fix: add route-level error boundary fallback (#120)

[mittalsonal]

Summary

• add a reusable route-level React ErrorBoundary component
• wrap the routed app so uncaught render failures fall back to a recovery UI instead of a white screen
• add a focused test covering the fallback render path

Verification

• npm test -- --runTestsByPath src/App.test.js --runInBand --watchAll=false
• npm run build
• git diff --check

[mittalsonal]

Please add the required gssoc:approved and difficulty/type labels when convenient so this counts correctly on the tracker. Recommended labels here: level:beginner, ype:bug.

[mittalsonal]

Verification completed locally:

• npm test -- --runTestsByPath src/App.test.js --runInBand --watchAll=false
• npm run build
• git diff --check

[entelligence-ai-pr-reviews]

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Confidence Score: 5/5 - Safe to Merge

Safe to merge — this PR introduces a route-level error boundary fallback (#120) and the automated review found zero issues across all three changed files. The implementation appears clean with no logic bugs, security concerns, or runtime hazards identified. All changed files received coverage and no pre-existing unresolved comments are carried forward.

Key Findings:

• All 3 changed files were reviewed and no issues of any severity were flagged — no missing null checks, no unsafe fallback rendering paths, and no error suppression anti-patterns detected.
• The PR's stated goal of adding a route-level error boundary fallback is a defensive, additive change that improves resilience rather than modifying existing logic, which reduces the risk of regression.
• No pre-existing unresolved review comments exist in this PR, meaning there is no accumulated technical debt or deferred concerns to consider.

[entelligence-ai-pr-reviews]

EntelligenceAI PR Summary

This PR enhances the ErrorBoundary component with dark theme styling, a refactored handler method, route-level error containment, and test coverage for fallback UI rendering.

• Added a second <ErrorBoundary> wrapping <Routes> in src/App.js for localized routing error handling
• Refactored ErrorBoundary.js error UI: dark background (#0f172a), light text (#e5e7eb), minHeight: '100vh', maxWidth: 32rem, and color: '#052e16' on the button
• Replaced inline onClick arrow function with a dedicated handleGoHome class method in ErrorBoundary.js
• Added a new test in src/App.test.js rendering an error-throwing child and asserting fallback UI content; Jest spy suppresses expected console.error calls

---

Confidence Score: 5/5 - Safe to Merge

Safe to merge — this PR cleanly adds a route-level <ErrorBoundary> wrapper in src/App.js and refactors ErrorBoundary.js with dark-theme styling, a bound handler method replacing the inline arrow function, and accompanying test coverage for fallback UI rendering. No review comments were generated across all three changed files, and the heuristic analysis found zero issues at any severity level. The changes are well-scoped: the second <ErrorBoundary> provides localized routing error containment without touching application logic, and the styling updates (dark background #0f172a, light text #e5e7eb, minHeight: '100vh') are cosmetic improvements with no runtime impact.

Key Findings:

• The addition of a second <ErrorBoundary> wrapping <Routes> in src/App.js is architecturally sound — it isolates routing errors from the top-level boundary, preventing a routing failure from taking down the entire application shell.
• Replacing the inline onClick arrow function with a bound class method in ErrorBoundary.js is a minor but correct refactor that avoids unnecessary re-creation of the handler on each render.
• Test coverage was added for the fallback UI rendering path, which is the most critical path in an ErrorBoundary component and is frequently left untested.
• No logic changes were made to the error catching or state reset mechanisms in ErrorBoundary.js, limiting the blast radius of this PR to styling and structural improvements.

Files requiring special attention

• src/App.js
• src/ErrorBoundary.js

[mittalsonal]

Rebased this PR on the latest master and resolved the conflicts while preserving the route-level ErrorBoundary fallback and test coverage.

Current status: mergeable and GitGuardian check is passing. Ready for review/merge when maintainers get a chance.