Return a conflict when EF Core detects a stale order edit: Perch rule pack
1 saved requirement for ASP.NET Core. Inspect the selectors and adapt the example paths to your repository.
- name: stale-update-is-not-success
where: "Services/CancelOrder.cs"
ensure: >-
Apply must return false when SaveChangesAsync throws DbUpdateConcurrencyException. A stale write must not be reported as successful.
Download the rule pack ZIP · Download YAML · Agent repair task · Implementation, integration requirements and captured checks
Install the rule without replacing your configuration
npm install -g @lakeday/perch
perch login
curl -fL 'https://reporules.fyi/aspnet-core/optimistic-concurrency/rule-pack.zip' -o 'perch-guide-aspnet-core-optimistic-concurrency.zip'
unzip -n 'perch-guide-aspnet-core-optimistic-concurrency.zip'Keep your existing perch.yaml. Extraction preserves existing files and adds .perch/rules/perch-guide-aspnet-core-optimistic-concurrency.yaml. Review each where selector before running a check on your application.
Configure your coding agent
perch setup claude-code
perch setup codex
perch setup cursor
perch setup piChoose the setup command for the agent you use.
Check the edit, fix the finding, check again
perch check Services/CancelOrder.cs --rules stale-update-is-not-success --jsonRun the check after an agent edit. Read the finding and affected code, repair the implementation, and repeat the identical command. Keep the application regression tests as separate gates.
Exit 3 means a finding. Exit 1 or 2 means the check did not complete. A pass does not prove application correctness. Fresh judgments can vary; unchanged requests reuse cached answers. Relevant source is sent to the configured model service.