[analyzer] UNNECESSARY_SET_LITERAL to handle multiple expressions

Bug: https://github.com/dart-lang/sdk/issues/50900
Change-Id: Id09e102c2cc12c9043d3f6c22b3af3babf18920e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/284021
Reviewed-by: Nate Biggs <natebiggs@google.com>
Reviewed-by: Oleh Prypin <oprypin@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Oleh Prypin <oprypin@google.com>

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

@@ -101,7 +101,7 @@ class AssistProcessor extends BaseProcessor {
     ConvertDocumentationIntoLine.new,
     ConvertIfStatementToSwitchStatement.new,
     ConvertIntoAsyncBody.new,
-    ConvertIntoBlockBody.new,
+    ConvertIntoBlockBody.missingBody,
     ConvertIntoFinalField.new,
     ConvertIntoForIndex.new,
     ConvertIntoGetter.new,

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

@@ -2,6 +2,7 @@
 // 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.
 
+import 'package:_fe_analyzer_shared/src/scanner/token.dart';
 import 'package:analysis_server/src/services/correction/assist.dart';
 import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
@@ -16,14 +17,47 @@ import 'package:analyzer_plugin/utilities/range_factory.dart';
 import '../fix.dart';
 
 class ConvertIntoBlockBody extends ResolvedCorrectionProducer {
+  /// The kind of correction to be made.
+  final _CorrectionKind _correctionKind;
+
+  @override
+  bool canBeAppliedInBulk;
+
+  @override
+  bool canBeAppliedToFile;
+
+  /// Initialize a newly created instance that adds a function body.
+  ConvertIntoBlockBody.missingBody()
+      : _correctionKind = _CorrectionKind.missingBody,
+        canBeAppliedInBulk = false,
+        canBeAppliedToFile = false;
+
+  /// Initialize a newly created instance that converts the set literal to
+  /// a function body.
+  ConvertIntoBlockBody.setLiteral()
+      : _correctionKind = _CorrectionKind.setLiteral,
+        canBeAppliedInBulk = true,
+        canBeAppliedToFile = true;
+
   @override
   AssistKind get assistKind => DartAssistKind.CONVERT_INTO_BLOCK_BODY;
 
   @override
   FixKind get fixKind => DartFixKind.CONVERT_INTO_BLOCK_BODY;
 
+  @override
+  FixKind get multiFixKind => DartFixKind.CONVERT_INTO_BLOCK_BODY_MULTI;
+
   @override
   Future<void> compute(ChangeBuilder builder) async {
+    if (_correctionKind == _CorrectionKind.missingBody) {
+      await _computeMissingBody(builder);
+    } else {
+      await _computeSetLiteral(builder);
+    }
+  }
+
+  Future<void> _computeMissingBody(ChangeBuilder builder) async {
     final body = getEnclosingFunctionBody();
     if (body == null || body.isGenerator) return;
 
@@ -58,6 +92,57 @@ class ConvertIntoBlockBody extends ResolvedCorrectionProducer {
     });
   }
 
+  Future<void> _computeSetLiteral(ChangeBuilder builder) async {
+    var node = this.node;
+    if (node is! SetOrMapLiteral || !node.isSet) return;
+    var parent = node.parent;
+    if (parent is! ExpressionFunctionBody) return;
+    var functionDefinition = parent.functionDefinition;
+    var elements = node.elements;
+    await builder.addDartFileEdit(file, (builder) {
+      var next = functionDefinition.next!;
+      builder.addDeletion(
+          range.startStart(functionDefinition, next.precedingComments ?? next));
+
+      for (var element in elements) {
+        bool isCommaAdded;
+        if (element is IfElement) {
+          builder.addSimpleInsertion(element.thenElement.end, ';');
+          var elseElement = element.elseElement;
+          if (elseElement != null) {
+            builder.addSimpleInsertion(elseElement.end, ';');
+          }
+          isCommaAdded = true;
+        } else if (element is ForElement) {
+          builder.addSimpleInsertion(element.body.end, ';');
+          isCommaAdded = true;
+        } else {
+          isCommaAdded = false;
+        }
+        var endToken = element.endToken;
+        var next = endToken.next;
+        if (next?.type == TokenType.COMMA) {
+          builder.addSimpleReplacement(
+              range.token(next!), isCommaAdded ? '' : ';');
+        } else if (!isCommaAdded) {
+          builder.addSimpleInsertion(endToken.end, ';');
+        }
+      }
+
+      var semiColon = parent.semicolon;
+      if (semiColon != null) {
+        var precedingComments = semiColon.precedingComments;
+        var next = precedingComments?.next;
+        while (next is CommentToken) {
+          precedingComments = next;
+          next = next.next;
+        }
+        builder.addDeletion(
+            range.endEnd(precedingComments ?? semiColon.previous!, semiColon));
+      }
+    });
+  }
+
   List<String>? _getCodeForEmptyBody(EmptyFunctionBody body) {
     var functionElement = _getFunctionElement(body.parent);
     if (functionElement == null) return null;
@@ -106,3 +191,9 @@ class ConvertIntoBlockBody extends ResolvedCorrectionProducer {
     return null;
   }
 }
+
+/// The kinds of corrections supported by [ConvertIntoBlockBody].
+enum _CorrectionKind {
+  missingBody,
+  setLiteral,
+}

