M-H11: reject issuance of receiver state during escrow ops

[philanton]

Description

When a sender submits a TransferSend, the node automatically enters the receiver-side path and calls issueTransferReceiverState. That function creates and stores a new TransferReceive state for the receiver’s channel, even if the receiver’s latest signed state is already in an escrow phase such as MutualLock or EscrowLock. As a result, an inbound transfer still advances the receiver’s channel state while the receiver is in the middle of a suspended escrow flow.
That breaks the normal completion path when the receiver later tries to complete the escrow flow.

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Added validation to reject release or transfer operations when the receiver has an active escrow lock, with appropriate error messaging.

• Tests

  • Added test cases to validate error handling for escrow lock scenarios in both app session and channel operations.

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 01a18000-c3e3-4a69-bd04-b324f4872400

📥 Commits

Reviewing files that changed from the base of the PR and between da44862 and 5e7aa84.

📒 Files selected for processing (4)

• clearnode/api/app_session_v1/handler.go
• clearnode/api/app_session_v1/submit_app_state_test.go
• clearnode/api/channel_v1/handler.go
• clearnode/api/channel_v1/submit_state_test.go

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📝 Walkthrough

Walkthrough

The changes introduce early validation in release-receiver-state issuance logic across two API handlers. When a last signed state has a non-nil EscrowChannelID, the functions now return an error immediately instead of conditionally skipping signing based on transition types. Two test cases validate this rejection behavior.

Changes

Cohort / File(s)	Summary
Handler Logic Updates clearnode/api/app_session_v1/handler.go, clearnode/api/channel_v1/handler.go	Replaced flag-based signing decision with early-exit validation. When lastSignedState has non-nil EscrowChannelID, handlers now return RPC error immediately instead of continuing. Removed conditional signing suppression based on lock transition types.
Test Coverage clearnode/api/app_session_v1/submit_app_state_test.go, clearnode/api/channel_v1/submit_state_test.go	Added two new test cases validating rejection behavior: TestSubmitAppState_WithdrawIntent_ReceiverWithEscrowLock_Rejected and TestSubmitState_TransferSend_ReceiverWithEscrowLock_Rejected. Each verifies error response when receiver's last signed state contains active escrow lock.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Suggested reviewers

• dimast-x
• ihsraham

Poem

🐰 A lock so strong, escrow's guard,
Now caught before the signing card!
Early exit, swift and clean,
The finest validation ever seen.
hop hop ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly summarizes the main change: rejecting receiver state issuance during escrow operations, which matches the core logic alteration across both handler files.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/clearnode-h-10

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[nksazonov]

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