document the safeTransfer self-flow branch in LibFlow.flowERC20 NatSpec

[thedavidmeister]

Summary

LibFlow.flowERC20 NatSpec only mentioned safeTransferFrom. The implementation also calls safeTransfer when from == address(this) (OZ transferFrom consumes allowance even when from == msg.sender, so the self-flow branch must use safeTransfer instead). NatSpec now states both branches and the reason for the asymmetry.

Closes #379.

Test plan

• NatSpec-only

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Enhanced documentation for ERC20 transfer operations with greater clarity on execution paths.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: fc2a29f4-0f49-4f27-83e2-c1137c3a5481

📥 Commits

Reviewing files that changed from the base of the PR and between ec7a7f7 and 7e5c79b.

📒 Files selected for processing (1)

• src/lib/LibFlow.sol

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Walkthrough

Updated NatSpec documentation for flowERC20 in LibFlow.sol to explicitly describe both ERC20 transfer code paths: IERC20.safeTransferFrom when from == msg.sender and IERC20.safeTransfer when from == address(this), clarifying allowance and revert handling. No logic changes.

Changes

ERC20 Transfer Documentation

Layer / File(s)	Summary
flowERC20 NatSpec clarification src/lib/LibFlow.sol	The flowERC20 function NatSpec comments are expanded to document both ERC20 transfer branches: IERC20.safeTransferFrom(from, to, amount) when the source is msg.sender (avoiding allowance overhead for self-initiated transfers) and IERC20.safeTransfer(to, amount) when the source is address(this) (contract-held tokens), with explicit notation that both branches surface token reverts.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely describes the main change: updating NatSpec documentation for the safeTransfer self-flow branch in LibFlow.flowERC20, which aligns perfectly with the changeset.
Linked Issues check	✅ Passed	The pull request successfully addresses issue #379 by updating the NatSpec to document both ERC20 transfer branches (safeTransferFrom and safeTransfer) and explains the rationale for the asymmetry.
Out of Scope Changes check	✅ Passed	All changes are scoped to updating NatSpec documentation in src/lib/LibFlow.sol with no executable logic modifications, remaining within the documented objectives.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch 2026-05-07-issue-379-libflow-erc20-natspec

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[thedavidmeister]

Reviewed 7e5c79b: document the safeTransfer self-flow branch in LibFlow.flowERC20 NatSpec — rebased onto main (test-only union conflict resolution + forge fmt), all checks green. LGTM.