ICS20 V2 Support for Multi Denom

[chatton]

Requirements document

Shout out to @charleenfei for all the work done so far in this PoC branch that we've been working on.

In the linked PoC, we have the spec changes implemented and unit and e2e tests passing (additional ones still need to be added)

In the PoC, we have some full unit tests and E2E tests passing and can be used as a reference, unit and e2e.

This issue will outline the proposed order of PR creation for the changes to be most easily reviewed.

IBC spec

1020

ADRs

Milestones

Implementation issues

• [ICS20-2] Add proto types for ICS20 V2 #5794
• [ICS20-2] Update MsgTransfer proto to accept []sdk.Coin #5799
• Implement required FungibleTokenPacketDataV2 interface methods #5795
• [ICS20-2] Add conversion function between v1 packet data and v2 packet data #6114
• Add getFungibleTokenPacketDataV2 and replace occurrences of FungibleTokenPacketData with it #5796
• Implement channel open application callbacks #5797
• [ICS20-2] Implement channel upgrade application callbacks. #5798
• Update sendTransfer to iterate over an array of coins #5801
• [ICS20-2] Validate application version and ensure backwards compatibility for sendTransfer #5803
• [ICS20-2] Implement OnRecvPacket #5804
• [ICS20-2] implement OnAcknowledgementPacket and refundPacket #5805
• Update Transfer Authz implementation to account for multi denom #5802
• [ICS20-2] Final cleanup for multi denom #6109

QA scenarios

Automated e2e tests

Pre-releases

Checklist

• Internal audit(s)
• External audit(s)
• Documentation
• Swagger
• Integration with ledger
• Integration with relayers:
  • Hermes
  • Rly

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged/assigned

[srdtrk]

When we are doing such a rewrite, is it also possible to migrate storage to "cosmossdk.io/collections"?

[damiannolan]

We should also test ledger support since MsgTransfer is being modified. I will add to the checklist on the issue