[Staking] query response should be Coins

[yun-yeo]

The staking delegation query response's rewards must be []Coin not Coin, https://github.com/cosmos/cosmos-sdk/blob/6a624c3f68900e99255846b4a63fb79285af54ce/x/distribution/types/query.go#L14

cosmwasm/packages/std/src/query.rs

Line 126 in c9a5141

pub amount: Coin,

[ethanfrey]

There are quite a few steps between this. And two calls for the delegations - simple and full.

Here is the full Delegation type in CosmWasm. This is returned from AllDelegations query which uses tokensFromShares to compute the number of bonded tokens.

This amount an only be a coin, as it must be the bonded denom (only one is allowed) and returns the total amount bonded.

However, digging down a bit more, there is a FullDelegation response, which does have an accumulated_rewards field, which is what you are looking for.

If you look into the go query handler, which calls into the Keeper to get the rewards. This is then transformed into the cosmwasm type to pass it into Rust. And should have the reward info.

Digging in, I see this was left as a TODO as I had no idea how to get such info from the staking module.

[ethanfrey]

I issue raised is not an issue but rather a confusion of the API. However, it did reveal two other issues (maybe we rename this issue or make new ones):

• FullDelegation.accumulated_rewards should be Vec<Coin> not Coins as the reward can be multiple Coins
• The implementation to calculate that was not done and needs to be implemented. Looking into this again, the calculation is done in distribution.Keeper.calculateDelegationRewards, which is a private method. Even the query method is private. And many of the functions used inside are private.

I am happy to modify the type of accumuated_rewards in CosmWasm, that is quite straightforward, but if you have any idea how I can get such information on rewards from the delegation module, please let me know.

[ethanfrey]

Replaced this with those two above issues: #515 and CosmWasm/wasmd#263

Thank you for reporting this and I would be grateful for any insights into CosmWasm/wasmd#263

[yun-yeo]

ok Thanks