lint rule: Remove the avoid_null_checks_in_equality_operators rule

Fixes https://github.com/dart-lang/linter/issues/5063

Change-Id: I85a3c9e1a568d55ce1e21d0f1fee4ce1c83292f4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/389300
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>

Author: srawlins

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

@@ -12,7 +12,6 @@ import 'package:analyzer/src/error/codes.g.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';
-import 'package:linter/src/lint_codes.dart';
 
 class RemoveComparison extends ResolvedCorrectionProducer {
   @override
@@ -51,8 +50,7 @@ class RemoveComparison extends ResolvedCorrectionProducer {
     return errorCode == WarningCode.UNNECESSARY_NAN_COMPARISON_TRUE ||
         errorCode == WarningCode.UNNECESSARY_NULL_COMPARISON_ALWAYS_NULL_TRUE ||
         errorCode == WarningCode.UNNECESSARY_NULL_COMPARISON_NEVER_NULL_TRUE ||
-        errorCode == WarningCode.UNNECESSARY_TYPE_CHECK_TRUE ||
-        errorCode == LinterLintCode.avoid_null_checks_in_equality_operators;
+        errorCode == WarningCode.UNNECESSARY_TYPE_CHECK_TRUE;
   }
 
   @override

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

@@ -1923,8 +1923,6 @@ LintCode.avoid_js_rounded_ints:
   status: noFix
 LintCode.avoid_multiple_declarations_per_line:
   status: hasFix
-LintCode.avoid_null_checks_in_equality_operators:
-  status: hasFix
 LintCode.avoid_positional_boolean_parameters:
   status: noFix
   notes: |-

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

@@ -313,9 +313,6 @@ final _builtInLintProducers = <LintCode, List<ProducerGenerator>>{
   LinterLintCode.avoid_multiple_declarations_per_line: [
     SplitMultipleDeclarations.new,
   ],
-  LinterLintCode.avoid_null_checks_in_equality_operators: [
-    RemoveComparison.new,
-  ],
   LinterLintCode.avoid_print: [
     MakeConditionalOnDebugMode.new,
     RemovePrint.new,

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

@@ -12,10 +12,10 @@ import 'fix_processor.dart';
 void main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(RemoveComparisonTest);
-    defineReflectiveTests(RemoveTypeCheckTest);
-    defineReflectiveTests(RemoveTypeCheckBulkTest);
-    defineReflectiveTests(RemoveNullCheckComparisonTest);
     defineReflectiveTests(RemoveNullCheckComparisonBulkTest);
+    defineReflectiveTests(RemoveNullCheckComparisonTest);
+    defineReflectiveTests(RemoveTypeCheckBulkTest);
+    defineReflectiveTests(RemoveTypeCheckTest);
   });
 }
 
@@ -610,7 +610,7 @@ class Person {
   final String name = '';
 
   @override
-  operator ==(Object? other) =>
+  operator ==(Object other) =>
           other != null &&
           other is Person &&
           name == other.name;
@@ -620,7 +620,7 @@ class Person2 {
   final String name = '';
 
   @override
-  operator ==(Object? other) =>
+  operator ==(Object other) =>
           other != null &&
           other is Person &&
           name == other.name;
@@ -631,7 +631,7 @@ class Person {
   final String name = '';
 
   @override
-  operator ==(Object? other) =>
+  operator ==(Object other) =>
           other is Person &&
           name == other.name;
 }
@@ -640,7 +640,7 @@ class Person2 {
   final String name = '';
 
   @override
-  operator ==(Object? other) =>
+  operator ==(Object other) =>
           other is Person &&
           name == other.name;
 }

pkg/linter/example/all.yaml

@@ -27,7 +27,6 @@ linter:
     - avoid_init_to_null
     - avoid_js_rounded_ints
     - avoid_multiple_declarations_per_line
-    - avoid_null_checks_in_equality_operators
     - avoid_positional_boolean_parameters
     - avoid_print
     - avoid_private_typedef_functions

pkg/linter/lib/src/lint_codes.g.dart

@@ -240,13 +240,6 @@ class LinterLintCode extends LintCode {
         "Try splitting the variable declarations into multiple lines.",
   );
 
-  static const LintCode avoid_null_checks_in_equality_operators =
-      LinterLintCode(
-    LintNames.avoid_null_checks_in_equality_operators,
-    "Unnecessary null comparison in implementation of '=='.",
-    correctionMessage: "Try removing the comparison.",
-  );
-
   static const LintCode avoid_positional_boolean_parameters = LinterLintCode(
     LintNames.avoid_positional_boolean_parameters,
     "'bool' parameters should be named parameters.",

pkg/linter/lib/src/rules/avoid_null_checks_in_equality_operators.dart

@@ -2,113 +2,19 @@
 // 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:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/ast/token.dart';
-import 'package:analyzer/dart/ast/visitor.dart';
-import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/nullability_suffix.dart';
+import 'package:pub_semver/pub_semver.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 
 const _desc = r"Don't check for `null` in custom `==` operators.";
 
