Grounded iOS‑to‑Web Harness: Evidence‑Driven App Migration with Behavioral and Visual Verification

Description and use

Grounded iOS‑to‑Web Harness provides a systematic verification pipeline for migrating an iOS app to a React web app, covering screen coverage, behavioral fidelity, and visual similarity.

Problem

Migrating an iOS app to a React web app often leaves gaps: missing screens, altered behavior, or superficial visual similarity. These gaps are hard to audit when relying only on prompt‑based generation.

Outcome

All automated checks passed, with only a few visual states requiring review. The harness enabled systematic verification of screen coverage, behavior fidelity, and visual similarity, reducing reliance on manual inspection.

Workflow

• 1. Discover and reconcile source facts via static analysis, code‑memory, and runtime exploration.
• 2. Lock facts and generate compact per‑screen context for the coding agent.
• 3. Agent builds the React web app using the provided context.
• 4. Verify coverage: check for missing states, blank routes, broken images, fabricated data, and layout issues.
• 5. Verify behavior with Playwright: execute clicks, inputs, and cross‑page journeys against locked action facts.
• 6. Run critical‑state visual regression: compare iOS and web screenshots using Pixelmatch, SSIM, and regional diff.
• 7. Review flagged visual states and perform bounded repair if needed.
• 8. Conduct final human visual review before acceptance.

Evidence

The final result was accepted after human visual review. Six experimental visual states were still routed to “review recommended,” and the repository reports that honestly rather than turning SSIM into a false product-quality claim.

Source

41/41 Web checks passing, 40/40 Harness regression tests passing

Source