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

@@ -1,65 +0,0 @@
-// Copyright (c) 2023, 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.
-
-import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
-import 'package:analysis_server/src/services/correction/fix.dart';
-import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/ast/token.dart';
-import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
-import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
-import 'package:analyzer_plugin/utilities/range_factory.dart';
-
-class RemoveSetLiteral extends ResolvedCorrectionProducer {
-  @override
-  bool get canBeAppliedInBulk => true;
-
-  @override
-  bool get canBeAppliedToFile => true;
-
-  @override
-  FixKind get fixKind => DartFixKind.REMOVE_SET_LITERAL;
-
-  @override
-  FixKind get multiFixKind => DartFixKind.REMOVE_SET_LITERAL_MULTI;
-
-  @override
-  Future<void> compute(ChangeBuilder builder) async {
-    var node = this.node;
-    if (node is! SetOrMapLiteral) return;
-    var leftToken = node.leftBracket;
-    var rightBracket = node.rightBracket;
-    var rightStart = rightBracket.offset;
-    var rightEnd = rightBracket.next!.offset;
-
-    var elements = node.elements;
-    if (elements.isEmpty) return;
-    var first = elements.first;
-
-    var parent = node.parent?.parent?.parent;
-    if (parent is FunctionDeclaration) {
-      var nextToElement = first.endToken.next!;
-      if (nextToElement.type == TokenType.COMMA) {
-        rightStart = first.end;
-      }
-    } else {
-      var nextToElement = first.endToken.next!;
-      var nextToBracket = rightBracket.next!;
-      if (nextToElement.type == TokenType.COMMA) {
-        rightStart = nextToElement.end;
-        rightEnd = nextToBracket.offset;
-        if (nextToBracket.type == TokenType.COMMA) {
-          rightEnd = nextToBracket.next!.offset;
-        }
-      } else if (nextToBracket.type == TokenType.COMMA) {
-        rightStart = first.end;
-        rightEnd = nextToBracket.offset;
-      }
-    }
-
-    await builder.addDartFileEdit(file, (builder) {
-      builder.addDeletion(range.startStart(leftToken, leftToken.next!));
-      builder.addDeletion(range.startOffsetEndOffset(rightStart, rightEnd));
-    });
-  }
-}

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

@@ -402,6 +402,11 @@ class DartFixKind {
     DartFixKindPriority.DEFAULT,
     'Convert to block body',
   );
+  static const CONVERT_INTO_BLOCK_BODY_MULTI = FixKind(
+    'dart.fix.convert.bodyToBlock.multi',
+    DartFixKindPriority.IN_FILE,
+    'Convert to block body everywhere in file',
+  );
   static const CONVERT_FOR_EACH_TO_FOR_LOOP = FixKind(
     'dart.fix.convert.toForLoop',
     DartFixKindPriority.DEFAULT,
@@ -1278,16 +1283,6 @@ class DartFixKind {
     DartFixKindPriority.IN_FILE,
     'Remove invalid returned values in file',
   );
-  static const REMOVE_SET_LITERAL = FixKind(
-    'dart.fix.remove.setLiteral',
-    DartFixKindPriority.DEFAULT,
-    'Remove set literal',
-  );
-  static const REMOVE_SET_LITERAL_MULTI = FixKind(
-    'dart.fix.remove.setLiteral.multi',
-    DartFixKindPriority.IN_FILE,
-    'Remove set literal everywhere in file',
-  );
   static const REMOVE_THIS_EXPRESSION = FixKind(
     'dart.fix.remove.thisExpression',
     DartFixKindPriority.DEFAULT,

