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2.8 KiB
ADR 004: Comprehensive Component-Level Testing with Shared Helpers
Status: Accepted
Date: 2026-03-05
Deciders: Development Team
Context
The plugin has extensive test coverage including both unit tests (k8s.ts, KubeVipDataContext) and component render tests (ConfigPage, NodesPage, OverviewPage, ServiceDetailSection, ServicesPage). Component tests need to mock both Headlamp's API and CommonComponents.
A shared test-helpers.tsx file provides fixture factories, and a __mocks__/commonComponents.ts file provides stub implementations of Headlamp's CommonComponents for render testing.
Decision
Implement comprehensive component-level testing with two shared test infrastructure files:
test-helpers.tsx: Shared fixture factories for creating test data (mock Services, Nodes, Pods, DaemonSets, ConfigMaps, Leases). Provides consistent test data across all test files.__mocks__/commonComponents.ts: Stub implementations of Headlamp CommonComponents (SectionBox,SimpleTable,StatusLabel,NameValueTable) that render as simple HTML elements for testing.
All component tests render with a KubeVipDataProvider wrapper using mocked context values, verifying the component renders correct data from context.
Consequences
Positive
- ✅ Consistent test fixtures across all test files eliminate divergent test data
- ✅ CommonComponents mocks enable render testing without the full Headlamp runtime
- ✅ Comprehensive coverage of component rendering logic and context integration
- ✅ Easy to add new component tests by reusing existing fixtures and mocks
Negative
- ⚠️ Mock maintenance burden when Headlamp's CommonComponents API changes
- ⚠️ Test helpers may diverge from actual API shapes over time if not kept in sync
These negatives are mitigated by type-checking test helpers against the actual interfaces, ensuring compile-time detection of API shape mismatches.
Alternatives Considered
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Unit tests only (no component rendering) — Rejected. Misses rendering bugs and context integration issues that only surface when components are mounted with real context values.
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E2E tests only — Rejected. Too slow for rapid development feedback and requires a running Headlamp instance with a connected cluster.
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Inline mocks per test file — Rejected. Leads to inconsistent and duplicated test setup across files, making it harder to maintain and update when APIs change.
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Storybook for component testing — Rejected. Additional tooling overhead is not justified for the scope of this plugin, and Storybook does not easily integrate with Headlamp's plugin component model.
Changelog
| Date | Change |
|---|---|
| 2026-03-05 | Initial decision recorded |