Explain liquidation status better post-withdrawing rewards

[nicholaspai]

Once a liquidation has expired and the liquidator has withdrawn rewards, the liquidation will be deleted because there are no rewards for other parties remaining. However, the liquidator bot incorrectly translates the ensuing state (state gets reset to 0 once a liquidation is deleted) as "Dispute Failed".

The subtlety here is that after calling withdrawLiquidation() on EITHER a failed-disputed-liquidation OR an expired-liquidation, the state will get set to 0:

See this incorrect log message's "liquidation status" value for example:

Corrected log message here:

Signed-off-by: Nick Pai npai.nyc@gmail.com

[coveralls]

Coverage remained the same at 92.73% when pulling f1bbc7f on npai/liquidator-messaging-fix into 2333de6 on master.

[chrismaree]

Great catch & fix! Modifying this scruct does effects anything else as this specific implementation is the only place we use PostWithdrawLiquidationRewardsStatusTranslations right?

As an aside, it looks like the output in the slack message has larger spaces between line items. This is due to my most recent PR that updated the slack transport and how is spreads objects. In this context I'm not a huge fan of this. what do you think?

[nicholaspai]

Great catch & fix! Modifying this scruct does effects anything else as this specific implementation is the only place we use PostWithdrawLiquidationRewardsStatusTranslations right?

As an aside, it looks like the output in the slack message has larger spaces between line items. This is due to my most recent PR that updated the slack transport and how is spreads objects. In this context I'm not a huge fan of this. what do you think?

I also don't like the large spaces between items, the entire message is too spread out now and takes up too much screen space.

[nicholaspai]

Made a small change to this PR: I removed the post-withdraw messaging for Liquidation status == 1 because this is impossible. After the liquidator/sponsor/disputer successfully calls withdrawLiquidation() the LiquidationStatus can ONLY be 0 or 3. If the Dispute failed or the liquidation expired without dispute (i.e. status 4 and 1 respectively), then the Liquidation will get deleted and the status will go to 0. If the Dispute succeeded (i.e. status 3), then it can stay at 3. If the Liquidation is pending dispute (i.e. status 2), then withdrawLiquidation() will fail.

For reference:

// States for an EMP's Liquidation to be in.
const LiquidationStatesEnum = {
  UNINITIALIZED: "0",
  PRE_DISPUTE: "1",
  PENDING_DISPUTE: "2",
  DISPUTE_SUCCEEDED: "3",
  DISPUTE_FAILED: "4"
};

// Maps the `liquidationStatus` property in the `LiquidationWithdrawn` event to human readable statuses.
// Note that these are status translations AFTER a withdrawLiquidation method is called
const PostWithdrawLiquidationRewardsStatusTranslations = {
  "0": "Liquidation deleted; All rewards have been withdrawn",
  "3": "Dispute succeeded; Not all rewards have been withdrawn"
  // @dev: Post `withdrawLiquidation()`, the status cannot be "2:PendingDispute", "1:PreDispute" or "4:DisputeFailed"
  // @dev: If a liquidation has expired (i.e. is pre-dispute) or a dispute has failed, then the first withdrawLiquidation() call will delete the liquidation
  // and reset its state to 0.
};

[mrice32]

LGTM!