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

@@ -157,7 +157,6 @@ import 'package:analysis_server/src/services/correction/dart/remove_print.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_question_mark.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_required.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_returned_value.dart';
-import 'package:analysis_server/src/services/correction/dart/remove_set_literal.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_this_expression.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_to_list.dart';
 import 'package:analysis_server/src/services/correction/dart/remove_type_annotation.dart';
@@ -1048,7 +1047,7 @@ class FixProcessor extends BaseProcessor {
       CreateMixin.new,
     ],
     CompileTimeErrorCode.CONCRETE_CLASS_WITH_ABSTRACT_MEMBER: [
-      ConvertIntoBlockBody.new,
+      ConvertIntoBlockBody.missingBody,
       CreateNoSuchMethod.new,
       MakeClassAbstract.new,
     ],
@@ -1078,7 +1077,7 @@ class FixProcessor extends BaseProcessor {
       ReplaceEmptyMapPattern.empty,
     ],
     CompileTimeErrorCode.ENUM_WITH_ABSTRACT_MEMBER: [
-      ConvertIntoBlockBody.new,
+      ConvertIntoBlockBody.missingBody,
     ],
     CompileTimeErrorCode.EXTENDS_DISALLOWED_CLASS: [
       RemoveNameFromDeclarationClause.new,
@@ -1494,7 +1493,7 @@ class FixProcessor extends BaseProcessor {
       AddTypeAnnotation.new,
     ],
     ParserErrorCode.MISSING_FUNCTION_BODY: [
-      ConvertIntoBlockBody.new,
+      ConvertIntoBlockBody.missingBody,
     ],
     ParserErrorCode.MIXIN_DECLARES_CONSTRUCTOR: [
       RemoveConstructor.new,
@@ -1695,7 +1694,7 @@ class FixProcessor extends BaseProcessor {
       RemoveQuestionMark.new,
     ],
     WarningCode.UNNECESSARY_SET_LITERAL: [
-      RemoveSetLiteral.new,
+      ConvertIntoBlockBody.setLiteral,
     ],
     WarningCode.UNNECESSARY_TYPE_CHECK_FALSE: [
       RemoveComparison.typeCheck,

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

@@ -295,7 +295,8 @@ void f(List<int> list) {
   list.forEach((x) => {print(''), print('')});
 }
 ''');
-    await assertNoFix();
+    await assertNoFix(
+        errorFilter: (error) => error.errorCode.type == ErrorType.LINT);
   }
 
   Future<void> test_setLiteral_statement() async {
@@ -304,7 +305,8 @@ void f(List<int> list, bool b) {
   list.forEach((x) => {if (b) print('')});
 }
 ''');
-    await assertNoFix();
+    await assertNoFix(
+        errorFilter: (error) => error.errorCode.type == ErrorType.LINT);
   }
 
   Future<void> test_setLiteral_typeArguments() async {

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

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/src/services/correction/fix.dart';
+import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -10,12 +11,15 @@ import 'fix_processor.dart';
 
 void main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(ConvertIntoBlockBodyTest);
+    defineReflectiveTests(ConvertIntoBlockBodyMissingBodyTest);
+    defineReflectiveTests(ConvertIntoBlockBodySetLiteralBulkTest);
+    defineReflectiveTests(ConvertIntoBlockBodySetLiteralTest);
+    defineReflectiveTests(ConvertIntoBlockBodySetLiteralMultiTest);
   });
 }
 
 @reflectiveTest
-class ConvertIntoBlockBodyTest extends FixProcessorTest {
+class ConvertIntoBlockBodyMissingBodyTest extends FixProcessorTest {
   @override
   FixKind get kind => DartFixKind.CONVERT_INTO_BLOCK_BODY;
 
