added support for PERMIT2_TRANSFER_FROM_BATCH, closes #106

[SOGeKING-NUL]

Summary

closes #106

• Implemented PERMIT2_TRANSFER_FROM_BATCH command encoding (command id 13)
• Added chained encoder API to batch transfer multiple tokens via Permit2
• Updated ABI builder and command map to support a tuple[] of AllowanceTransferDetails
• Added unit test verifying exact calldata for a two-transfer batch

Implementation Details

• Enums: Added RouterFunction.PERMIT2_TRANSFER_FROM_BATCH = 13

• ABI:

  • New_build_permit2_transfer_from_batch()producing a single parameter: AllowanceTransferDetails[]
  • Struct layout: (from, to, amount, token) as (address, address, uint256, address)
  • Registered in build_abi_map

• Encoder:

  • New permit2_transfer_from_batch(transfer_details: List[Dict])
  • Validates inputs and converts dicts to ordered tuples (from, to, amount, token) before ABI encode
  • Integrates into existing chained builder flow

• Tests:

  • Core test asserts exact calldata for two transfers (USDC + WETH)
  • Validation test kept out per request to keep tests minimal

  Screenshot

[SOGeKING-NUL]

@Elnaril any input or improvement for this pr?

[Elnaril]

Hi @SOGeKING-NUL
Thanks for your PR, but it needs to pass the CI checks to be considered for review.
Or do you mean you need help with that ?

[SOGeKING-NUL]

would like some help with that, what changes would I need to make for the CI checks to pass? do I need to tinker with some other files for this?

[Elnaril]

You have a mypy error in _encoder.py:

[SOGeKING-NUL]

@Elnaril fixed the issue, please review pr now :)

[Elnaril]

Hey @SOGeKING-NUL , thanks for this nice PR! :) The core is spot-on and well commented. 👍

Having said that, there are some missing parts:

• I'd like to add the decoding of an actual mainnet transaction in test_decoder.py::test_decode_transaction (let me know if you can't find one)
• Also an integration test should be added or modified to demonstrate the implementation of this new function works as expected.

Also, please have a look to my other comments.

[Elnaril]

And the coverage must stay at 100%

[SOGeKING-NUL]

noted, will work on changes

[SOGeKING-NUL]

@Elnaril does this solve a lot of the issues? also could you tell me more about adding the decoding of an actual mainnet transaction

[Elnaril]

@SOGeKING-NUL Yes, it solved all the code issues and the coverage. 👍

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also could you tell me more about adding the decoding of an actual mainnet transaction

The idea is to find a transaction which:

• happened on Ethereum Mainnet
• called PERMIT2_TRANSFER_FROM_BATCH
• ideally performing more than one transfer using this function
• decode it in test_decoder.py::test_decode_transaction

To find such transaction, you could either use Etherscan or figure out a programmatic approach.
Does it make sense ?

---

Apart from that, the remaining tasks are:

• integration test
• squash commits (so 1 PR =1 commit before I merge it)

[Elnaril]

@SOGeKING-NUL
It does not seem easy to find an actual transaction using this newly supported UR command ...
So probably best not to waste too much time on this part. The integration test will be enough to prove the implementation is correct.

[Elnaril]

Finally found one ! 😅
0x2ab1c28cf84f5e4b4db07e1be2e6f45f9c07e5d3b2ad80396e51c12d8db2b180
Please add it to test_decoder.py::test_decode_transaction