Align pipeline behavior (#10)

* Change to set

* Rename handlers -> behaviors

* Correct generic type names

* Add assertion test

* Update getPipelines to return a set of behaviors

lib/src/request/pipeline/pipeline_behavior.dart

@@ -6,8 +6,8 @@ import 'package:meta/meta.dart';
 typedef RequestHandlerDelegate<TResponse> = FutureOr<TResponse> Function();
 
 /// Factory to create a [PipelineBehavior].
-typedef PipelineBehaviorFactory<TRequest, TResponse>
-    = PipelineBehavior<TRequest, TResponse> Function();
+typedef PipelineBehaviorFactory<TResponse, TRequest>
+    = PipelineBehavior<TResponse, TRequest> Function();
 
 typedef PipelineHandler<TResponse, TRequest> = FutureOr<TResponse> Function(
     TRequest, RequestHandlerDelegate<TResponse>);

lib/src/request/pipeline/pipeline_behavior_store.dart

@@ -3,16 +3,21 @@ import 'package:dart_mediator/src/request/pipeline/pipeline_configurator.dart';
 import 'package:dart_mediator/src/request/pipeline/pipeline_behavior.dart';
 
 class PipelineBehaviorStore implements PipelineConfigurator {
-  final _handlers = <Type, List<PipelineBehavior>>{};
-  final _genericHandlers = <PipelineBehavior>{};
+  final _typedBehaviors = <Type, Set<PipelineBehavior>>{};
+  final _genericBehaviors = <PipelineBehavior>{};
 
   @override
   void register<TResponse extends Object?, TRequest extends Request<TResponse>>(
     PipelineBehavior<TResponse, TRequest> behavior,
   ) {
-    final handlers = _handlers.putIfAbsent(
+    final handlers = _typedBehaviors.putIfAbsent(
       TRequest,
-      () => <PipelineBehavior>[],
+      () => <PipelineBehavior>{},
+    );
+
+    assert(
+      !handlers.contains(behavior),
+      'register<$TResponse, $TRequest> was called with an already registered behavior',
     );
 
     handlers.add(behavior);
@@ -22,45 +27,50 @@ class PipelineBehaviorStore implements PipelineConfigurator {
   void registerGeneric(
     PipelineBehavior behavior,
   ) {
-    _genericHandlers.add(behavior);
+    assert(
+      !_genericBehaviors.contains(behavior),
+      'registerGeneric was called with an already registered behavior',
+    );
+
+    _genericBehaviors.add(behavior);
   }
 
   @override
   void unregister<TResponse extends Object?,
       TRequest extends Request<TResponse>>(
     PipelineBehavior<TResponse, TRequest> behavior,
   ) {
-    final handlers = _handlers[TRequest];
+    final behaviors = _typedBehaviors[TRequest];
 
     assert(
-      handlers != null,
+      behaviors != null && behaviors.contains(behavior),
       'unregister<$TResponse, $TRequest> was called for a behavior that was never registered',
     );
 
-    handlers!.remove(behavior);
+    behaviors!.remove(behavior);
   }
 
   @override
   void unregisterGeneric(PipelineBehavior behavior) {
     assert(
-      _genericHandlers.contains(behavior),
+      _genericBehaviors.contains(behavior),
       'unregisterGeneric was called for a behavior that was never registered',
     );
 
-    _genericHandlers.remove(behavior);
+    _genericBehaviors.remove(behavior);
   }
 
   /// Returns all [PipelineBehavior]'s that match.
-  List<PipelineBehavior> getPipelines(
+  Set<PipelineBehavior> getPipelines(
     Request request,
   ) {
     final requestType = request.runtimeType;
 
-    final handlers = _handlers[requestType];
+    final behaviors = _typedBehaviors[requestType];
 
