do handshake logic, create test file

modules/apps/29-fee/module.go

@@ -1,6 +1,5 @@
 package fee
 
-/*
 import (
 	"context"
 	"encoding/json"
@@ -90,12 +89,14 @@ func (AppModuleBasic) GetQueryCmd() *cobra.Command {
 type AppModule struct {
 	AppModuleBasic
 	keeper keeper.Keeper
+	app    porttypes.IBCModule
 }
 
 // NewAppModule creates a new 29-fee module
-func NewAppModule(k keeper.Keeper) AppModule {
+func NewAppModule(k keeper.Keeper, app porttypes.IBCModule) AppModule {
 	return AppModule{
 		keeper: k,
+		app:    app,
 	}
 }
 
@@ -191,7 +192,13 @@ func (am AppModule) OnChanOpenInit(
 	counterparty channeltypes.Counterparty,
 	version string,
 ) error {
-	return nil
+	feeVersion, appVersion := channeltypes.SplitChannelVersion(version)
+	if feeVersion != types.Version {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "expected: %s, got: %s", types.Version, feeVersion)
+	}
+	// call underlying app's OnChanOpenInit callback with the appVersion
+	return am.app.OnChanOpenInit(ctx, order, connectionHops, portID, channelID,
+		chanCap, counterparty, appVersion)
 }
 
 // OnChanOpenTry implements the IBCModule interface
@@ -206,7 +213,18 @@ func (am AppModule) OnChanOpenTry(
 	version,
 	counterpartyVersion string,
 ) error {
-	return nil
+	feeVersion, appVersion := channeltypes.SplitChannelVersion(version)
+	cpFeeVersion, cpAppVersion := channeltypes.SplitChannelVersion(counterpartyVersion)
+
+	if feeVersion != types.Version {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "expected: %s, got: %s", types.Version, feeVersion)
+	}
+	if cpFeeVersion != feeVersion {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "expected counterparty version: %s, got: %s", types.Version, cpFeeVersion)
+	}
+	// call underlying app's OnChanOpenTry callback with the app versions
+	return am.app.OnChanOpenTry(ctx, order, connectionHops, portID, channelID,
+		chanCap, counterparty, appVersion, cpAppVersion)
 }
 
 // OnChanOpenAck implements the IBCModule interface
@@ -216,7 +234,13 @@ func (am AppModule) OnChanOpenAck(
 	channelID string,
 	counterpartyVersion string,
 ) error {
-	return nil
+	cpFeeVersion, cpAppVersion := channeltypes.SplitChannelVersion(counterpartyVersion)
+
+	if cpFeeVersion != types.Version {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "expected counterparty version: %s, got: %s", types.Version, cpFeeVersion)
+	}
+	// call underlying app's OnChanOpenAck callback with the counterparty app version.
+	return am.app.OnChanOpenAck(ctx, portID, channelID, cpAppVersion)
 }
 
 // OnChanOpenConfirm implements the IBCModule interface
@@ -225,7 +249,8 @@ func (am AppModule) OnChanOpenConfirm(
 	portID,
 	channelID string,
 ) error {
-	return nil
+	// call underlying app's OnChanOpenConfirm callback.
+	return am.app.OnChanOpenConfirm(ctx, portID, channelID)
 }
 
 // OnChanCloseInit implements the IBCModule interface
@@ -234,8 +259,8 @@ func (am AppModule) OnChanCloseInit(
 	portID,
 	channelID string,
 ) error {
-	// Disallow user-initiated channel closing for 29-fee channels
-	return sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "user cannot close channel")
+	// TODO: Unescrow all remaining funds for unprocessed packets
+	return am.app.OnChanCloseInit(ctx, portID, channelID)
 }
 
 // OnChanCloseConfirm implements the IBCModule interface
@@ -244,7 +269,8 @@ func (am AppModule) OnChanCloseConfirm(
 	portID,
 	channelID string,
 ) error {
-	return nil
+	// TODO: Unescrow all remaining funds for unprocessed packets
+	return am.app.OnChanCloseConfirm(ctx, portID, channelID)
 }
 
 // OnRecvPacket implements the IBCModule interface.
@@ -274,4 +300,3 @@ func (am AppModule) OnTimeoutPacket(
 ) error {
 	return nil
 }
-*/

modules/apps/29-fee/types/errors.go

@@ -1,8 +1,10 @@
 package types
 
 import (
-//	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
 
 // 29-fee sentinel errors
-var ()
+var (
+	ErrInvalidVersion = sdkerrors.Register(ModuleName, 2, "invalid ICS29 middleware version")
+)

modules/apps/29-fee/types/keys.go

@@ -12,4 +12,6 @@ const (
 
 	// QuerierRoute is the querier route for IBC transfer
 	QuerierRoute = ModuleName
+
+	Version = "fee29-1"
 )

modules/core/04-channel/types/version.go

@@ -0,0 +1,19 @@
+package types
+
+import "strings"
+
+// SplitChannelVersion middleware version will split the channel version string
+// into the outermost middleware version and the underlying app version.
+// It will use the default delimiter `:` for middleware versions.
+// In case there's no delimeter, this function returns an empty string for the middleware version (first return argument),
+// and the full input as the second underlying app version.
+func SplitChannelVersion(version string) (middlewareVersion, appVersion string) {
+	// only split out the first middleware version
+	splitVersions := strings.Split(version, ":")
+	if len(splitVersions) == 1 {
+		return "", version
+	}
+	middlewareVersion = splitVersions[0]
+	appVersion = strings.Join(splitVersions[1:], ":")
+	return
+}

modules/core/04-channel/types/version_test.go

@@ -0,0 +1,43 @@
+package types_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/cosmos/ibc-go/modules/core/04-channel/types"
+)
+
+func TestSplitVersions(t *testing.T) {
+	testCases := []struct {
+		name       string
+		version    string
+		mwVersion  string
+		appVersion string
+	}{
+		{
+			"single wrapped middleware",
+			"fee29-1:ics20-1",
+			"fee29-1",
+			"ics20-1",
+		},
+		{
+			"multiple wrapped middleware",
+			"fee29-1:whitelist:ics20-1",
+			"fee29-1",
+			"whitelist:ics20-1",
+		},
+		{
+			"no middleware",
+			"ics20-1",
+			"",
+			"ics20-1",
+		},
+	}
+
+	for _, tc := range testCases {
+		mwVersion, appVersion := types.SplitChannelVersion(tc.version)
+		require.Equal(t, tc.mwVersion, mwVersion, "middleware version is unexpected for case: %s", tc.name)
+		require.Equal(t, tc.appVersion, appVersion, "app version is unexpected for case: %s", tc.name)
+	}
+}