@@ -129,3 +133,218 @@ class A {
 ''');
   }
 }
+
+@reflectiveTest
+class ConvertIntoBlockBodySetLiteralBulkTest extends BulkFixProcessorTest {
+  Future<void> test_file() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+
+void f() {
+  g(() => {
+    g(() => {
+      1
+    })
+  });
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+
+void f() {
+  g(() {
+    g(() {
+      1;
+    });
+  });
+}
+''');
+  }
+}
+
+@reflectiveTest
+class ConvertIntoBlockBodySetLiteralMultiTest extends FixProcessorTest {
+  @override
+  FixKind get kind => DartFixKind.CONVERT_INTO_BLOCK_BODY_MULTI;
+
+  Future<void> test_multi() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+
+void f() {
+  g(() => {
+    g(() => {
+      1
+    })
+  });
+}
+''');
+    await assertHasFixAllFix(WarningCode.UNNECESSARY_SET_LITERAL, '''
+void g(void Function() fun) {}
+
+void f() {
+  g(() {
+    g(() {
+      1;
+    });
+  });
+}
+''');
+  }
+}
+
+@reflectiveTest
+class ConvertIntoBlockBodySetLiteralTest extends FixProcessorTest {
+  @override
+  FixKind get kind => DartFixKind.CONVERT_INTO_BLOCK_BODY;
+
+  Future<void> test_expressionFunctionBody() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => {1});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() {1;});
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comma_both() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => {1,},);
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() {1;},);
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comma_both_spaces() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => { 1 , } , );
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() { 1 ; } , );
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comma_inside() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => {1,});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() {1;});
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comma_outside() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => {1},);
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() {1;},);
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comment() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => /* hi */ {1});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() /* hi */ {1;});
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_multiple() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f(bool b) {
+  g(() => {1, if (b) 2, if (b) 3 else 4, for(;;) 5});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f(bool b) {
+  g(() {1; if (b) 2; if (b) 3; else 4; for(;;) 5;});
+}
+''');
+  }
+
+  Future<void> test_functionDeclaration() async {
+    await resolveTestCode('''
+void f() => {1};
+''');
+    await assertHasFix('''
+void f() {1;}
+''');
+  }
+
+  Future<void> test_functionDeclaration_comma() async {
+    await resolveTestCode('''
+void f() => {1,};
+''');
+    await assertHasFix('''
+void f() {1;}
+''');
+  }
+
+  Future<void> test_functionDeclaration_comma_spaces() async {
+    await resolveTestCode('''
+void f() => { 1 , } ;
+''');
+    await assertHasFix('''
+void f() { 1 ; }
+''');
+  }
+
+  Future<void> test_functionDeclaration_comments() async {
+    await resolveTestCode('''
+void f() => /* first */ {1} /* second */ /* third */ ;
+''');
+    await assertHasFix('''
+void f() /* first */ {1;} /* second */ /* third */
+''');
+  }
+
+  Future<void> test_functionDeclaration_multiple() async {
+    await resolveTestCode('''
+void f(bool b) => {for (;b;) 1, if (b) 2 else 3, if (b) 4,};
+''');
+    await assertHasFix('''
+void f(bool b) {for (;b;) 1; if (b) 2; else 3; if (b) 4;}
+''');
+  }
+}

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

@@ -11,14 +11,14 @@ import 'fix_processor.dart';
 
 void main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(RemoveSetLiteralBulkTest);
-    defineReflectiveTests(RemoveSetLiteralMultiTest);
-    defineReflectiveTests(RemoveSetLiteralTest);
+    defineReflectiveTests(ConvertToBlockFunctionBodyBulkTest);
+    defineReflectiveTests(ConvertToBlockFunctionBodyMultiTest);
+    defineReflectiveTests(ConvertToBlockFunctionBodyTest);
   });
 }
 
 @reflectiveTest
-class RemoveSetLiteralBulkTest extends BulkFixProcessorTest {
+class ConvertToBlockFunctionBodyBulkTest extends BulkFixProcessorTest {
   Future<void> test_file() async {
     await resolveTestCode('''
 void g(void Function() fun) {}
@@ -31,16 +31,16 @@ void f() {
 void g(void Function() fun) {}
 
 void f() {
-  g(() => g(() => 1));
+  g(() {g(() {1;});});
 }
 ''');
   }
 }
 
 @reflectiveTest
-class RemoveSetLiteralMultiTest extends FixProcessorTest {
+class ConvertToBlockFunctionBodyMultiTest extends FixProcessorTest {
   @override
-  FixKind get kind => DartFixKind.REMOVE_SET_LITERAL_MULTI;
+  FixKind get kind => DartFixKind.CONVERT_INTO_BLOCK_BODY_MULTI;
 
   Future<void> test_multi() async {
     await resolveTestCode('''
@@ -54,16 +54,16 @@ void f() {
 void g(void Function() fun) {}
 
 void f() {
-  g(() => g(() => 1));
+  g(() {g(() {1;});});
 }
 ''');
   }
 }
 
 @reflectiveTest
-class RemoveSetLiteralTest extends FixProcessorTest {
+class ConvertToBlockFunctionBodyTest extends FixProcessorTest {
   @override
-  FixKind get kind => DartFixKind.REMOVE_SET_LITERAL;
+  FixKind get kind => DartFixKind.CONVERT_INTO_BLOCK_BODY;
 
