Fix: Resolve ListParam equality issue for caching identical requests

dio/CHANGELOG.md

@@ -9,6 +9,7 @@ See the [Migration Guide][] for the complete breaking changes list.**
 - Removes redundant warnings when composing request options on Web.
 - Fixes boundary inconsistency in `FormData.clone()`.
 - Support `FileAccessMode` in `Dio.download` and `Dio.downloadUri` to change download file opening mode
+- Fix `ListParam` equality by using the `DeepCollectionEquality`.
 
 ## 5.7.0
 

dio/lib/src/parameter.dart

@@ -1,3 +1,5 @@
+import 'package:collection/collection.dart';
+
 import 'options.dart';
 
 /// Indicates a param being used as queries or form data,
@@ -26,9 +28,12 @@ class ListParam<T> {
       identical(this, other) ||
       other is ListParam &&
           runtimeType == other.runtimeType &&
-          value == other.value &&
+          const DeepCollectionEquality().equals(value, other.value) &&
           format == other.format;
 
   @override
-  int get hashCode => value.hashCode ^ format.hashCode;
+  int get hashCode => Object.hash(
+        const DeepCollectionEquality().hash(value),
+        format,
+      );
 }

dio/pubspec.yaml

@@ -21,6 +21,7 @@ environment:
 
 dependencies:
   async: ^2.8.2
+  collection: ^1.16.0
   http_parser: ^4.0.0
   meta: ^1.5.0
   path: ^1.8.0

dio/test/parameter_test.dart

@@ -0,0 +1,32 @@
+import 'package:dio/dio.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('ListParam equality for Map key', () {
+    final param1 = const ListParam(['item1', 'item2'], ListFormat.csv);
+    final param2 = const ListParam(['item1', 'item2'], ListFormat.csv);
+    final param3 = const ListParam(['item3', 'item4'], ListFormat.csv);
+    final param4 = const ListParam(['item2', 'item1'], ListFormat.csv);
+
+    final cache = {param1: 'Cached Response'};
+
+    expect(
+      cache.containsKey(param2),
+      true,
+      reason: 'param1 and param2 should be considered equal',
+    );
+
+    expect(
+      cache.containsKey(param3),
+      false,
+      reason: 'param1 and param3 should not be considered equal',
+    );
+
+    expect(
+      cache.containsKey(param4),
+      false,
+      reason:
+          'param1 and param4 should not be considered equal as order matters',
+    );
+  });
+}