feat(x/auth/tx): extend app module + docs (backport #21409) (#21439)

Co-authored-by: Julien Robert <julien@rbrt.fr>

x/auth/module.go

@@ -51,7 +51,7 @@ type AppModule struct {
 // IsAppModule implements the appmodule.AppModule interface.
 func (am AppModule) IsAppModule() {}
 
-// NewAppModule creates a new AppModule object
+// NewAppModule creates a new AppModule object.
 func NewAppModule(
 	cdc codec.Codec,
 	accountKeeper keeper.AccountKeeper,

x/auth/tx/README.md

@@ -17,12 +17,15 @@ This document specifies the `x/auth/tx` package of the Cosmos SDK.
 
 This package represents the Cosmos SDK implementation of the `client.TxConfig`, `client.TxBuilder`, `client.TxEncoder` and `client.TxDecoder` interfaces.
 
+It contains as well a depinject module and app module the registration of ante/post handler via `runtime` and tx validator via `runtime/v2`.
+
 ## Contents
 
 * [Transactions](#transactions)
     * [`TxConfig`](#txconfig)
     * [`TxBuilder`](#txbuilder)
     * [`TxEncoder`/ `TxDecoder`](#txencoder-txdecoder)
+* [Depinject \& App Module](#depinject--app-module)
 * [Client](#client)
     * [CLI](#cli)
     * [gRPC](#grpc)
@@ -57,6 +60,13 @@ A `client.TxBuilder` can be accessed with `TxConfig.NewTxBuilder()`.
 
 More information about `TxEncoder` and `TxDecoder` can be found [here](https://docs.cosmos.network/main/core/encoding#transaction-encoding).
 
+## Depinject & App Module
+
+The `x/auth/tx/config` contains a depinject module and app module.
+The depinject module is there to setup ante/post handlers on an runtime app (via baseapp options) and the tx validator on the runtime/v2 app (via app module). It as well outputs the `TxConfig` and `TxConfigOptions` for the app.
+
+The app module is purely there for registering tx validators, due to the design of tx validators (tx validator belong to modules).
+
 ## Client
 
 ### CLI

x/auth/tx/config/depinject.go

@@ -14,8 +14,7 @@ import (
 	bankv1beta1 "cosmossdk.io/api/cosmos/bank/v1beta1"
 	txconfigv1 "cosmossdk.io/api/cosmos/tx/config/v1"
 	"cosmossdk.io/core/address"
-	"cosmossdk.io/core/appmodule"
-	appmodulev2 "cosmossdk.io/core/appmodule/v2"
+	"cosmossdk.io/core/appmodule/v2"
 	"cosmossdk.io/core/transaction"
 	"cosmossdk.io/depinject"
 	"cosmossdk.io/depinject/appconfig"
@@ -52,23 +51,24 @@ type ModuleInputs struct {
 	ProtoFileResolver     txsigning.ProtoFileResolver
 	Environment           appmodule.Environment
 	// BankKeeper is the expected bank keeper to be passed to AnteHandlers
-	BankKeeper               authtypes.BankKeeper               `optional:"true"`
-	MetadataBankKeeper       BankKeeper                         `optional:"true"`
-	AccountKeeper            ante.AccountKeeper                 `optional:"true"`
-	FeeGrantKeeper           ante.FeegrantKeeper                `optional:"true"`
-	AccountAbstractionKeeper ante.AccountAbstractionKeeper      `optional:"true"`
-	CustomSignModeHandlers   func() []txsigning.SignModeHandler `optional:"true"`
-	CustomGetSigners         []txsigning.CustomGetSigner        `optional:"true"`
-	UnorderedTxManager       *unorderedtx.Manager               `optional:"true"`
+	BankKeeper               authtypes.BankKeeper                    `optional:"true"`
+	MetadataBankKeeper       BankKeeper                              `optional:"true"`
+	AccountKeeper            ante.AccountKeeper                      `optional:"true"`
+	FeeGrantKeeper           ante.FeegrantKeeper                     `optional:"true"`
+	AccountAbstractionKeeper ante.AccountAbstractionKeeper           `optional:"true"`
+	CustomSignModeHandlers   func() []txsigning.SignModeHandler      `optional:"true"`
+	CustomGetSigners         []txsigning.CustomGetSigner             `optional:"true"`
+	UnorderedTxManager       *unorderedtx.Manager                    `optional:"true"`
+	ExtraTxValidators        []appmodule.TxValidator[transaction.Tx] `optional:"true"`
 }
 
