Revisa: Business Rules That Survive Code Changes

Revisa improves regression testing and application maintenance. When developers change code, they need to check that important business rules still work. Manual checking takes time and makes mistakes easy to miss. Revisa brings the business rule, IBM Bob’s proposed repair, and independent checks into one workflow. A small mistake can have real consequences. An app might refund more money than a customer paid, sell stock that is unavailable, or save a sale without recording its matching event. Revisa helps developers find and review these problems through a working sales demonstration. The workspace supports creating sales, changing quantities, issuing refunds, and adding stock. It checks three rules: every saved sale needs a matching event, total refunds cannot exceed the original payment, and stock cannot fall below zero. Users can interact with the workspace and see invalid actions get blocked. Users can also explore deliberately broken examples and ask IBM Bob to explain the issue or propose a repair. The backend sends Bob Shell the relevant source files and business rule. Bob returns its explanation or proposed change, which stays in a separate copy. Revisa then checks the proposal. Sale-event repairs receive a static source check that detects writes which bypass event recording. Refund and inventory repairs provide a proposed JSON policy to trusted application code, which tests the business rules. Revisa never executes generated JavaScript or automatically changes the live app. In our recorded example, IBM Bob identified a refund policy that checked each refund against the original payment instead of the remaining refundable amount. Bob proposed a correction, and Revisa tested it against four behavioral checks. All four passed. The developer could review the proposed change and download the results without changing the live workspace. This workflow brings together steps that a developer would otherwise need to coordinate: preparing an example, requesting a repair, checking the result, and collecting evidence. Users can download a readable PDF report or export the detailed JSON record. Recorded before, repaired, and regressed examples also show the same guard catching a mistake when it returns. Revisa targets developers and small software teams maintaining business applications. Its strength is making the relationship between a written requirement, an AI proposal, and the verification result visible and understandable. The current prototype supports three predefined scenarios on a sample project. It runs on Railway with private backend credentials, separate browser sessions, and spending limits. Sample sales use browser memory and do not process real payments. Broader repository support and additional business workflows are future extensions.