Adding the Testing Infrastructure (Vitest)

[Slambot01]

Problem

The project currently has 0% test coverage. I verified there are no .test. or .spec. files in the codebase. This means no automated way to catch regressions, verify refactors, or validate PR changes.

Proposed solution

Set up Vitest testing infrastructure with initial coverage for core modules.

Implementation:

1. Configure Vitest + React Testing Library + happy-dom
2. Write 50+ unit tests for:
   • src/robotoff.ts (API client)
   • src/off.ts (Open Food Facts API)
   • src/utils.ts (utilities)
3. Add GitHub Actions workflow for CI testing
4. Create TESTING.md documentation

Why Vitest: Vite-native (already using Vite), faster than Jest, compatible API.

Additional context

Deliverables:

• vitest.config.ts configuration
• 50+ test files
• .github/workflows/test.yml CI workflow
• Testing documentation

Timeline: 3-4 days

Design & mockups

N/A - Infrastructure contribution

[LakshuCodes]

Hi ,
I would like to work on this issue.
Could you please assign it to me?