   Future<void> test_expressionFunctionBody() async {
     await resolveTestCode('''
@@ -75,7 +75,7 @@ void f() {
     await assertHasFix('''
 void g(void Function() fun) {}
 void f() {
-  g(() => 1);
+  g(() {1;});
 }
 ''');
   }
@@ -90,7 +90,7 @@ void f() {
     await assertHasFix('''
 void g(void Function() fun) {}
 void f() {
-  g(() => 1,);
+  g(() {1;},);
 }
 ''');
   }
@@ -105,7 +105,7 @@ void f() {
     await assertHasFix('''
 void g(void Function() fun) {}
 void f() {
-  g(() => 1 ,);
+  g(() { 1 ; } , );
 }
 ''');
   }
@@ -120,7 +120,7 @@ void f() {
     await assertHasFix('''
 void g(void Function() fun) {}
 void f() {
-  g(() => 1,);
+  g(() {1;});
 }
 ''');
   }
@@ -135,7 +135,37 @@ void f() {
     await assertHasFix('''
 void g(void Function() fun) {}
 void f() {
-  g(() => 1,);
+  g(() {1;},);
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_comment() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f() {
+  g(() => /* hi */ {1});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f() {
+  g(() /* hi */ {1;});
+}
+''');
+  }
+
+  Future<void> test_expressionFunctionBody_multiple() async {
+    await resolveTestCode('''
+void g(void Function() fun) {}
+void f(bool b) {
+  g(() => {1, if (b) 2, if (b) 3 else 4, for(;;) 5});
+}
+''');
+    await assertHasFix('''
+void g(void Function() fun) {}
+void f(bool b) {
+  g(() {1; if (b) 2; if (b) 3; else 4; for(;;) 5;});
 }
 ''');
   }
@@ -145,7 +175,7 @@ void f() {
 void f() => {1};
 ''');
     await assertHasFix('''
-void f() => 1;
+void f() {1;}
 ''');
   }
 
@@ -154,7 +184,7 @@ void f() => 1;
 void f() => {1,};
 ''');
     await assertHasFix('''
-void f() => 1;
+void f() {1;}
 ''');
   }
 
@@ -163,7 +193,25 @@ void f() => 1;
 void f() => { 1 , } ;
 ''');
     await assertHasFix('''
-void f() => 1;
+void f() { 1 ; }
+''');
+  }
+
+  Future<void> test_functionDeclaration_comments() async {
+    await resolveTestCode('''
+void f() => /* first */ {1} /* second */ /* third */ ;
+''');
+    await assertHasFix('''
+void f() /* first */ {1;} /* second */ /* third */
+''');
+  }
+
+  Future<void> test_functionDeclaration_multiple() async {
+    await resolveTestCode('''
+void f(bool b) => {for (;b;) 1, if (b) 2 else 3, if (b) 4,};
+''');
+    await assertHasFix('''
+void f(bool b) {for (;b;) 1; if (b) 2; else 3; if (b) 4;}
 ''');
   }
 }

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

@@ -66,6 +66,8 @@ import 'convert_into_block_body_test.dart' as convert_into_block_body;
 import 'convert_into_expression_body_test.dart' as convert_into_expression_body;
 import 'convert_into_is_not_test.dart' as convert_into_is_not;
 import 'convert_quotes_test.dart' as convert_quotes;
+import 'convert_to_block_function_body_test.dart'
+    as convert_to_block_function_body;
 import 'convert_to_boolean_expression_test.dart'
     as convert_to_boolean_expression;
 import 'convert_to_cascade_test.dart' as convert_to_cascade;
@@ -193,7 +195,6 @@ import 'remove_print_test.dart' as remove_print;
 import 'remove_question_mark_test.dart' as remove_question_mark;
 import 'remove_required_test.dart' as remove_required;
 import 'remove_returned_value_test.dart' as remove_returned_value;
-import 'remove_set_literal_test.dart' as remove_set_literal;
 import 'remove_this_expression_test.dart' as remove_this_expression;
 import 'remove_type_annotation_test.dart' as remove_type_annotation;
 import 'remove_type_arguments_test.dart' as remove_type_arguments;
@@ -336,6 +337,7 @@ void main() {
     convert_into_expression_body.main();
     convert_into_is_not.main();
     convert_quotes.main();
+    convert_to_block_function_body.main();
     convert_to_boolean_expression.main();
     convert_to_cascade.main();
     convert_to_constant_pattern.main();
@@ -446,7 +448,6 @@ void main() {
     remove_question_mark.main();
     remove_required.main();
     remove_returned_value.main();
-    remove_set_literal.main();
     remove_this_expression.main();
     remove_type_annotation.main();
     remove_type_arguments.main();

