Add issuer transfer expiry boundary tests for accept_issuer_transfer at exact ISSUER_TRANSFER_EXPIRY_SECS

[thlpkee20-wq]

Description

accept_issuer_transfer rejects with IssuerTransferExpired when now > timestamp + ISSUER_TRANSFER_EXPIRY_SECS, which is an exclusive comparison. The exact-boundary case (now == timestamp + expiry, which should still be accepted) and the saturating-add overflow case are untested. Add ledger-timestamp-controlled tests for these.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Relevant code: src/lib.rs (accept_issuer_transfer, propose_issuer_transfer, PendingTransfer)
• Use env.ledger().set_timestamp to drive the boundary

Suggested execution

• Fork the repo and create a branch
• git checkout -b feat/issuer-transfer-expiry-tests
• Implement changes
  • Propose, advance to exact expiry, assert accept succeeds
  • Advance one second past expiry, assert IssuerTransferExpired
  • Test timestamp.saturating_add near u64::MAX
• Validate security and correctness assumptions

Test and commit

• Run tests
  • cargo test
• Cover edge cases
  • Exact boundary, one-past, overflow saturation, self-transfer (new==old)
• Include test output and security notes

Example commit message

test: cover issuer transfer expiry boundary and overflow

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[meshackyaro]

@meshackyaro has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi, I'd like to work on this issue. I am a Software/Blockchain Engineer with experience building secure and scalable web systems/applications. I am comfortable working on the backend/smart contract side of applications, building secure working APIs. I can write various kinds of tests ranging from unit tests, fuzz tests, regression tests, integration tests, to even writing TDDs. I am fast with great problem solving and debugging skills.

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[drips-wave]

Congratulations, @meshackyaro! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

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