Better error messages for invalid user actions in demo

[GeorgeFlerovsky]

For example:

• CLI action taken on wrong time
  • If a bidder tries to submit a bid when bidding hasn't started: "Cannot submit bid: bidding has not started yet. Bidding should start in 19s."
  • If a bidder tries to submit a bid when bidding has ended: "Cannot submit bid: bidding has ended 33s ago."
  • If a bidder tries to buy the auction lot: "Cannot buy auction lot yet: bidding will end in 2m14s."
  • If the seller tries to reclaim the auction lot: "Cannot reclaim auction lot yet: voucher will expire in 52s."
• A bidder tries to buy the auction lot but he isn't the winning bidder: "Cannot buy auction lot: the winning bidder is someone else."

[uhbif19]

@GeorgeFlerovsky You mean the scope is only timing issues? Then we need to rephrase the title I think.

[GeorgeFlerovsky]

@GeorgeFlerovsky You mean the scope is only timing issues? Then we need to rephrase the title I think.

Yes, I think it's mostly just about timing issues. Although, we may also want to add error messages like this:

• If a bidder tries to buy the auction lot but he isn't the winning bidder: "Cannot buy auction lot: the winning bidder is someone else."

[uhbif19]

@GeorgeFlerovsky This issue is related: https://github.com/mlabs-haskell/hydra-auction/issues/44

[GeorgeFlerovsky]

@GeorgeFlerovsky This issue is related: https://github.com/mlabs-haskell/hydra-auction/issues/44

I would differentiate between the two:

1. User errors
2. System errors

[uhbif19]

@GeorgeFlerovsky #44 is about user errors too. Then you provide wrong nonce UTxO or taking some step then no proper UTxOs for that step is present.

[uhbif19]

As for code, I think that creating some AuctionTimeframe datatype may be usable. Like we can associate them to intervals with function and check them uniformingly. Maybe we can even share code with OnChain.

[GeorgeFlerovsky]

@GeorgeFlerovsky #44 is about user errors too. Then you provide wrong nonce UTxO or taking some step then no proper UTxOs for that step is present.

Actually, for the demo, I would like to remove the need for the CLI user to specify the nonce utxo. (Maybe this should be a separate GH issue)

It would be cleaner to:

• Search the user's utxos for the "Mona Lisa" token.
• Set the utxoNonce to be the TxOutRef of the utxo that contains the token.
• If the user doesn't have the token, then give a user error 'Selected user doesn't have the "Mona Lisa" token.This demo is configured to use this token as the auction lot.'

The more general mechanism to select arbitrary auction lot tokens will be needed in production, but it's kind of irrelevant to our development for now. On the other, requiring users to copy-paste utxo refs in CLI is really ugly UX — reminds me of the early Alonzo days.

When we do need this general functionality in the future, we'll probably be replacing the CLI interface with a wallet-based web interface, which has a better UX for selecting tokens/utxos.

[uhbif19]

The more general mechanism to select arbitrary auction lot tokens will be needed in production, but it's kind of irrelevant to our development for now.

We can just make nonce CLI param optional and have both.

On the other, requiring users to copy-paste utxo refs in CLI is really ugly UX — reminds me of the early Alonzo days.

For now I feel searching for UTxO automatically hides the real thing too much.

[uhbif19]

@GeorgeFlerovsky @nazrhom

Not sure where better to place time check. I can place checks it in CLI actions separately or in check inside Tx.* functions and return error using Either.

[GeorgeFlerovsky]

@GeorgeFlerovsky @nazrhom

Not sure where better to place time check. I can place checks it in CLI actions separately or in check inside Tx.* functions and return error using Either.

Time checking should be done in CLI actions. We're basically simulating how the frontend web UI would tell a user that certain actions are not available at a particular time (e.g. by graying out the buttons).