fix constant_identifier_names pattern field over-reporting (#4298)

* fix `constant_identifier_names` pattern field over-reporting

* ++

Author: pq

lib/src/extensions.dart

@@ -21,6 +21,15 @@ class EnumLikeClassDescription {
   Map<DartObject, Set<FieldElement>> get enumConstants => {..._enumConstants};
 }
 
+extension AstNodeNullableExtension on AstNode? {
+  bool get isFieldNameShortcut {
+    var node = this;
+    if (node is NullCheckPattern) node = node.parent;
+    if (node is NullAssertPattern) node = node.parent;
+    return node is PatternField && node.name != null && node.name?.name == null;
+  }
+}
+
 extension AstNodeExtension on AstNode {
   Iterable<AstNode> get childNodes => childEntities.whereType<AstNode>();
 

lib/src/rules/constant_identifier_names.dart

@@ -7,6 +7,7 @@ import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 
 import '../analyzer.dart';
+import '../extensions.dart';
 import '../utils.dart';
 
 const _desc = r'Prefer using lowerCamelCase for constant names.';
@@ -84,6 +85,7 @@ class _Visitor extends SimpleAstVisitor<void> {
 
   @override
   void visitDeclaredVariablePattern(DeclaredVariablePattern node) {
+    if (node.parent.isFieldNameShortcut) return;
     checkIdentifier(node.name);
   }
 

lib/src/rules/no_leading_underscores_for_local_identifiers.dart

@@ -7,6 +7,7 @@ import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 
 import '../analyzer.dart';
+import '../extensions.dart';
 import '../util/ascii_utils.dart';
 
 const _desc = r'Avoid leading underscores for local identifiers.';
@@ -146,12 +147,3 @@ class _Visitor extends SimpleAstVisitor<void> {
     }
   }
 }
-
-extension on AstNode? {
-  bool get isFieldNameShortcut {
-    var node = this;
-    if (node is NullCheckPattern) node = node.parent;
-    if (node is NullAssertPattern) node = node.parent;
-    return node is PatternField && node.name != null && node.name?.name == null;
-  }
-}

test/rules/constant_identifier_names_test.dart

@@ -45,13 +45,71 @@ void f() {
       lint(20, 2),
     ]);
   }
+
+  test_destructuredObjectField_switch() async {
+    await assertDiagnostics(r'''
+class A {
+  var a;
+}
+
+f(A a) {
+  switch (a) {
+    case A(a: int a_b):
+  }
+  switch (a) {
+    case A(a: int a_b?):
+    case A(a: int a_b!):
+  }
+}
+''', [
+      lint(64, 3),
+      lint(107, 3),
+      lint(132, 3),
+    ]);
+  }
+
+  test_destructuredObjectField_switch_ok() async {
+    await assertNoDiagnostics(r'''
+class A {
+  var a_b;
+}
+
+f(A a) {
+  switch (a) {
+    case A(:var a_b):
+  }
+  switch (a) {
+    case A(:var a_b?):
+    case A(:var a_b!): 
+  }
+}
+''');
+  }
 }
 
 @reflectiveTest
 class ConstantIdentifierNamesRecordsTest extends LintRuleTest {
   @override
   String get lintRule => 'constant_identifier_names';
 
+  test_recordFieldDestructured() async {
+    await assertDiagnostics(r'''
+f(Object o) {
+  if (o case (x: int x_x, z: int z)) { }
+}
+''', [
+      lint(35, 3),
+    ]);
+  }
+
+  test_recordFieldDestructured_ok() async {
+    await assertNoDiagnostics(r'''
+f(Object o) {
+  if (o case (x_y: int x, z: int z)) { }
+}
+''');
+  }
+
   test_recordTypeDeclarations() async {
     await assertDiagnostics(r'''
 const RR = (x: 1);