fix: ignore enum constant arguments for no-magic-number (#1150)

* fix: ignore enum constant arguments for no-magic-number

* docs: update changelog

* test: fix test example

Author: nxtSwitch

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+* fix: ignore enum constant arguments for [`no-magic-number`](https://dartcodemetrics.dev/docs/rules/common/no-magic-number).
 * fix: correctly handle prefixed enums and static instance fields for [`prefer-moving-to-variable`](https://dartcodemetrics.dev/docs/rules/common/prefer-moving-to-variable).
 * feat: add static code diagnostic [`prefer-provide-intl-description`](https://dartcodemetrics.dev/docs/rules/intl/prefer-provide-intl-description).
 * feat: exclude `.freezed.dart` files by default.

lib/src/analyzers/lint_analyzer/rules/rules_list/no_magic_number/no_magic_number_rule.dart

@@ -53,6 +53,7 @@ class NoMagicNumberRule extends CommonRule {
         .where(_isNotInsideConstConstructor)
         .where(_isNotInDateTime)
         .where(_isNotInsideIndexExpression)
+        .where(_isNotInsideEnumConstantArguments)
         .map((lit) => createIssue(
               rule: this,
               location: nodeLocation(node: lit, source: source),
@@ -80,6 +81,14 @@ class NoMagicNumberRule extends CommonRule {
       ) ==
       null;
 
+  bool _isNotInsideEnumConstantArguments(Literal l) {
+    final node = l.thisOrAncestorMatching(
+      (ancestor) => ancestor is EnumConstantArguments,
+    );
+
+    return node == null;
+  }
+
   bool _isNotInsideCollectionLiteral(Literal l) => l.parent is! TypedLiteral;
 
   bool _isNotInsideConstMap(Literal l) {

test/src/analyzers/lint_analyzer/rules/rules_list/no_magic_number/examples/enum_example.dart

@@ -0,0 +1,17 @@
+enum ExampleMagicNumbers {
+  second(2),
+  third(3);
+
+  final int value;
+
+  const ExampleMagicNumbers(this.value);
+}
+
+enum ExampleNamedMagicNumbers {
+  second(value: 2),
+  third(value: 3);
+
+  final int value;
+
+  const ExampleNamedMagicNumbers({required this.value});
+}

test/src/analyzers/lint_analyzer/rules/rules_list/no_magic_number/no_magic_number_rule_test.dart

@@ -9,6 +9,7 @@ const _incorrectExamplePath = 'no_magic_number/examples/incorrect_example.dart';
 const _exceptionsExamplePath =
     'no_magic_number/examples/exceptions_example.dart';
 const _arrayExamplePath = 'no_magic_number/examples/array_example.dart';
+const _enumExamplePath = 'no_magic_number/examples/enum_example.dart';
 
 void main() {
   group('NoMagicNumberRule', () {
@@ -42,6 +43,13 @@ void main() {
       RuleTestHelper.verifyNoIssues(issues);
     });
 
+    test("doesn't report enum arguments", () async {
+      final unit = await RuleTestHelper.resolveFromFile(_enumExamplePath);
+      final issues = NoMagicNumberRule().check(unit);
+
+      RuleTestHelper.verifyNoIssues(issues);
+    });
+
     test("doesn't report exceptional code", () async {
       final unit = await RuleTestHelper.resolveFromFile(_exceptionsExamplePath);
       final issues = NoMagicNumberRule().check(unit);