 type ModuleOutputs struct {
 	depinject.Out
 
+	Module          appmodule.AppModule   // This is only useful for chains using server/v2. It setup tx validators that don't belong to other modules.
+	BaseAppOption   runtime.BaseAppOption // This is only useful for chains using baseapp. Server/v2 chains use TxValidator.
 	TxConfig        client.TxConfig
 	TxConfigOptions tx.ConfigOptions
-	BaseAppOption   runtime.BaseAppOption // This is only useful for chains using baseapp. Server/v2 chains use TxValidator.
-	Module          appmodule.AppModule
 }
 
 func ProvideProtoRegistry() txsigning.ProtoFileResolver {
@@ -152,9 +152,13 @@ func ProvideModule(in ModuleInputs) ModuleOutputs {
 		ante.DefaultSigVerificationGasConsumer,
 		in.AccountAbstractionKeeper,
 	)
-	appModule := AppModule{svd}
 
-	return ModuleOutputs{TxConfig: txConfig, TxConfigOptions: txConfigOptions, BaseAppOption: baseAppOption, Module: appModule}
+	return ModuleOutputs{
+		Module:          NewAppModule(svd, in.ExtraTxValidators...),
+		TxConfig:        txConfig,
+		TxConfigOptions: txConfigOptions,
+		BaseAppOption:   baseAppOption,
+	}
 }
 
 func newAnteHandler(txConfig client.TxConfig, in ModuleInputs) (sdk.AnteHandler, error) {
@@ -235,23 +239,3 @@ func metadataExists(err error) error {
 
 	return err
 }
-
-var (
-	_ appmodulev2.AppModule                      = AppModule{}
-	_ appmodulev2.HasTxValidator[transaction.Tx] = AppModule{}
-)
-
-type AppModule struct {
-	sigVerification ante.SigVerificationDecorator
-}
-
-// TxValidator implements appmodule.HasTxValidator.
-func (a AppModule) TxValidator(ctx context.Context, tx transaction.Tx) error {
-	return a.sigVerification.ValidateTx(ctx, tx)
-}
-
-// IsAppModule implements appmodule.AppModule.
-func (a AppModule) IsAppModule() {}
-
-// IsOnePerModuleType implements appmodule.AppModule.
-func (a AppModule) IsOnePerModuleType() {}

x/auth/tx/config/module.go

@@ -0,0 +1,54 @@
+package tx
+
+import (
+	"context"
+
+	appmodulev2 "cosmossdk.io/core/appmodule/v2"
+	"cosmossdk.io/core/transaction"
+	"cosmossdk.io/x/auth/ante"
+)
+
+var (
+	_ appmodulev2.AppModule                      = AppModule{}
+	_ appmodulev2.HasTxValidator[transaction.Tx] = AppModule{}
+)
+
+// AppModule is a module that only implements tx validators.
+// The goal of this module is to allow extensible registration of tx validators provided by chains without requiring a new modules.
+// Additionally, it registers tx validators that do not really have a place in other modules.
+// This module is only useful for chains using server/v2. Ante/Post handlers are setup via baseapp options in depinject.
+type AppModule struct {
+	sigVerification ante.SigVerificationDecorator
+	// txValidators contains tx validator that can be injected into the module via depinject.
+	// tx validators should be module based, but it can happen that you do not want to create a new module
+	// and simply depinject-it.
+	txValidators []appmodulev2.TxValidator[transaction.Tx]
+}
+
+// NewAppModule creates a new AppModule object.
+func NewAppModule(
+	sigVerification ante.SigVerificationDecorator,
+	txValidators ...appmodulev2.TxValidator[transaction.Tx],
+) AppModule {
+	return AppModule{
+		sigVerification: sigVerification,
+		txValidators:    txValidators,
+	}
+}
+
+// IsAppModule implements appmodule.AppModule.
+func (a AppModule) IsAppModule() {}
+
+// IsOnePerModuleType implements appmodule.AppModule.
+func (a AppModule) IsOnePerModuleType() {}
+
+// TxValidator implements appmodule.HasTxValidator.
+func (a AppModule) TxValidator(ctx context.Context, tx transaction.Tx) error {
+	for _, txValidator := range a.txValidators {
+		if err := txValidator.ValidateTx(ctx, tx); err != nil {
+			return err
+		}
+	}
+
+	return a.sigVerification.ValidateTx(ctx, tx)
+}