tests: add ibc test cases

[zsystm]

Description

This PR adds test coverage to verify that both IBC v1 and IBC v2 flows are working as expected in ExampleChain.

Coverage

File Name	Coverage
github.com/cosmos/evm/ibc/module.go	100.0%
github.com/cosmos/evm/ibc/utils.go	100.0%
github.com/cosmos/evm/tests/ibc/helper.go	81.0%
github.com/cosmos/evm/testutil/ibc.go	100.0%
github.com/cosmos/evm/x/erc20/ibc_middleware.go	91.7%
github.com/cosmos/evm/x/erc20/keeper/ibc_callbacks.go	87.9%
github.com/cosmos/evm/x/ibc/transfer/ibc_module.go	100.0%
github.com/cosmos/evm/x/ibc/transfer/keeper/keeper.go	100.0%
github.com/cosmos/evm/x/ibc/transfer/keeper/msg_server.go	100.0%
github.com/cosmos/evm/x/ibc/transfer/module.go	72.7%
github.com/cosmos/evm/x/ibc/transfer/v2/ibc_module.go	100.0%

# How to get coverage
go test -coverpkg=./... -coverprofile=coverage.out -tags=test ./... 
go tool cover -html=coverage.out -o coverage.html

Closes: #46

---

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• added a relevant changelog entry to the Unreleased section in CHANGELOG.md
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[dongsam]

Overall, this looks good to me

1. How about adding a test case to reach coverage this part as well?
2. We also need to add test cases for the ICS20-related precompile, but since the removal of authz dependency is currently in progress, it seems more efficient to handle it after that change is completed.

[zsystm]

Overall, this looks good to me

1. How about adding a test case to reach coverage this part as well?
2. We also need to add test cases for the ICS20-related precompile, but since the removal of authz dependency is currently in progress, it seems more efficient to handle it after that change is completed.

@dongsam

Thank you for your feedback. The part you mentioned is already covered by existing test cases.

Case1: Source native denom through IBC to ERC20 precompiled contract

	// Case 1. token pair is not registered and is a single hop IBC Coin
	// by checking the prefix we ensure that only coins not native from this chain are evaluated.
	// IsNativeFromSourceChain will check if the coin is native from the source chain.
	// If the coin denom starts with `factory/` then it is a token factory coin, and we should not convert it
	// NOTE: Check https://docs.osmosis.zone/osmosis-core/modules/tokenfactory/ for more information
	case !found && strings.HasPrefix(coin.Denom, "ibc/") && ibc.IsBaseDenomFromSourceChain(data.Denom):
		tokenPair, err := k.RegisterERC20Extension(ctx, coin.Denom)
		if err != nil {
			return channeltypes.NewErrorAcknowledgement(err)
		}

		ctx.EventManager().EmitEvents(
			sdk.Events{
				sdk.NewEvent(
					types.EventTypeRegisterERC20Extension,
					sdk.NewAttribute(types.AttributeCoinSourceChannel, packet.SourceChannel),
					sdk.NewAttribute(types.AttributeKeyERC20Token, tokenPair.Erc20Address),
					sdk.NewAttribute(types.AttributeKeyCosmosCoin, tokenPair.Denom),
				),
			},
		)
		return ack

This is tested in v2 and v1

Case2: Receiving ERC20 native coin through IBC

	// Case 2. native ERC20 token
	case found && pair.IsNativeERC20():
		// Token pair is disabled -> return
		if !pair.Enabled {
			return ack
		}

		balance := k.bankKeeper.GetBalance(ctx, recipient, coin.Denom)
		if err := k.ConvertCoinNativeERC20(ctx, pair, balance.Amount, common.BytesToAddress(recipient.Bytes()), recipient); err != nil {
			return channeltypes.NewErrorAcknowledgement(err)
		}

		// For now the only case we are interested in adding telemetry is a successful conversion.
		telemetry.IncrCounterWithLabels(
			[]string{types.ModuleName, "ibc", "on_recv", "total"},
			1,
			[]metrics.Label{
				telemetry.NewLabel("denom", coin.Denom),
				telemetry.NewLabel("source_channel", packet.SourceChannel),
				telemetry.NewLabel("source_port", packet.SourcePort),
			},
		)
	}

This is tested in v1
Note: Receiving ERC20 native coins via IBC is currently not supported in IBC v2, as it does not allow denoms containing /.

[zsystm]

Overall, this looks good to me

1. How about adding a test case to reach coverage this part as well?
2. We also need to add test cases for the ICS20-related precompile, but since the removal of authz dependency is currently in progress, it seems more efficient to handle it after that change is completed.

@dongsam

Regarding your second point about adding test cases for the ICS20-related precompile:

• Since the removal of the authz dependency is still in progress, I agree it would be more efficient to address the ICS20 test cases after that change is complete.
• To keep this PR focused, I suggest we validate the core middleware logic at the e2e level here and handle the ICS20-related tests in a separate PR. This way, we can ensure clear scope separation and tackle the ICS20 precompile tests as a dedicated topic once the dependency removal is finalized.

What do you think about this approach?

[dongsam]

@zsystm

already covered by existing test cases.

Ah, it seems like the coverage was mistakenly recognized as missing due to an issue with the measurement on my local environment. I confirmed that the breakpoint is hit and the coverage is reached in debug mode. 🙏

Regarding your second point about adding test cases for the ICS20-related precompile:

Yes, I agree that it would be better to handle the ICS20-related tests in a separate PR, as you suggested.

I’ll finish the review and proceed with the approval within today.

[dongsam]

It seems that the main ibc middleware cases are covered.

I’m currently working separately on test cases for the ICS20 precompile's transfer related to this issue.

Once it’s complete, I’ll open a PR and request a review.