feat(target_chains/ethereum): add arbirum stylus sdk

[Ifechukwudaniel]

I’m currently working on the early draft of the Stylus SDK, focusing on documentation, writing examples, and conducting end-to-end testing for the SDK

[vercel]

@Ifechukwudaniel is attempting to deploy a commit to the Pyth Network Team on Vercel.

A member of the Team first needs to authorize it.

[Ifechukwudaniel]

This is an early draft of the Pyth stylus SDK. Using external calls. I am working on the examples

[Ifechukwudaniel]

This looks very promising overall. However, I think you should try to use sol_interface! macro to facilitate cross-contract calls, as recommended by the Stylus docs. Please see the comments for details.

The issue with this approach is the return type. The sol_interface! {} does not support custom types like PriceFeed or Price. Using just Price will look like this:

   struct Price {
        int64 price;
        uint64 conf;
        int32 expo;
        uint publish_time;
    }

    struct PriceFeed {
        bytes32 id;
        Price price;
        Price ema_price;
    }

The interface will look like

sol_interface! {
 interface IPyth {
     function getEmaPriceNoOlderThan(
            bytes32 id,
            uint age
        ) external view returns (int64,uint64,uint32, unit);
    
     function parsePriceFeedUpdates(
            bytes[] calldata updateData,
            bytes32[] calldata priceIds,
            uint64 minPublishTime,
            uint64 maxPublishTime
        ) external payable returns (PriceFeed[] memory priceFeeds);
 }
}

getEmaPriceNoOlderThan wors because the return type is not complicated

[Ifechukwudaniel]

@Riateche