refactor(core): re-add handlers (#21575)

core/appmodule/v2/handlers.go

@@ -2,6 +2,7 @@ package appmodulev2
 
 import (
 	"context"
+	"fmt"
 
 	transaction "cosmossdk.io/core/transaction"
 )
@@ -16,47 +17,152 @@ type (
 	PostMsgHandler = func(ctx context.Context, msg, msgResp transaction.Msg) error
 )
 
-// msg handler
-
+// PreMsgRouter is a router that allows you to register PreMsgHandlers for specific message types.
 type PreMsgRouter interface {
 	// RegisterPreHandler will register a specific message handler hooking into the message with
 	// the provided name.
-	RegisterPreHandler(msgName string, handler PreMsgHandler)
+	RegisterPreMsgHandler(msgName string, handler PreMsgHandler)
 	// RegisterGlobalPreHandler will register a global message handler hooking into any message
 	// being executed.
-	RegisterGlobalPreHandler(handler PreMsgHandler)
+	RegisterGlobalPreMsgHandler(handler PreMsgHandler)
 }
 
+// HasPreMsgHandlers is an interface that modules must implement if they want to register PreMsgHandlers.
 type HasPreMsgHandlers interface {
 	RegisterPreMsgHandlers(router PreMsgRouter)
 }
 
-type MsgRouter interface {
-	Register(msgName string, handler Handler)
-}
+// RegisterMsgPreHandler is a helper function that modules can use to not lose type safety when registering PreMsgHandler to the
+// PreMsgRouter. Example usage:
+// ```go
+//
+//	func (h Handlers) BeforeSend(ctx context.Context, req *types.MsgSend) error {
+//	      ... before send logic ...
+//	}
+//
+//	func (m Module) RegisterPreMsgHandlers(router appmodule.PreMsgRouter) {
+//		handlers := keeper.NewHandlers(m.keeper)
+//	    appmodule.RegisterMsgPreHandler(router, gogoproto.MessageName(types.MsgSend{}), handlers.BeforeSend)
+//	}
+//
+// ```
+func RegisterMsgPreHandler[Req transaction.Msg](
+	router PreMsgRouter,
+	msgName string,
+	handler func(ctx context.Context, msg Req) error,
+) {
+	untypedHandler := func(ctx context.Context, m transaction.Msg) error {
+		typed, ok := m.(Req)
+		if !ok {
+			return fmt.Errorf("unexpected type %T, wanted: %T", m, *new(Req))
+		}
+		return handler(ctx, typed)
+	}
 
-type HasMsgHandlers interface {
-	RegisterMsgHandlers(router MsgRouter)
+	router.RegisterPreMsgHandler(msgName, untypedHandler)
 }
 
+// PostMsgRouter is a router that allows you to register PostMsgHandlers for specific message types.
 type PostMsgRouter interface {
 	// RegisterPostHandler will register a specific message handler hooking after the execution of message with
 	// the provided name.
-	RegisterPostHandler(msgName string, handler PostMsgHandler)
+	RegisterPostMsgHandler(msgName string, handler PostMsgHandler)
 	// RegisterGlobalPostHandler will register a global message handler hooking after the execution of any message.
-	RegisterGlobalPostHandler(handler PostMsgHandler)
+	RegisterGlobalPostMsgHandler(handler PostMsgHandler)
 }
 
+// HasPostMsgHandlers is an interface that modules must implement if they want to register PostMsgHandlers.
 type HasPostMsgHandlers interface {
 	RegisterPostMsgHandlers(router PostMsgRouter)
 }
 
-// query handler
+// RegisterPostHandler is a helper function that modules can use to not lose type safety when registering handlers to the
+// PostMsgRouter. Example usage:
+// ```go
+//
+//	func (h Handlers) AfterSend(ctx context.Context, req *types.MsgSend, resp *types.MsgSendResponse) error {
+//	      ... query logic ...
+//	}
+//
+//	func (m Module) RegisterPostMsgHandlers(router appmodule.PostMsgRouter) {
+//		handlers := keeper.NewHandlers(m.keeper)
+//	    appmodule.RegisterPostMsgHandler(router, gogoproto.MessageName(types.MsgSend{}), handlers.AfterSend)
+//	}
+//
+// ```
+func RegisterPostMsgHandler[Req, Resp transaction.Msg](
+	router PostMsgRouter,
+	msgName string,
+	handler func(ctx context.Context, msg Req, msgResp Resp) error,
+) {
+	untypedHandler := func(ctx context.Context, m, mResp transaction.Msg) error {
+		typed, ok := m.(Req)
+		if !ok {
+			return fmt.Errorf("unexpected type %T, wanted: %T", m, *new(Req))
+		}
+		typedResp, ok := mResp.(Resp)
+		if !ok {
+			return fmt.Errorf("unexpected type %T, wanted: %T", m, *new(Resp))
+		}
+		return handler(ctx, typed, typedResp)
+	}
+
+	router.RegisterPostMsgHandler(msgName, untypedHandler)
+}
+
+// MsgRouter is a router that allows you to register Handlers for specific message types.
+type MsgRouter = interface {
+	RegisterHandler(msgName string, handler Handler) error
+}
 
-type QueryRouter interface {
-	Register(queryName string, handler Handler)
+// HasMsgHandlers is an interface that modules must implement if they want to register Handlers.
+type HasMsgHandlers interface {
+	RegisterMsgHandlers(router MsgRouter)
 }
 
