feat: ✨ add ctx to RequestHandlerFunc for keeping the flow o… (#12)

examples/cqrs/internal/products/features/creating_product/commands/create_product_handler.go

@@ -2,6 +2,8 @@ package commands
 
 import (
 	"context"
+	"fmt"
+
 	"github.com/mehdihadeli/go-mediatr"
 	creatingProductDtos "github.com/mehdihadeli/go-mediatr/examples/cqrs/internal/products/features/creating_product/dtos"
 	"github.com/mehdihadeli/go-mediatr/examples/cqrs/internal/products/features/creating_product/events"
@@ -18,6 +20,10 @@ func NewCreateProductCommandHandler(productRepository *repository.InMemoryProduc
 }
 
 func (c *CreateProductCommandHandler) Handle(ctx context.Context, command *CreateProductCommand) (*creatingProductDtos.CreateProductCommandResponse, error) {
+	isLoggerPipelineEnabled := ctx.Value("logger_pipeline").(bool)
+	if isLoggerPipelineEnabled {
+		fmt.Println("[CreateProductCommandHandler]: logging pipeline is enabled")
+	}
 
 	product := &models.Product{
 		ProductID:   command.ProductID,

examples/cqrs/internal/shared/behaviours/request_logger_behaviour.go

@@ -2,8 +2,9 @@ package behaviours
 
 import (
 	"context"
-	"github.com/mehdihadeli/go-mediatr"
 	"log"
+
+	"github.com/mehdihadeli/go-mediatr"
 )
 
 type RequestLoggerBehaviour struct {
@@ -12,7 +13,10 @@ type RequestLoggerBehaviour struct {
 func (r *RequestLoggerBehaviour) Handle(ctx context.Context, request interface{}, next mediatr.RequestHandlerFunc) (interface{}, error) {
 	log.Printf("logging some stuff before handling the request")
 
-	response, err := next()
+	// https://golang.org/pkg/context/#Context
+	ctx = context.WithValue(ctx, "logger_pipeline", true)
+
+	response, err := next(ctx)
 	if err != nil {
 		return nil, err
 	}

mediatr.go

@@ -9,7 +9,7 @@ import (
 )
 
 // RequestHandlerFunc is a continuation for the next task to execute in the pipeline
-type RequestHandlerFunc func() (interface{}, error)
+type RequestHandlerFunc func(ctx context.Context) (interface{}, error)
 
 // PipelineBehavior is a Pipeline behavior for wrapping the inner handler.
 type PipelineBehavior interface {
@@ -116,7 +116,7 @@ func RegisterNotificationHandlers[TEvent any](handlers ...NotificationHandler[TE
 	return nil
 }
 
-// RegisterNotificationHandlers register the notification handlers factories to mediatr registry.
+// RegisterNotificationHandlersFactories register the notification handlers factories to mediatr registry.
 func RegisterNotificationHandlersFactories[TEvent any](factories ...NotificationHandlerFactory[TEvent]) error {
 	if len(factories) == 0 {
 		return errors.New("no handlers provided")
@@ -172,23 +172,23 @@ func Send[TRequest any, TResponse any](ctx context.Context, request TRequest) (T
 	if len(pipelineBehaviours) > 0 {
 		var reversPipes = reversOrder(pipelineBehaviours)
 
-		var lastHandler RequestHandlerFunc = func() (interface{}, error) {
+		var lastHandler RequestHandlerFunc = func(ctx context.Context) (interface{}, error) {
 			return handlerValue.Handle(ctx, request)
 		}
 
 		aggregateResult := linq.From(reversPipes).AggregateWithSeedT(lastHandler, func(next RequestHandlerFunc, pipe PipelineBehavior) RequestHandlerFunc {
 			pipeValue := pipe
 			nexValue := next
 
-			var handlerFunc RequestHandlerFunc = func() (interface{}, error) {
+			var handlerFunc RequestHandlerFunc = func(ctx context.Context) (interface{}, error) {
 				return pipeValue.Handle(ctx, request, nexValue)
 			}
 
 			return handlerFunc
 		})
 
 		v := aggregateResult.(RequestHandlerFunc)
-		response, err := v()
+		response, err := v(ctx)
 
 		if err != nil {
 			return *new(TResponse), errors.Wrap(err, "error handling request")

mediatr_test.go

@@ -455,7 +455,7 @@ func (c *PipelineBehaviourTest) Handle(ctx context.Context, request interface{},
 	fmt.Println("PipelineBehaviourTest.Handled")
 	testData = append(testData, "PipelineBehaviourTest")
 
-	res, err := next()
+	res, err := next(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -471,7 +471,7 @@ func (c *PipelineBehaviourTest2) Handle(ctx context.Context, request interface{}
 	fmt.Println("PipelineBehaviourTest2.Handled")
 	testData = append(testData, "PipelineBehaviourTest2")
 
-	res, err := next()
+	res, err := next(ctx)
 	if err != nil {
 		return nil, err
 	}