-bool _isComparingEquality(TokenType tokenType) =>
-    tokenType == TokenType.BANG_EQ || tokenType == TokenType.EQ_EQ;
-
-bool _isComparingParameterWithNull(BinaryExpression node, Element? parameter) =>
-    _isComparingEquality(node.operator.type) &&
-    ((node.leftOperand.isNullLiteral &&
-            _isParameter(node.rightOperand, parameter)) ||
-        (node.rightOperand.isNullLiteral &&
-            _isParameter(node.leftOperand, parameter)));
-
-bool _isParameter(Expression expression, Element? parameter) =>
-    expression.canonicalElement == parameter;
-
-bool _isParameterWithQuestionQuestion(
-        BinaryExpression node, Element? parameter) =>
-    node.operator.type == TokenType.QUESTION_QUESTION &&
-    _isParameter(node.leftOperand, parameter);
-
 class AvoidNullChecksInEqualityOperators extends LintRule {
   AvoidNullChecksInEqualityOperators()
       : super(
-          name: LintNames.avoid_null_checks_in_equality_operators,
-          description: _desc,
-        );
-
-  @override
-  LintCode get lintCode =>
-      LinterLintCode.avoid_null_checks_in_equality_operators;
-
-  @override
-  void registerNodeProcessors(
-      NodeLintRegistry registry, LinterContext context) {
-    var visitor = _Visitor(this);
-    registry.addMethodDeclaration(this, visitor);
-  }
-}
-
-class _BodyVisitor extends RecursiveAstVisitor<void> {
-  final Element? parameter;
-  final LintRule rule;
-
-  _BodyVisitor(this.parameter, this.rule);
-
-  @override
-  visitBinaryExpression(BinaryExpression node) {
-    if (_isParameterWithQuestionQuestion(node, parameter) ||
-        _isComparingParameterWithNull(node, parameter)) {
-      rule.reportLint(node);
-    }
-    super.visitBinaryExpression(node);
-  }
-
-  @override
-  visitMethodInvocation(MethodInvocation node) {
-    if (node.operator?.type == TokenType.QUESTION_PERIOD &&
-        node.target.canonicalElement == parameter) {
-      rule.reportLint(node);
-    }
-    super.visitMethodInvocation(node);
-  }
-
-  @override
-  visitPropertyAccess(PropertyAccess node) {
-    if (node.operator.type == TokenType.QUESTION_PERIOD &&
-        node.target.canonicalElement == parameter) {
-      rule.reportLint(node);
-    }
-    super.visitPropertyAccess(node);
-  }
-}
-
-class _Visitor extends SimpleAstVisitor<void> {
-  final LintRule rule;
-
-  _Visitor(this.rule);
+            name: LintNames.avoid_null_checks_in_equality_operators,
+            description: _desc,
+            state: State.removed(since: Version(3, 7, 0)));
 
   @override
-  void visitMethodDeclaration(MethodDeclaration node) {
-    var parameters = node.parameters?.parameters;
-    if (parameters == null) {
-      return;
-    }
-
-    if (node.name.type != TokenType.EQ_EQ || parameters.length != 1) {
-      return;
-    }
-
-    var parameter = parameters.first.declaredElement?.canonicalElement;
-
-    // Analyzer will produce UNNECESSARY_NULL_COMPARISON_FALSE|TRUE
-    // See: https://github.com/dart-lang/linter/issues/2864
-    if (parameter is VariableElement &&
-        parameter.type.nullabilitySuffix != NullabilitySuffix.question) {
-      return;
-    }
-
-    node.body.accept(_BodyVisitor(parameter, rule));
-  }
+  LintCode get lintCode => LinterLintCode.removed_lint;
 }

pkg/linter/messages.yaml

@@ -1455,6 +1455,7 @@ LintCode:
     addedIn: "2.0"
     categories: [style]
     hasPublishedDocs: false
+    removedIn: "3.7"
     deprecatedDetails: |-
       **DON'T** check for `null` in custom `==` operators.
 
@@ -1482,6 +1483,8 @@ LintCode:
         operator ==(Object? other) => other is Person && name == other.name;
       }
       ```
+
+      This rule has been removed.
   avoid_positional_boolean_parameters:
     problemMessage: "'bool' parameters should be named parameters."
     correctionMessage: "Try converting the parameter to a named parameter."

pkg/linter/test/rules/all.dart

@@ -43,8 +43,6 @@ import 'avoid_init_to_null_test.dart' as avoid_init_to_null;
 import 'avoid_js_rounded_ints_test.dart' as avoid_js_rounded_ints;
 import 'avoid_multiple_declarations_per_line_test.dart'
     as avoid_multiple_declarations_per_line;
-import 'avoid_null_checks_in_equality_operators_test.dart'
-    as avoid_null_checks_in_equality_operators;
 import 'avoid_positional_boolean_parameters_test.dart'
     as avoid_positional_boolean_parameters;
 import 'avoid_print_test.dart' as avoid_print;
@@ -346,7 +344,6 @@ void main() {
   avoid_init_to_null.main();
   avoid_js_rounded_ints.main();
   avoid_multiple_declarations_per_line.main();
-  avoid_null_checks_in_equality_operators.main();
   avoid_positional_boolean_parameters.main();
   avoid_print.main();
   avoid_private_typedef_functions.main();