pkg/analyzer/lib/src/error/best_practices_verifier.dart

@@ -1383,11 +1383,8 @@ class BestPracticesVerifier extends RecursiveAstVisitor<void> {
       if (isReturnVoid) {
         var expression = body.expression;
         if (expression is SetOrMapLiteralImpl && expression.isSet) {
-          var elements = expression.elements;
-          if (elements.length == 1 && elements.first is Expression) {
-            _errorReporter.reportErrorForNode(
-                WarningCode.UNNECESSARY_SET_LITERAL, expression);
-          }
+          _errorReporter.reportErrorForNode(
+              WarningCode.UNNECESSARY_SET_LITERAL, expression);
         }
       }
     }

pkg/analyzer/test/src/diagnostics/unnecessary_set_literal_test.dart

@@ -116,13 +116,27 @@ void f() {
   }
 
   test_expressionFunctionBody_multipleElements() async {
-    await assertNoErrorsInCode(r'''
+    await assertErrorsInCode(r'''
 void g(void Function() fun) {}
 
 void f() {
   g(() => {1, 2});
 }
-''');
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 53, 6),
+    ]);
+  }
+
+  test_expressionFunctionBody_multipleElements_statements() async {
+    await assertErrorsInCode(r'''
+void g(void Function() fun) {}
+
+void f(bool b) {
+  g(() => {1, if (b) 2 else 3, 4, for (;;) 5},);
+}
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 59, 35),
+    ]);
   }
 
   test_expressionFunctionBody_object() async {
@@ -136,13 +150,15 @@ void f() {
   }
 
   test_expressionFunctionBody_statement() async {
-    await assertNoErrorsInCode(r'''
+    await assertErrorsInCode(r'''
 void g(void Function(bool) fun) {}
 
 void f() {
   g((value) => {if (value) print('')});
 }
-''');
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 62, 22),
+    ]);
   }
 
   test_expressionFunctionBody_void() async {
@@ -157,6 +173,16 @@ void f() {
     ]);
   }
 
+  test_expressionFunctionBody_void_empty() async {
+    await assertNoErrorsInCode(r'''
+void g(void Function() fun) {}
+
+void f() {
+  g(() => {});
+}
+''');
+  }
+
   test_functionDeclaration_dynamic() async {
     await assertNoErrorsInCode(r'''
 f() => {1};
@@ -216,9 +242,19 @@ void f() => {1: 2};
   }
 
   test_functionDeclaration_multipleElements() async {
-    await assertNoErrorsInCode(r'''
+    await assertErrorsInCode(r'''
 void f() => {1, 2};
-''');
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 12, 6),
+    ]);
+  }
+
+  test_functionDeclaration_multipleElements_statements() async {
+    await assertErrorsInCode(r'''
+void f(bool b) => {1, if (b) 2 else 3, 4, for (;;) 5};
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 18, 35),
+    ]);
   }
 
   test_functionDeclaration_object() async {
@@ -228,9 +264,11 @@ Object f() => {1};
   }
 
   test_functionDeclaration_statement() async {
-    await assertNoErrorsInCode(r'''
+    await assertErrorsInCode(r'''
 void f(bool value) => {if (value) print('')};
-''');
+''', [
+      error(WarningCode.UNNECESSARY_SET_LITERAL, 22, 22),
+    ]);
   }
 
   test_functionDeclaration_void() async {

pkg/compiler/tool/kernel_visitor/dart_html_metrics_visitor.dart

@@ -143,8 +143,9 @@ class MetricsVisitor extends RecursiveVisitor {
         var parentMethods = classInfo[parentName]!.methods.map((m) => m.name);
         var classMethods = classInfo[className]!.methods.map((m) => m.name);
 
-        parentMethods.forEach((method) =>
-            {if (!classMethods.contains(method)) notOverridden.add(method)});
+        parentMethods.forEach((method) {
+          if (!classMethods.contains(method)) notOverridden.add(method);
+        });
 
         // Update Method Info.
         classInfo[className]!.notOverriddenMethods = notOverridden;