From eb00fb4bb9edbd761b3d6fb6a6a20dead1a52e74 Mon Sep 17 00:00:00 2001
From: solid-vovabeloded <41615621+solid-vovabeloded@users.noreply.github.com>
Date: Wed, 15 Nov 2023 18:49:46 +0200
Subject: [PATCH] Allow magic numbers for default values (#72)

* Allow magic numbers for default values

* More tests

---------

Co-authored-by: vladimir-beloded <x-volodymyr.beloded@transcarent.com>
---
 .../no_magic_number/no_magic_number_rule.dart |  7 ++++-
 lint_test/no_magic_number_test.dart           | 28 +++++++++++++++++--
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/lib/lints/no_magic_number/no_magic_number_rule.dart b/lib/lints/no_magic_number/no_magic_number_rule.dart
index c9e1e201..6f282425 100644
--- a/lib/lints/no_magic_number/no_magic_number_rule.dart
+++ b/lib/lints/no_magic_number/no_magic_number_rule.dart
@@ -69,7 +69,8 @@ class NoMagicNumberRule extends SolidLintRule<NoMagicNumberParameters> {
           .where(_isNotInsideConstConstructor)
           .where(_isNotInDateTime)
           .where(_isNotInsideIndexExpression)
-          .where(_isNotInsideEnumConstantArguments);
+          .where(_isNotInsideEnumConstantArguments)
+          .where(_isNotDefaultValue);
 
       for (final magicNumber in magicNumbers) {
         reporter.reportErrorForNode(code, magicNumber);
@@ -122,4 +123,8 @@ class NoMagicNumberRule extends SolidLintRule<NoMagicNumberParameters> {
       null;
 
   bool _isNotInsideIndexExpression(Literal l) => l.parent is! IndexExpression;
+
+  bool _isNotDefaultValue(Literal literal) {
+    return literal.thisOrAncestorOfType<DefaultFormalParameter>() == null;
+  }
 }
diff --git a/lint_test/no_magic_number_test.dart b/lint_test/no_magic_number_test.dart
index b215ec4b..239564a5 100644
--- a/lint_test/no_magic_number_test.dart
+++ b/lint_test/no_magic_number_test.dart
@@ -1,4 +1,7 @@
-// ignore_for_file: unused_local_variable, prefer_match_file_name
+// ignore_for_file: unused_local_variable
+// ignore_for_file: prefer_match_file_name
+// ignore_for_file: avoid_unused_parameters
+// ignore_for_file: no_empty_block
 
 /// Check the `no_magic_number` rule
 
@@ -52,6 +55,27 @@ void fun() {
   // Allowed in indexed expression
   final result = list[1];
 
-  // Allowed in DateTime because it doesn't have cons constructor
+  // Allowed in DateTime because it doesn't have const constructor
   final apocalypse = DateTime(2012, 12, 21);
 }
+
+// Allowed for defaults in constructors and methods.
+class DefaultValues {
+  final int value;
+
+  DefaultValues.named({
+    this.value = 2,
+  });
+
+  DefaultValues.positional([
+    this.value = 3,
+  ]);
+
+  void methodWithNamedParam({int value = 4}) {}
+
+  void methodWithPositionalParam([int value = 5]) {}
+}
+
+void topLevelFunctionWithDefaultParam({int value = 6}) {
+  ({int value = 7}) {};
+}