[DAS] Adds fix to use_if_null_to_convert_nulls_to_bools

Fixes: #47436
Change-Id: Idcdca7389a771d8ecee5c4746a37324cc5d96261
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/421889
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Auto-Submit: Felipe Morschel <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>

Author: FMorschel

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

@@ -12,7 +12,14 @@ import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:analyzer_plugin/utilities/range_factory.dart';
 
 class ConvertToIfNull extends ResolvedCorrectionProducer {
-  ConvertToIfNull({required super.context});
+  /// Identifies the case to be fixed.
+  final _FixCase _fixCase;
+
+  ConvertToIfNull.preferIfNull({required super.context})
+    : _fixCase = _FixCase.preferIfNull;
+
+  ConvertToIfNull.useToConvertNullsToBools({required super.context})
+    : _fixCase = _FixCase.useToConvertNullsToBools;
 
   @override
   CorrectionApplicability get applicability =>
@@ -26,6 +33,15 @@ class ConvertToIfNull extends ResolvedCorrectionProducer {
 
   @override
   Future<void> compute(ChangeBuilder builder) async {
+    switch (_fixCase) {
+      case _FixCase.preferIfNull:
+        await _preferIfNull(builder);
+      case _FixCase.useToConvertNullsToBools:
+        await _useToConvertNullsToBools(builder);
+    }
+  }
+
+  Future<void> _preferIfNull(ChangeBuilder builder) async {
     var node = this.node;
     if (node is ConditionalExpression &&
         node.offset == errorOffset &&
@@ -67,4 +83,37 @@ class ConvertToIfNull extends ResolvedCorrectionProducer {
       });
     }
   }
+
+  Future<void> _useToConvertNullsToBools(ChangeBuilder builder) async {
+    var node = this.node;
+    if (node is BinaryExpression &&
+        node.offset == errorOffset &&
+        node.length == errorLength &&
+        (node.operator.type == TokenType.EQ_EQ ||
+            node.operator.type == TokenType.BANG_EQ)) {
+      var left = node.leftOperand;
+      var right = node.rightOperand;
+      Expression nullableExpression;
+      if (left is! BooleanLiteral) {
+        nullableExpression = left;
+      } else if (right is! BooleanLiteral) {
+        nullableExpression = right;
+      } else {
+        return;
+      }
+      await builder.addDartFileEdit(file, (builder) {
+        builder.addReplacement(range.node(node), (builder) {
+          builder.write(utils.getNodeText(nullableExpression));
+          builder.write(' ${TokenType.QUESTION_QUESTION.lexeme} ');
+          if (node.operator.type == TokenType.EQ_EQ) {
+            builder.write('false');
+          } else {
+            builder.write('true');
+          }
+        });
+      });
+    }
+  }
 }
+
+enum _FixCase { preferIfNull, useToConvertNullsToBools }

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -2515,7 +2515,7 @@ LintCode.use_full_hex_values_for_flutter_colors:
 LintCode.use_function_type_syntax_for_parameters:
   status: hasFix
 LintCode.use_if_null_to_convert_nulls_to_bools:
-  status: needsFix
+  status: hasFix
 LintCode.use_is_even_rather_than_modulo:
   status: needsFix
 LintCode.use_key_in_widget_constructors:

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

@@ -434,7 +434,7 @@ final _builtInLintGenerators = <LintCode, List<ProducerGenerator>>{
   LinterLintCode.prefer_if_elements_to_conditional_expressions: [
     ConvertConditionalExpressionToIfElement.new,
   ],
-  LinterLintCode.prefer_if_null_operators: [ConvertToIfNull.new],
+  LinterLintCode.prefer_if_null_operators: [ConvertToIfNull.preferIfNull],
   LinterLintCode.prefer_initializing_formals: [ConvertToInitializingFormal.new],
   LinterLintCode.prefer_inlined_adds_single: [
     ConvertAddAllToSpread.new,
@@ -539,6 +539,9 @@ final _builtInLintGenerators = <LintCode, List<ProducerGenerator>>{
   LinterLintCode.use_function_type_syntax_for_parameters: [
     ConvertToGenericFunctionSyntax.new,
   ],
+  LinterLintCode.use_if_null_to_convert_nulls_to_bools: [
+    ConvertToIfNull.useToConvertNullsToBools,
+  ],
   LinterLintCode.use_key_in_widget_constructors: [AddKeyToConstructors.new],
   LinterLintCode.use_named_constants: [ReplaceWithNamedConstant.new],
   LinterLintCode.use_null_aware_elements: [

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

@@ -12,13 +12,15 @@ import 'fix_processor.dart';
 
 void main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(ConvertToIfNullBulkTest);
-    defineReflectiveTests(ConvertToIfNullTest);
+    defineReflectiveTests(ConvertToIfNullPreferBulkTest);
+    defineReflectiveTests(ConvertToIfNullPreferTest);
+    defineReflectiveTests(ConvertToIfNullUseBulkTest);
+    defineReflectiveTests(ConvertToIfNullUseTest);
   });
 }
 
 @reflectiveTest
-class ConvertToIfNullBulkTest extends BulkFixProcessorTest {
+class ConvertToIfNullPreferBulkTest extends BulkFixProcessorTest {
   @override
   String get lintCode => LintNames.prefer_if_null_operators;
 
@@ -39,7 +41,7 @@ void f(String s) {
 }
 
 @reflectiveTest
-class ConvertToIfNullTest extends FixProcessorLintTest {
+class ConvertToIfNullPreferTest extends FixProcessorLintTest {
   @override
   FixKind get kind => DartFixKind.CONVERT_TO_IF_NULL;
 
@@ -133,3 +135,59 @@ void f(String? s) {
 ''');
   }
 }
+
+@reflectiveTest
+class ConvertToIfNullUseBulkTest extends BulkFixProcessorTest {
+  @override
+  String get lintCode => LintNames.use_if_null_to_convert_nulls_to_bools;
+
+  Future<void> test_singleFile() async {
+    await resolveTestCode('''
+void f(bool? value) {
+  print(value == true);
+  print(value != false);
+}
+''');
+    await assertHasFix('''
+void f(bool? value) {
+  print(value ?? false);
+  print(value ?? true);
+}
+''');
+  }
+}
+
+@reflectiveTest
+class ConvertToIfNullUseTest extends FixProcessorLintTest {
+  @override
+  FixKind get kind => DartFixKind.CONVERT_TO_IF_NULL;
+
+  @override
+  String get lintCode => LintNames.use_if_null_to_convert_nulls_to_bools;
+
+  Future<void> test_different_false() async {
+    await resolveTestCode('''
+void f(bool? value) {
+  print(value != false);
+}
+''');
+    await assertHasFix('''
+void f(bool? value) {
+  print(value ?? true);
+}
+''');
+  }
+
+  Future<void> test_equals_true() async {
+    await resolveTestCode('''
+void f(bool? value) {
+  print(value == true);
+}
+''');
+    await assertHasFix('''
+void f(bool? value) {
+  print(value ?? false);
+}
+''');
+  }
+}