Visual Sentinel is an automated Visual Regression Testing (VRT) system built with Playwright and Percy. It provides a safety net for modern web applications by ensuring that visual integrity is preserved across deployments.
Traditional functional tests often pass even when the UI is visually broken — misaligned elements, broken CSS, or layout shifts can slip through unnoticed. Visual Sentinel solves this by comparing UI snapshots against a trusted baseline, automatically detecting differences and highlighting them before they reach production.
Visual Sentinel ensures continuous visual assurance for enterprise applications:
- Baseline Creation: The first run establishes a "visual truth" for key pages such as login and dashboard.
- Snapshot Comparison: On subsequent runs, Percy compares new snapshots against the baseline.
- Automated Alerts: Any differences are flagged, with highlighted diffs available in the Percy dashboard.
- CI/CD Integration: GitHub Actions ensures these checks run automatically on every commit or pull request.
This approach guarantees UI consistency, brand integrity, and user experience across environments.
Percy is the visual intelligence engine behind Visual Sentinel. Its role is critical:
- Snapshot Storage & Management: Securely stores baseline snapshots and organizes them across builds.
- Visual Diff Highlighting: Highlights differences directly in the dashboard for quick resolution.
- Workflow Integration: Works seamlessly with Playwright and GitHub Actions.
- Enterprise Scalability: Supports multiple projects, environments, and teams.
Percy ensures that enterprises can scale visual testing without sacrificing speed or accuracy.
| Technology | Role |
|---|---|
| Playwright | Browser automation, test execution, and page interaction |
| Percy.io | Visual comparison engine, snapshot storage, diff highlighting |
| Node.js/npm | Project environment and dependency management |
| GitHub Actions | Continuous Integration (CI) service for automated execution |
| JavaScript | Test scripting language |
Visual Sentinel is designed with scalability and enterprise adoption in mind:
- Consistency Across Deployments: Protects brand integrity by catching visual bugs before production.
- Cross-Browser & Multi-Viewport Testing (Future Enhancement): Expands coverage to different browsers and screen resolutions.
- Component-Level Targeting (Future Enhancement): Allows focused snapshot testing of specific UI components.
- End-to-End Flow Coverage (Future Enhancement): Extends visual checks to entire workflows.
- Scalable Reporting & Governance: Integrates Percy build reports into GitHub PRs for enterprise-wide enforcement.
- Reduced Risk: Prevents costly UI regressions that damage user trust.
- Faster Delivery: Automates visual checks, reducing manual QA effort.
- Scalability: Expands across multiple applications, teams, and environments.
- Professional-Grade Quality: Provides actionable insights with visual diffs.
- Developer Commit/PR → Code changes are pushed or a pull request is opened.
- GitHub Actions CI/CD → The pipeline installs dependencies, sets up browsers, and runs tests.
- Playwright Execution → Automated browser tests are executed on target pages.
- Percy Snapshot Capture → Percy takes snapshots of the UI during test runs.
- Baseline Comparison → Percy compares snapshots against the stored baseline.
- Visual Diff Reporting → Any differences are highlighted in the Percy dashboard.
- PR Status Check → GitHub integrates Percy results, enforcing visual quality gates before merging.
This workflow ensures that every commit is visually verified before it reaches production.
visual-sentinel/
├── .github/
│ └── workflows/
│ └── main.yml # GitHub Actions CI/CD workflow
├── tests/
│ └── visual.spec.js # Playwright test file with Percy snapshots
├── package.json # Project dependencies and scripts
└── README.md # Project documentation
- Mukul Dev Mahato
Visual Sentinel is more than a testing tool—it’s a visual safety net for enterprises. By combining Playwright’s automation with Percy’s powerful visual comparison engine, it ensures that every deployment maintains the highest standards of UI quality, consistency, and brand trust.