From d30f887090049e4ae6493632332afe6ae18f8526 Mon Sep 17 00:00:00 2001
From: Sean King <sean@seking.dev>
Date: Fri, 29 Apr 2022 18:41:56 +0200
Subject: [PATCH] adding default version for ics29

---
 modules/apps/29-fee/ibc_module.go      | 23 +++++++++++++++++------
 modules/apps/29-fee/ibc_module_test.go | 10 +++++++---
 testing/mock/ibc_module.go             |  5 +++++
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/modules/apps/29-fee/ibc_module.go b/modules/apps/29-fee/ibc_module.go
index 0767d310b41..00ea19b56f5 100644
--- a/modules/apps/29-fee/ibc_module.go
+++ b/modules/apps/29-fee/ibc_module.go
@@ -1,6 +1,8 @@
 package fee
 
 import (
+	"strings"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
@@ -38,12 +40,21 @@ func (im IBCModule) OnChanOpenInit(
 	version string,
 ) (string, error) {
 	var versionMetadata types.Metadata
-	if err := types.ModuleCdc.UnmarshalJSON([]byte(version), &versionMetadata); err != nil {
-		// Since it is valid for fee version to not be specified, the above middleware version may be for a middleware
-		// lower down in the stack. Thus, if it is not a fee version we pass the entire version string onto the underlying
-		// application.
-		return im.app.OnChanOpenInit(ctx, order, connectionHops, portID, channelID,
-			chanCap, counterparty, version)
+
+	if strings.TrimSpace(version) == "" {
+		// default version
+		versionMetadata = types.Metadata{
+			FeeVersion: types.Version,
+			AppVersion: "",
+		}
+	} else {
+		if err := types.ModuleCdc.UnmarshalJSON([]byte(version), &versionMetadata); err != nil {
+			// Since it is valid for fee version to not be specified, the above middleware version may be for a middleware
+			// lower down in the stack. Thus, if it is not a fee version we pass the entire version string onto the underlying
+			// application.
+			return im.app.OnChanOpenInit(ctx, order, connectionHops, portID, channelID,
+				chanCap, counterparty, version)
+		}
 	}
 
 	if versionMetadata.FeeVersion != types.Version {
diff --git a/modules/apps/29-fee/ibc_module_test.go b/modules/apps/29-fee/ibc_module_test.go
index 0bfb8a6b458..025c765e42c 100644
--- a/modules/apps/29-fee/ibc_module_test.go
+++ b/modules/apps/29-fee/ibc_module_test.go
@@ -54,6 +54,11 @@ func (suite *FeeTestSuite) TestOnChanOpenInit() {
 			types.Version,
 			false,
 		},
+		{
+			"passing an empty string returns default version",
+			"",
+			true,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -99,7 +104,6 @@ func (suite *FeeTestSuite) TestOnChanOpenInit() {
 				suite.path.EndpointA.ChannelConfig.PortID, suite.path.EndpointA.ChannelID, chanCap, counterparty, channel.Version)
 
 			if tc.expPass {
-
 				// check if the channel is fee enabled. If so version string should include metaData
 				isFeeEnabled := suite.chainA.GetSimApp().IBCFeeKeeper.IsFeeEnabled(suite.chainA.GetContext(), suite.path.EndpointA.ChannelConfig.PortID, suite.path.EndpointA.ChannelID)
 				if isFeeEnabled {
@@ -113,13 +117,13 @@ func (suite *FeeTestSuite) TestOnChanOpenInit() {
 
 					suite.Require().Equal(version, string(versionBytes))
 				} else {
-					suite.Require().Equal(version, ibcmock.Version)
+					suite.Require().Equal(ibcmock.Version, version)
 				}
 
 				suite.Require().NoError(err, "unexpected error from version: %s", tc.version)
 			} else {
 				suite.Require().Error(err, "error not returned for version: %s", tc.version)
-				suite.Require().Equal(version, "")
+				suite.Require().Equal("", version)
 			}
 		})
 	}
diff --git a/testing/mock/ibc_module.go b/testing/mock/ibc_module.go
index 4c492872da0..69f3c388a8a 100644
--- a/testing/mock/ibc_module.go
+++ b/testing/mock/ibc_module.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"strconv"
+	"strings"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
@@ -33,6 +34,10 @@ func (im IBCModule) OnChanOpenInit(
 	ctx sdk.Context, order channeltypes.Order, connectionHops []string, portID string,
 	channelID string, chanCap *capabilitytypes.Capability, counterparty channeltypes.Counterparty, version string,
 ) (string, error) {
+	if strings.TrimSpace(version) == "" {
+		version = Version
+	}
+
 	if im.IBCApp.OnChanOpenInit != nil {
 		return im.IBCApp.OnChanOpenInit(ctx, order, connectionHops, portID, channelID, chanCap, counterparty, version)
 	}