quick fix for prefer_const_literals_to_create_immutables

see: https://github.com/dart-lang/sdk/issues/45932

Fixes: https://github.com/dart-lang/sdk/issues/45924

Change-Id: I98d89e9f98b72c333f9bb274b84730d68b71e71f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/206102
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/services/correction/dart/add_const.dart

@@ -37,6 +37,25 @@ class AddConst extends CorrectionProducer {
       });
       return;
     }
+
+    Future<void> insertAtOffset(AstNode targetNode) async {
+      await builder.addDartFileEdit(file, (builder) {
+        builder.addSimpleInsertion(targetNode.offset, 'const ');
+      });
+    }
+
+    // todo(pq):consider removing nested `const` declarations
+    // made unnecessary by outer ones in List, Set literal and
+    // instance creations.
+
+    if (targetNode is ListLiteral) {
+      await insertAtOffset(targetNode);
+      return;
+    }
+    if (targetNode is SetOrMapLiteral) {
+      await insertAtOffset(targetNode);
+      return;
+    }
     if (targetNode is TypeName) {
       targetNode = targetNode.parent;
     }
@@ -45,10 +64,8 @@ class AddConst extends CorrectionProducer {
     }
     if (targetNode is InstanceCreationExpression) {
       if (targetNode.keyword == null) {
-        var node_final = targetNode;
-        await builder.addDartFileEdit(file, (builder) {
-          builder.addSimpleInsertion(node_final.offset, 'const ');
-        });
+        await insertAtOffset(targetNode);
+        return;
       }
     }
   }
@@ -61,4 +78,7 @@ class AddConst extends CorrectionProducer {
   //  with the `unnecessary_const` lint. Fix it and then enable it for both
   //  uses.
   static AddConst toInvocation() => AddConst(false, false);
+
+  /// Return an instance of this class. Used as a tear-off in `FixProcessor`.
+  static AddConst toLiteral() => AddConst(true, true);
 }

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -439,6 +439,9 @@ class FixProcessor extends BaseProcessor {
     LintNames.prefer_const_declarations: [
       ReplaceFinalWithConst.newInstance,
     ],
+    LintNames.prefer_const_literals_to_create_immutables: [
+      AddConst.toLiteral,
+    ],
     LintNames.prefer_contains: [
       ConvertToContains.newInstance,
     ],

pkg/analysis_server/lib/src/services/linter/lint_names.dart

@@ -60,6 +60,8 @@ class LintNames {
   static const String prefer_const_constructors_in_immutables =
       'prefer_const_constructors_in_immutables';
   static const String prefer_const_declarations = 'prefer_const_declarations';
+  static const String prefer_const_literals_to_create_immutables =
+      'prefer_const_literals_to_create_immutables';
   static const String prefer_contains = 'prefer_contains';
   static const String prefer_equal_for_default_values =
       'prefer_equal_for_default_values';

pkg/analysis_server/test/src/services/correction/fix/add_const_test.dart

@@ -11,10 +11,13 @@ import 'fix_processor.dart';
 
 void main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(AddConst_PreferConstConstructorsBulkTest);
     defineReflectiveTests(AddConst_PreferConstConstructorsInImmutablesBulkTest);
     defineReflectiveTests(AddConst_PreferConstConstructorsInImmutablesTest);
+    defineReflectiveTests(AddConst_PreferConstConstructorsBulkTest);
     defineReflectiveTests(AddConst_PreferConstConstructorsTest);
+    defineReflectiveTests(
+        AddConst_PreferConstLiteralsToCreateImmutablesBulkTest);
+    defineReflectiveTests(AddConst_PreferConstLiteralsToCreateImmutablesTest);
   });
 }
 
@@ -175,3 +178,159 @@ void f() {
 ''');
   }
 }
+
+@reflectiveTest
+class AddConst_PreferConstLiteralsToCreateImmutablesBulkTest
+    extends BulkFixProcessorTest {
+  @override
+  String get lintCode => LintNames.prefer_const_literals_to_create_immutables;
+
+  @override
+  void setUp() {
+    super.setUp();
+    writeTestPackageConfig(
+      meta: true,
+    );
+  }
+
+  Future<void> test_map() async {
+    await resolveTestCode('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Map children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: {
+    1 : {}
+  });
+  print(c);
+}
+''');
+    await assertHasFix('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Map children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: const {
+    1 : const {}
+  });
+  print(c);
+}
+''');
+  }
+}
+
+@reflectiveTest
+class AddConst_PreferConstLiteralsToCreateImmutablesTest
+    extends FixProcessorLintTest {
+  @override
+  FixKind get kind => DartFixKind.ADD_CONST;
+
+  @override
+  String get lintCode => LintNames.prefer_const_literals_to_create_immutables;
+  @override
+  void setUp() {
+    super.setUp();
+    writeTestPackageConfig(
+      meta: true,
+    );
+  }
+
+  Future<void> test_list() async {
+    await resolveTestCode('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final List<C> children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: []);
+  print(c);
+}
+''');
+    await assertHasFix('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final List<C> children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: const []);
+  print(c);
+}
+''');
+  }
+
+  Future<void> test_map() async {
+    await resolveTestCode('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Map children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: {
+    1 : const {}
+  });
+  print(c);
+}
+''');
+    await assertHasFix('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Map children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: const {
+    1 : const {}
+  });
+  print(c);
+}
+''');
+  }
+
+  Future<void> test_set() async {
+    await resolveTestCode('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Set<C> children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: {});
+  print(c);
+}
+''');
+    await assertHasFix('''
+import 'package:meta/meta.dart';
+
+@immutable
+class C {
+  final Set<C> children;
+  const C({required this.children});
+}
+void f() {
+  var c = C(children: const {});
+  print(c);
+}
+''');
+  }
+}