-    return [
-      if (handlers != null) ...handlers,
-      ..._genericHandlers,
-    ];
+    return {
+      if (behaviors != null) ...behaviors,
+      ..._genericBehaviors,
+    };
   }
 }

test/unit/request/pipeline_behavior/pipeline_behavior_store_test.dart

@@ -16,7 +16,7 @@ void main() {
     group('register', () {
       final mockBehavior = MockPipelineBehavior<int, MockRequest<int>>();
 
-      test('it registers the handler', () {
+      test('it registers the behavior', () {
         expect(
           () => pipelineBehaviorStore.register(mockBehavior),
           returnsNormally,
@@ -27,6 +27,18 @@ void main() {
           [mockBehavior],
         );
       });
+
+      test('it throws when the behavior was already registered', () {
+        expect(
+          () => pipelineBehaviorStore.register(mockBehavior),
+          returnsNormally,
+        );
+
+        expect(
+          () => pipelineBehaviorStore.register(mockBehavior),
+          throwsAssertionError,
+        );
+      });
     });
 
     group('registerGenericFunction', () {
@@ -81,7 +93,7 @@ void main() {
     group('registerGeneric', () {
       final mockBehavior = MockPipelineBehavior();
 
-      test('it registers the handler', () {
+      test('it registers the behavior', () {
         expect(
           () => pipelineBehaviorStore.registerGeneric(mockBehavior),
           returnsNormally,
@@ -97,7 +109,7 @@ void main() {
     group('registerGenericFactory', () {
       MockPipelineBehavior factory() => MockPipelineBehavior();
 
-      test('it registers the handler', () {
+      test('it registers the behavior', () {
         expect(
           () => pipelineBehaviorStore.registerGenericFactory(factory),
           returnsNormally,
@@ -127,7 +139,21 @@ void main() {
         );
       });
 
-      test('it throws when behavior does not exist', () {
+      test('it throws when behavior type does not exist', () {
+        expect(
+          () => pipelineBehaviorStore.unregister(mockBehavior),
+          throwsAssertionError,
+        );
+      });
+
+      test('it throws when the behavior does not exist', () {
+        pipelineBehaviorStore.register(mockBehavior);
+
+        expect(
+          () => pipelineBehaviorStore.unregister(mockBehavior),
+          returnsNormally,
+        );
+
         expect(
           () => pipelineBehaviorStore.unregister(mockBehavior),
           throwsAssertionError,
@@ -222,17 +248,18 @@ void main() {
         // Will not be returned in the getPipelines call.
         pipelineBehaviorStore.register(incorrectBehavior);
         pipelineBehaviorStore.registerFactory(incorrectFactory);
+        pipelineBehaviorStore.registerFunction(incorrectBehavior.handle);
 
         expect(
           pipelineBehaviorStore.getPipelines(mockRequest),
-          [
+          {
             correctBehavior,
             PipelineBehavior.function(correctBehavior.handle),
             PipelineBehavior.factory(correctFactory),
             logBehavior,
             PipelineBehavior.function(logBehavior.handle),
             PipelineBehavior.factory(logBehaviorFactory),
-          ],
+          },
         );
       });
     });

test/unit/request/requests_manager_test.dart

@@ -99,7 +99,7 @@ void main() {
             .thenReturn(mockRequestHandler);
 
         when(() => mockPipelineBehaviorStore.getPipelines(mockRequest))
-            .thenReturn([]);
+            .thenReturn({});
 
         final result = await requestsManager.send(mockRequest);
 
@@ -134,7 +134,7 @@ void main() {
         });
 
         when(() => mockPipelineBehaviorStore.getPipelines(mockRequest))
-            .thenReturn([mockBehavior]);
+            .thenReturn({mockBehavior});
 
         final result = await requestsManager.send(mockRequest);
 
@@ -166,7 +166,7 @@ void main() {
         });
 
         when(() => mockPipelineBehaviorStore.getPipelines(mockRequest))
-            .thenReturn([mockWrongBehavior]);
+            .thenReturn({mockWrongBehavior});
 
         await expectLater(
           () => requestsManager.send(mockRequest),