Angular Upgrade Manual Testing Guide | Generated by AI
Question: If a frontend application is upgraded from Angular 9 to Angular 14, how should manual testing be performed, and what aspects of the app should we focus on?
Answer:
Upgrading from Angular 9 → 14 spans five major versions (10, 11, 12, 13, 14), so even when automated migrations (ng update) run successfully, many subtle and visual/behavioral regressions can appear. Manual exploratory testing becomes very important.
Recommended Manual Testing Approach
- Smoke test the entire application after the upgrade is stable (builds, starts, no console errors).
- Follow main user journeys end-to-end (happy paths + common error paths).
- Compare behavior side-by-side (old Angular 9 version vs new Angular 14 version) whenever possible.
- Use different browsers (Chrome, Firefox, Edge, Safari) — especially check mobile viewports / responsive design.
- Test with real data (staging environment, production-like data) — synthetic data often hides issues.
- Pay special attention to slow / data-heavy / animation-heavy screens.
- Record short screencasts of critical flows before & after upgrade — makes regression spotting much easier.
- Involve domain / business users in final UAT phase — developers often miss “feels wrong” issues.
Key Areas to Focus On During Manual Testing
| Priority | Area | What Exactly to Check / Common Breakage Points (9→14) | Why It Breaks Frequently |
|---|---|---|---|
| ★★★★★ | Routing & Navigation | • Deep linking • Back/forward browser buttons • Lazy-loaded modules load correctly? • Guards / resolvers • Auxiliary routes (if used) |
pathMatch defaults became stricter, resolver behavior changed, many router lifecycle tweaks |
| ★★★★★ | Forms (Template-driven + Reactive) | • Validation messages appear at correct time • Disabled / readonly state • Custom validators / async validators • Form value / status changes propagate correctly • Dirty / touched / pristine flags |
Angular 14 introduced much stricter typing → subtle coercion bugs surface |
| ★★★★☆ | Change Detection & Performance | • UI does not flicker / re-render unnecessarily • Infinite change detection loops (console warning) • Slow lists / large tables still usable? • Components inside *ngIf / ngSwitch update correctly |
Ivy + stricter change detection + new zone.js behaviors |
| ★★★★☆ | Templates & Directives | • Structural directives (*ngIf, *ngFor, *ngSwitch) • Custom structural / attribute directives • @Input / @Output bindings • Two-way bindings [(ngModel)] |
New template type checking is stricter, some old patterns are now warned / broken |
| ★★★★☆ | HTTP / Interceptors / API calls | • All HTTP calls still work • Interceptors modify / catch errors correctly • Loading spinners / disabled states during requests • Error handling UI (toast, modal, inline) |
HttpClient changes + RxJS updates (v6 → v7) |
| ★★★★☆ | Third-party libraries & Components | • Angular Material → check theme, typography, density • Charts (ng2-charts, highcharts-angular…) • Tables (ag-grid, prime-ng, material table) • Modals / dialogs / overlays • Date pickers / file upload components |
Many libs had major version jumps + breaking changes |
| ★★★☆☆ | Animations & Transitions | • Enter / leave animations • Route animations • @.disabled / :increment / :decrement |
Animation DSL had fixes & deprecations |
| ★★★☆☆ | Internationalization (i18n) | • Translations still load • Plural / gender rules correct • RTL languages (if supported) |
i18n tooling & extraction improved → old extraction can break |
| ★★★☆☆ | Accessibility (a11y) | • Screen reader behavior • Focus management (modals, menus) • Keyboard navigation • ARIA attributes |
Some old patterns are now flagged by extended diagnostics |
| ★★★☆☆ | Browser Console & Warnings | • No red errors • No yellow deprecation / Ivy / zone.js warnings • No “ExpressionChangedAfterItHasBeenCheckedError” |
Many old patterns now produce warnings |
| ★★☆☆☆ | Build & Bundle Size | • Application still loads reasonably fast • No huge regressions in bundle size |
Ivy + differential loading changes + tree-shaking improvements |
| ★★☆☆☆ | Edge Cases | • Empty states • Very long content / overflow • Very large forms / lists • Offline mode (if implemented) • Copy-paste / drag-drop features |
Often not covered by unit tests |
Quick Checklist Summary for Testers
- Login / authentication flows (including social login if any)
- Main navigation + sidebar / topbar
- CRUD operations on main entities
- Search / filtering / sorting
- Form submission + validation
- File upload / download (if exists)
- Any real-time / polling / websocket features
- Export to Excel/PDF
- Responsive design on phone/tablet/desktop
- Browser back/forward/refresh behavior
Follow the official Angular Update Guide (https://angular.dev/update-guide) and read release notes / breaking changes summaries for versions 10–14.
Careful manual testing + good before/after comparison is usually the difference between “it works on my machine” and “production is broken”.
References:
- Angular Update Guide
- Angular 14 Release Notes & Breaking Changes Discussion (look for v10 to v14 sections)