular.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.modular.expect
@@ -0,0 +1,46 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/feature_disabled.dart:10:13: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
+// Try passing the '--enable-experiment=dot-shorthands' command line option.
+//   Color c = .red;
+//             ^
+//
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::_Enum /*isEnum*/  {
+  enum-element static const field self::Color red = #C3;
+  enum-element static const field self::Color blue = #C6;
+  enum-element static const field self::Color green = #C9;
+  static const field core::List<self::Color> values = #C10;
+  const synthetic constructor •(core::int #index, core::String #name) → self::Color
+    : super core::_Enum::•(#index, #name)
+    ;
+  method core::_enumToString() → core::String
+    return "Color.${this.{core::_Enum::_name}{core::String}}";
+}
+static method main() → void {
+  self::Color c = #C3;
+}
+
+constants  {
+  #C1 = 0
+  #C2 = "red"
+  #C3 = self::Color {index:#C1, _name:#C2}
+  #C4 = 1
+  #C5 = "blue"
+  #C6 = self::Color {index:#C4, _name:#C5}
+  #C7 = 2
+  #C8 = "green"
+  #C9 = self::Color {index:#C7, _name:#C8}
+  #C10 = <self::Color>[#C3, #C6, #C9]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///feature_disabled.dart:
+- Color. (from org-dartlang-testcase:///feature_disabled.dart:7:6)
+- _Enum. (from org-dartlang-sdk:///sdk/lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.outline.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.outline.expect
@@ -0,0 +1,25 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::_Enum /*isEnum*/  {
+  enum-element static const field self::Color red = const self::Color::•(0, "red");
+  enum-element static const field self::Color blue = const self::Color::•(1, "blue");
+  enum-element static const field self::Color green = const self::Color::•(2, "green");
+  static const field core::List<self::Color> values = const <self::Color>[self::Color::red, self::Color::blue, self::Color::green];
+  const synthetic constructor •(core::int #index, core::String #name) → self::Color
+    : super core::_Enum::•(#index, #name)
+    ;
+  method core::_enumToString() → core::String
+    return "Color.${this.{core::_Enum::_name}{core::String}}";
+}
+static method main() → void
+  ;
+
+
+Extra constant evaluation status:
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///feature_disabled.dart:7:14 -> InstanceConstant(const Color{_Enum.index: 0, _Enum._name: "red"})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///feature_disabled.dart:7:19 -> InstanceConstant(const Color{_Enum.index: 1, _Enum._name: "blue"})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///feature_disabled.dart:7:25 -> InstanceConstant(const Color{_Enum.index: 2, _Enum._name: "green"})
+Evaluated: ListLiteral @ org-dartlang-testcase:///feature_disabled.dart:7:6 -> ListConstant(const <Color>[const Color{_Enum.index: 0, _Enum._name: "red"}, const Color{_Enum.index: 1, _Enum._name: "blue"}, const Color{_Enum.index: 2, _Enum._name: "green"}])
+Extra constant evaluation: evaluated: 9, effectively constant: 4
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.transformed.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.strong.transformed.expect
@@ -0,0 +1,46 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dot_shorthands/feature_disabled.dart:10:13: Error: This requires the experimental 'dot-shorthands' language feature to be enabled.
+// Try passing the '--enable-experiment=dot-shorthands' command line option.
+//   Color c = .red;
+//             ^
+//
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::_Enum /*isEnum*/  {
+  enum-element static const field self::Color red = #C3;
+  enum-element static const field self::Color blue = #C6;
+  enum-element static const field self::Color green = #C9;
+  static const field core::List<self::Color> values = #C10;
+  const synthetic constructor •(core::int #index, core::String #name) → self::Color
+    : super core::_Enum::•(#index, #name)
+    ;
+  method core::_enumToString() → core::String
+    return "Color.${this.{core::_Enum::_name}{core::String}}";
+}
+static method main() → void {
+  self::Color c = #C3;
+}
+
+constants  {
+  #C1 = 0
+  #C2 = "red"
+  #C3 = self::Color {index:#C1, _name:#C2}
+  #C4 = 1
+  #C5 = "blue"
+  #C6 = self::Color {index:#C4, _name:#C5}
+  #C7 = 2
+  #C8 = "green"
+  #C9 = self::Color {index:#C7, _name:#C8}
+  #C10 = <self::Color>[#C3, #C6, #C9]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///feature_disabled.dart:
+- Color. (from org-dartlang-testcase:///feature_disabled.dart:7:6)
+- _Enum. (from org-dartlang-sdk:///sdk/lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.textual_outline.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.textual_outline.expect
@@ -0,0 +1,5 @@
+// @dart = 3.8
+
+enum Color { red, blue, green }
+
+void main() {}
diff --git a/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/dot_shorthands/feature_disabled.dart.textual_outline_modelled.expect
@@ -0,0 +1,5 @@
+// @dart = 3.8
+
+enum Color { red, blue, green }
+
+void main() {}
diff --git a/runtime/vm/experimental_features.cc b/runtime/vm/experimental_features.cc
@@ -18,7 +18,7 @@ bool GetExperimentalFeatureDefault(ExperimentalFeature feature) {
   constexpr bool kFeatureValues[] = {
       true, true, true, true, true, true, true, true, true, true,
       true, true, true, true, true, true, true, true, true, true,
-      true, true, true, true, true, true, true, true, true,
+      true, true, true, true, true, true, true, true, true, true,
   };
   ASSERT(static_cast<size_t>(feature) < ARRAY_SIZE(kFeatureValues));
   return kFeatureValues[static_cast<int>(feature)];
@@ -27,6 +27,7 @@ bool GetExperimentalFeatureDefault(ExperimentalFeature feature) {
 const char* GetExperimentalFeatureName(ExperimentalFeature feature) {
   constexpr const char* kFeatureNames[] = {
       "native-assets",
+      "dot-shorthands",
       "getter-setter-error",
       "sound-flow-analysis",
       "null-aware-elements",
diff --git a/runtime/vm/experimental_features.h b/runtime/vm/experimental_features.h
@@ -13,6 +13,7 @@ namespace dart {
 
 enum class ExperimentalFeature {
   native_assets,
+  dot_shorthands,
   getter_setter_error,
   sound_flow_analysis,
   null_aware_elements,
diff --git a/tests/language/dot_shorthands/feature_enabled_error_test.dart b/tests/language/dot_shorthands/feature_enabled_error_test.dart
diff --git a/tests/language/dot_shorthands/feature_enabled_test.dart b/tests/language/dot_shorthands/feature_enabled_test.dart
diff --git a/tests/language/explicit_type_instantiation_parsing_test.dart b/tests/language/explicit_type_instantiation_parsing_test.dart
diff --git a/tools/experimental_features.yaml b/tools/experimental_features.yaml
