Task 4.10: Create Test Data Fixture for Reproducible Testing

[rowantervelde]

Epic: #11 (Epic 4: Edge Cases, Performance & Testing)
Type: Task
Priority: P1 (High)
Estimate: 0.5 day

Description

Create standardized test data fixture covering all edge cases to enable reproducible testing across unit, E2E, and manual tests.

Acceptance Criteria

• JSON fixture with 50+ articles covering all scenarios
• Include edge cases from testplan (TC-17):
  • 100+ articles (pagination)
  • Articles with missing titles/URLs
  • Extreme sentiment scores (0.99, -0.99)
  • Very long titles (>200 chars)
  • Unicode characters in titles
  • Duplicate articles
• Fixture includes metadata: timestamp, source distribution
• Load fixture in dev mode via /api/test/load-fixture endpoint
• Document fixture usage in README

Technical Notes

• Create tests/fixtures/sentiment-detail.json
• Structure: match /api/sentiment response format
• Include all 3 moods: positive, neutral, negative
• Add test helper: loadTestFixture() function
• Consider date ranges: ensure timestamps are recent
• Optionally: seed fixture into Netlify Blobs for E2E tests

Dependencies

• Blocks: Task 4.7 (Unit tests), Task 4.8 (E2E tests)
• Blocked by: None (can work in parallel)

Test Coverage

• Used by all test suites
• Manual testing with consistent data

Related Files

• tests/fixtures/sentiment-detail.json
• server/api/test/load-fixture.ts (optional dev endpoint)
• specs/004-sentiment-detail/testplan.md

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Part of Feature 004: Sentiment Detail Breakdown Page