FLOW-12: Escrow Balance Events Missing on COA Processing

[liobrasil]

Severity: Informational

Files Affected

• solidity/src/FlowYieldVaultsRequests.sol

Description

In FlowYieldVaultsRequests.sol, escrow/refund balances are tracked in pendingUserBalances and are sometimes surfaced via the BalanceUpdated event, such as when _createRequest() credits escrow for CREATE_YIELDVAULT/DEPOSIT_TO_YIELDVAULT, and when cancelRequest(), dropRequests(), and claimRefund() adjust balances.

However:

• startProcessing() deducts pendingUserBalances[request.user][request.tokenAddress] for CREATE/DEPOSIT without emitting BalanceUpdated
• completeProcessing() can credit pendingUserBalances on failed CREATE/DEPOSIT refunds without emitting BalanceUpdated

As a result, event-driven indexers and UIs may not observe escrow/refund balance changes that occur during COA-driven lifecycle transitions unless they continuously read storage or implement custom inference logic.

Recommendation

Emit BalanceUpdated(request.user, request.tokenAddress, pendingUserBalances[request.user][request.tokenAddress]) after the escrow deduction in startProcessing() and after the refund credit in completeProcessing() for failed CREATE/DEPOSIT requests.

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Parent Issue: #15

[liobrasil]

Fixed via pull-based refund model refactor

The concern was that pendingUserBalances changes during COA processing lacked event coverage. This is now fixed by separating escrow tracking from refund tracking:

Architecture change:

• pendingUserBalances → only tracks escrowed funds for active pending requests
• claimableRefunds → new mapping for refunds from failed/cancelled requests

Event coverage is now complete:

Operation	Mapping	Event
Request created	pendingUserBalances ↑	BalanceUpdated
startProcessing()	pendingUserBalances ↓	BalanceUpdated
completeProcessing(false)	claimableRefunds ↑	RefundCredited
cancelRequest()	claimableRefunds ↑	RefundCredited
claimRefund()	claimableRefunds ↓	RefundClaimed

Event-driven indexers can now track both balances reliably.