FrontendKnowledgeIndex

Frontend Knowledge Base

Human-facing index for frontend troubleshooting and test fixes.

Fix Guides

Document	Description
Act Warnings	React act(...) warnings from async state updates in tests. Wrapping renders in act() for Transitioner, Carbon components, and AuthProvider.
Async Test Isolation	Multiple elements found due to unawaited async render helper leaking DOM between Vitest tests.
Carbon ComboBox	How to properly interact with IBM Carbon's ComboBox in Vitest plus Testing Library. CustomEvent dispatch works only on the input node; prefer real userEvent.
No Node Access	Replace DOM traversal like .closest('form') and document.querySelector() with semantic queries. Covers getByTestId gotchas with Carbon wrappers.
Prefer User Event	Replace fireEvent with @testing-library/user-event for realistic browser event sequences.
Frontend Verification and Tooling	Vitest skips typechecking (run both tsc configs), zsh breaks unquoted ESLint file lists, stale Playwright dev servers fail e2e at login, and Lombok LSP noise.
TanStack Form Subscription	useForm does not re-render the owning component. Subscribe with a narrow useSelector(form.store, ...) to read form values reactively.

Pattern Guides

Document	Description
Test Patterns — Block Creation Wizard	Dirty-tab guard, scoped query cache, create stub, and cancellation test patterns.
Test Patterns — Formula Create Screen	Patterns for FormulaConfigurationCreateForm coverage improvement: Carbon RadioButtonGroup mocking in jsdom, TanStack Form setFieldValue re-render handling, Carbon Button submit workaround, multiple identical test IDs, and FormulaInput mock pattern.
Carbon React Grid and Subgrid Layouts	Responsive Carbon spans, scoped generated-grid styling, field grouping, and browser geometry checks.

Testing Library Lint Fixes

• testing-library/prefer-user-event — Replace fireEvent with @testing-library/user-event
• testing-library/no-node-access — Replace DOM traversal with semantic queries
• testing-library/act-warnings — Wrap async state updates from test router, Carbon, and AuthProvider in act()