Add CW-1155 to implement EIP 1155

[sgoya]

This is a first pass at implementing cw-1155 for cw-nft repo.

[JakeHartnell]

Wow! This is looking really good! Made a few small comments, will take a deeper pass tomorrow.

[the-frey]

Code looks good, thanks for the contribution! However, a couple of fixups before merge please:

• CI is broken
• Tests need uncommenting and adding

[the-frey]

I haven't seen any other contract tests - so would expect these to be implemented and fixed before merge to be sure of the contract behaviour.

[sgoya]

Hi Ethan, sorry this is still super WIP. I wanted to get feedback on the state model before I add all the tests so that if we end up changing the state file, not too much code needs to be changed.

[the-frey]

ha, ethan is @ethanfrey - first time i've ever had a name collision with this handle

[sgoya]

I am so sorry, I saw frey and assumed incorrectly. Sorry about that.

[the-frey]

🙃 no worries haha

[giansalex]

cw1155 is not in cw-plus ?
https://github.com/CosmWasm/cw-plus/tree/main/contracts/cw1155-base

[JakeHartnell]

cw1155 is not in cw-plus ? https://github.com/CosmWasm/cw-plus/tree/main/contracts/cw1155-base

Probably makes sense for it to move here. Additionally, it would be nice to make it easily extensible similar to what's been done with cw721-base.

[ethanfrey]

I would love to see this here, so I can remove it from cw-plus. Both packages/cw1155 as well as contracts/cw1155-base.

I would propose a literal copy (and CI fix, etc) as a first PR. And when that is in a tagged release, some follow ups that modify it like cw721-base was extended.

I would note we just bumped cw-plus to v0.11.1. There are some nice helpers, especially about ranges and multi-indexes that should make life easier but will take some conversion. Maybe you can bump this repo to v0.11.1 first, and then push cw1155 as v0.11.2, so you can keep a progress on the same numbers as it was already published on crates.io

[JakeHartnell]

Closing in favor of #78