refactor(bloc): use Object.hashAll (#4310)

Author: felangel

packages/bloc/lib/src/change.dart

@@ -24,7 +24,7 @@ class Change<State> {
           nextState == other.nextState;
 
   @override
-  int get hashCode => currentState.hashCode ^ nextState.hashCode;
+  int get hashCode => Object.hashAll([currentState, nextState]);
 
   @override
   String toString() {

packages/bloc/lib/src/transition.dart

@@ -27,9 +27,7 @@ class Transition<Event, State> extends Change<State> {
           nextState == other.nextState;
 
   @override
-  int get hashCode {
-    return currentState.hashCode ^ event.hashCode ^ nextState.hashCode;
-  }
+  int get hashCode => Object.hashAll([currentState, event, nextState]);
 
   @override
   String toString() {

packages/bloc/pubspec.yaml

@@ -9,7 +9,7 @@ topics: [bloc, state-management]
 funding: [https://github.com/sponsors/felangel]
 
 environment:
-  sdk: ">=2.12.0 <4.0.0"
+  sdk: ">=2.14.0 <4.0.0"
 
 dependencies:
   meta: ^1.3.0

packages/bloc/test/blocs/async/async_event.dart

@@ -13,7 +13,7 @@ class AsyncEvent {
       other is AsyncEvent && runtimeType == other.runtimeType;
 
   @override
-  int get hashCode => runtimeType.hashCode;
+  int get hashCode => Object.hashAll([runtimeType]);
 
   @override
   String toString() => 'AsyncEvent';

packages/bloc/test/blocs/async/async_state.dart

@@ -43,8 +43,7 @@ class AsyncState {
           isSuccess == other.isSuccess;
 
   @override
-  int get hashCode =>
-      isLoading.hashCode ^ hasError.hashCode ^ isSuccess.hashCode;
+  int get hashCode => Object.hashAll([isLoading, hasError, isSuccess]);
 
   @override
   String toString() =>

packages/bloc/test/transition_test.dart

@@ -25,7 +25,7 @@ class CounterEvent extends TransitionEvent {
           eventData == other.eventData;
 
   @override
-  int get hashCode => eventData.hashCode;
+  int get hashCode => Object.hashAll([eventData]);
 }
 
 class CounterState extends TransitionState {
@@ -41,7 +41,7 @@ class CounterState extends TransitionState {
           count == other.count;
 
   @override
-  int get hashCode => count.hashCode;
+  int get hashCode => Object.hashAll([count]);
 }
 
 void main() {
@@ -78,7 +78,7 @@ void main() {
         const change = Change<int>(currentState: 0, nextState: 1);
         expect(
           change.hashCode,
-          change.currentState.hashCode ^ change.nextState.hashCode,
+          Object.hashAll([change.currentState, change.nextState]),
         );
       });
     });
@@ -196,9 +196,11 @@ void main() {
         );
         expect(
           transition.hashCode,
-          transition.currentState.hashCode ^
-              transition.event.hashCode ^
-              transition.nextState.hashCode,
+          Object.hashAll([
+            transition.currentState,
+            transition.event,
+            transition.nextState,
+          ]),
         );
       });
     });