Stake-pool list can return pools without cost, margin and pledge

[PegasusPool]

Context

The Pegasus app crashed when processing the pools from cardano-wallet on "Shelley Testnet 2".
After investigating I realised that some pools have missing fields that I never expected to be null.

Query:
cardano-wallet-shelley stake-pool list --port 3102 --stake 1

Response:

...
    {
        "metrics": {
            "saturation": 1.4277020904353006,
            "non_myopic_member_rewards": {
                "quantity": 0,
                "unit": "lovelace"
            },
            "produced_blocks": {
                "quantity": 0,
                "unit": "block"
            },
            "relative_stake": {
                "quantity": 0.57,
                "unit": "percent"
            }
        },
        "id": "e0850a4319f3b75f4df3be01e30fb1f0e9840b71c0d7251c01bd5997"
    }
...

Information	Cardano-node
Version	1.15.1 712a287602797e8fd889fbf73e56a08c3d8b004a
Platform	Ubuntu 18.04
Installation	Source

Information	Cardano-wallet
Version	2020.7.6 (git revision: 42872e)
Platform	Ubuntu 18.04
Installation	Source

Expected behavior

Pools always have cost, margin and pledge value populated when stake-pool list is fetched

Actual behavior

Some stake pools have no cost, margin and pledge value

Issue Update

After deleting cardano-wallet's DB folder and restarting the wallet the pool with id e0850a4319f3b75f4df3be01e30fb1f0e9840b71c0d7251c01bd5997 is now showing up with cost, margin and pledge.

[KtorZ]

Pools information are fetched from 3 different places (ledger state, on-chain data and metadata server). It is utterly complicated / not desirable to maintain these three data-sources in sync. The pool cost, margin and pledge comes from on-chain certificates that are eventually read discovered. Yet, if you query the API right before they are, the wallet may not yet know about them but still know about pools via the ledger state queried from the node.

This is why these fields are marked as non-required in the API documentation. Though, once they are known, they will remain known.

I agree that the experience may not be the best one here, and there's no certainty that this will change anytime soon. Possibly, we could discard data received from the ledger state if the wallet hasn't yet discovered the corresponding certificate.

[PegasusPool]

Thanks for the explanation @KtorZ
I'll deal with this in the app now and hope your proposal to discard data received from the ledger in the absence of a certificate will be implemented at some point.

[KtorZ]

Should be fixed in latest master now.

Fixed as in: pools will only be returned with cost, margin and pledge.

[piotr-iohk]

lgtm