+// QueryRouter is a router that allows you to register QueryHandlers for specific query types.
+type QueryRouter = MsgRouter
+
+// HasQueryHandlers is an interface that modules must implement if they want to register QueryHandlers.
 type HasQueryHandlers interface {
 	RegisterQueryHandlers(router QueryRouter)
 }
+
+// RegisterMsgHandler is a helper function that modules can use to not lose type safety when registering handlers to the MsgRouter and Query Router.
+// Example usage:
+// ```go
+//
+//	func (h Handlers) Mint(ctx context.Context, req *types.MsgMint) (*types.MsgMintResponse, error) {
+//	      ... msg logic ...
+//	}
+//
+//	func (h Handlers) QueryBalance(ctx context.Context, req *types.QueryBalanceRequest) (*types.QueryBalanceResponse, error) {
+//	      ... query logic ...
+//	}
+//
+//	func (m Module) RegisterMsgHandlers(router appmodule.MsgRouter) {
+//		handlers := keeper.NewHandlers(m.keeper)
+//	    err := appmodule.RegisterHandler(router, gogoproto.MessageName(types.MsgMint{}), handlers.MsgMint)
+//	}
+//
+//	func (m Module) RegisterQueryHandlers(router appmodule.QueryRouter) {
+//		handlers := keeper.NewHandlers(m.keeper)
+//	    err := appmodule.RegisterHandler(router, gogoproto.MessageName(types.QueryBalanceRequest{}), handlers.QueryBalance)
+//	}
+//
+// ```
+func RegisterHandler[Req, Resp transaction.Msg](
+	router MsgRouter,
+	msgName string,
+	handler func(ctx context.Context, msg Req) (msgResp Resp, err error),
+) error {
+	untypedHandler := func(ctx context.Context, m transaction.Msg) (transaction.Msg, error) {
+		typed, ok := m.(Req)
+		if !ok {
+			return nil, fmt.Errorf("unexpected type %T, wanted: %T", m, *new(Req))
+		}
+		return handler(ctx, typed)
+	}
+
+	return router.RegisterHandler(msgName, untypedHandler)
+}

runtime/v2/manager.go

@@ -604,14 +604,19 @@ func registerServices[T transaction.Tx](s hasServicesV1, app *App[T], registry *
 		err:               nil,
 	}
 
-	err := s.RegisterServices(c)
-	if err != nil {
+	if err := s.RegisterServices(c); err != nil {
 		return fmt.Errorf("unable to register services: %w", err)
 	}
+
+	if c.err != nil {
+		app.logger.Warn("error registering services", "error", c.err)
+	}
+
 	// merge maps
 	for path, decoder := range c.grpcQueryDecoders {
 		app.GRPCMethodsToMessageMap[path] = decoder
 	}
+
 	return nil
 }
 
@@ -654,7 +659,7 @@ func (c *configurator) registerQueryHandlers(sd *grpc.ServiceDesc, ss interface{
 		// TODO(tip): what if a query is not deterministic?
 		requestFullName, err := registerMethod(c.stfQueryRouter, sd, md, ss)
 		if err != nil {
-			return fmt.Errorf("unable to register query handler %s: %w", md.MethodName, err)
+			return fmt.Errorf("unable to register query handler %s.%s: %w", sd.ServiceName, md.MethodName, err)
 		}
 
 		// register gRPC query method.
@@ -675,7 +680,7 @@ func (c *configurator) registerMsgHandlers(sd *grpc.ServiceDesc, ss interface{})
 	for _, md := range sd.Methods {
 		_, err := registerMethod(c.stfMsgRouter, sd, md, ss)
 		if err != nil {
-			return fmt.Errorf("unable to register msg handler %s: %w", md.MethodName, err)
+			return fmt.Errorf("unable to register msg handler %s.%s: %w", sd.ServiceName, md.MethodName, err)
 		}
 	}
 	return nil

server/v2/stf/stf_router.go

@@ -41,19 +41,19 @@ func (b *MsgRouterBuilder) RegisterHandler(msgType string, handler appmodulev2.H
 	return nil
 }
 
-func (b *MsgRouterBuilder) RegisterGlobalPreHandler(handler appmodulev2.PreMsgHandler) {
+func (b *MsgRouterBuilder) RegisterGlobalPreMsgHandler(handler appmodulev2.PreMsgHandler) {
 	b.globalPreHandlers = append(b.globalPreHandlers, handler)
 }
 
-func (b *MsgRouterBuilder) RegisterPreHandler(msgType string, handler appmodulev2.PreMsgHandler) {
+func (b *MsgRouterBuilder) RegisterPreMsgHandler(msgType string, handler appmodulev2.PreMsgHandler) {
 	b.preHandlers[msgType] = append(b.preHandlers[msgType], handler)
 }
 
-func (b *MsgRouterBuilder) RegisterPostHandler(msgType string, handler appmodulev2.PostMsgHandler) {
+func (b *MsgRouterBuilder) RegisterPostMsgHandler(msgType string, handler appmodulev2.PostMsgHandler) {
 	b.postHandlers[msgType] = append(b.postHandlers[msgType], handler)
 }
 
-func (b *MsgRouterBuilder) RegisterGlobalPostHandler(handler appmodulev2.PostMsgHandler) {
+func (b *MsgRouterBuilder) RegisterGlobalPostMsgHandler(handler appmodulev2.PostMsgHandler) {
 	b.globalPostHandlers = append(b.globalPostHandlers, handler)
 }