From ecdbbc603c27be903d8822bbd9ddf3a94e6c7ce5 Mon Sep 17 00:00:00 2001
From: pq <pquitslund@gmail.com>
Date: Wed, 1 Sep 2021 11:09:12 -0700
Subject: [PATCH 1/3] + unnecessary_constructor_name

---
 lib/src/rules.dart                            |  2 +
 .../rules/unnecessary_constructor_name.dart   | 78 +++++++++++++++++++
 .../rules/unnecessary_constructor_name.dart   | 15 ++++
 3 files changed, 95 insertions(+)
 create mode 100644 lib/src/rules/unnecessary_constructor_name.dart
 create mode 100644 test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart

diff --git a/lib/src/rules.dart b/lib/src/rules.dart
index af930d83e..3d2c501cf 100644
--- a/lib/src/rules.dart
+++ b/lib/src/rules.dart
@@ -164,6 +164,7 @@ import 'rules/unawaited_futures.dart';
 import 'rules/unnecessary_await_in_return.dart';
 import 'rules/unnecessary_brace_in_string_interps.dart';
 import 'rules/unnecessary_const.dart';
+import 'rules/unnecessary_constructor_name.dart';
 import 'rules/unnecessary_final.dart';
 import 'rules/unnecessary_getters_setters.dart';
 import 'rules/unnecessary_lambdas.dart';
@@ -362,6 +363,7 @@ void registerLintRules({bool inTestMode = false}) {
     ..register(UnnecessaryAwaitInReturn())
     ..register(UnnecessaryBraceInStringInterps())
     ..register(UnnecessaryConst())
+    ..register(UnnecessaryConstructorName())
     ..register(UnnecessaryFinal())
     ..register(UnnecessaryNew())
     ..register(UnnecessaryNullAwareAssignments())
diff --git a/lib/src/rules/unnecessary_constructor_name.dart b/lib/src/rules/unnecessary_constructor_name.dart
new file mode 100644
index 000000000..d381a9f77
--- /dev/null
+++ b/lib/src/rules/unnecessary_constructor_name.dart
@@ -0,0 +1,78 @@
+// Copyright (c) 2021, 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:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/visitor.dart';
+
+import '../analyzer.dart';
+
+const _desc = r'Unnecessary `.new` constructor name.';
+
+const _details = r'''
+**PREFER** using the default unnamed Constructor over `.new`.
+
+Given a class `C`, the named unnamed constructor `C.new` refers to the same
+constructor as the unnamed `C`. As such it adds nothing but visual noise to
+invocations and should be avoided (unless being used to identify a constructor
+tear-off).
+
+**BAD:**
+```dart
+class A {
+  A.new(); // LINT
+}
+
+var a = A.new(); // LINT
+```
+
+**GOOD:**
+```dart
+class A {
+  A.ok();
+}
+
+var a = A();
+var aa = A.ok();
+var makeA = A.new;
+```
+''';
+
+class UnnecessaryConstructorName extends LintRule {
+  UnnecessaryConstructorName()
+      : super(
+            name: 'unnecessary_constructor_name',
+            description: _desc,
+            details: _details,
+            group: Group.style);
+
+  @override
+  void registerNodeProcessors(
+      NodeLintRegistry registry, LinterContext context) {
+    var visitor = _Visitor(this);
+    registry.addConstructorDeclaration(this, visitor);
+    registry.addInstanceCreationExpression(this, visitor);
+  }
+}
+
+class _Visitor extends SimpleAstVisitor {
+  final LintRule rule;
+
+  _Visitor(this.rule);
+
+  @override
+  void visitConstructorDeclaration(ConstructorDeclaration node) {
+    _check(node.name);
+  }
+
+  @override
+  void visitInstanceCreationExpression(InstanceCreationExpression node) {
+    _check(node.constructorName.name);
+  }
+
+  void _check(SimpleIdentifier? name) {
+    if (name?.name == 'new') {
+      rule.reportLint(name);
+    }
+  }
+}
diff --git a/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart b/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart
new file mode 100644
index 000000000..71d3c31c5
--- /dev/null
+++ b/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart
@@ -0,0 +1,15 @@
+// Copyright (c) 2021, 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.
+
+// test w/ `dart test -N unnecessary_constructor_name`
+
+class A {
+  A.new(); // LINT
+  A.ok(); // OK
+}
+
+var a = A.new(); // LINT
+var aa = A(); // OK
+var aaa = A.ok(); // OK
+var makeA = A.new; // OK
\ No newline at end of file

From ba13dad622d4dd2fe6e742d528886b0d19d84b3f Mon Sep 17 00:00:00 2001
From: pq <pquitslund@gmail.com>
Date: Wed, 1 Sep 2021 11:10:42 -0700
Subject: [PATCH 2/3] + newline

---
 .../rules/unnecessary_constructor_name.dart                     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart b/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart
index 71d3c31c5..3f4c4f2f1 100644
--- a/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart
+++ b/test_data/rules/experiments/constructor_tearoffs/rules/unnecessary_constructor_name.dart
@@ -12,4 +12,4 @@ class A {
 var a = A.new(); // LINT
 var aa = A(); // OK
 var aaa = A.ok(); // OK
-var makeA = A.new; // OK
\ No newline at end of file
+var makeA = A.new; // OK

From 167483bb3a0d835bedcbb82146128a9ba52896bb Mon Sep 17 00:00:00 2001
From: pq <pquitslund@gmail.com>
Date: Wed, 1 Sep 2021 11:19:05 -0700
Subject: [PATCH 3/3] + unnecessary_constructor_name

---
 example/all.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/example/all.yaml b/example/all.yaml
index f8741cd7f..cb31d15bb 100644
--- a/example/all.yaml
+++ b/example/all.yaml
@@ -160,6 +160,7 @@ linter:
     - unnecessary_await_in_return
     - unnecessary_brace_in_string_interps
     - unnecessary_const
+    - unnecessary_constructor_name
     - unnecessary_final
     - unnecessary_getters_setters
     - unnecessary_lambdas