iulspop Happy DOM Tests
Act as a top-tier software engineer with serious testing skills.
Write React component tests for: $ARGUMENTS
Each test must answer these 5 questions:
- What is the component under test? (test should be in a named describe block)
- What is the expected behavior? ($given and $should arguments are adequate)
- What props or state trigger the behavior? (use a factory function with defaults)
- What does the user see or interact with? (accessible queries, not implementation details)
- How can we find the bug? (implicitly answered if the above questions are answered correctly)
HappyDomTests {
Constraints {
Use Vitest with describe, expect, and test. Test files use the .test.tsx extension.
Tests must use the "given: ..., should: ..." prose format.
Colocate test files next to the component they test.
Import render, screen, userEvent, and createRoutesStub from a shared ~/test/react-test-utils module that wraps Testing Library with app providers (i18n, form context, etc.).
Create a props factory function per component with sensible defaults. Each test overrides only what it needs.
Use createRoutesStub from React Router to provide routing context. Pass initialEntries for specific routes.
Use accessible queries as the primary locator strategy: screen.getByRole, screen.getByLabel, screen.getByText.
Use screen.queryByRole (returns null) for negative assertions — never getByRole with not.toBeInTheDocument.
Use regex with case-insensitive flag for text matching: { name: /submit/i }.
Use userEvent.setup() for user interactions — never fireEvent.
Use vi.fn() for mock callbacks. Use vi.spyOn for global mocks.
Use renderHook and act for testing custom hooks. Use vi.useFakeTimers() for timer-based hooks.
Use @faker-js/faker and cuid2 in factories for realistic test data.
Use existing infrastructure factories (*-factories.server.ts) when props come from database entities.
Wrap RouterStub in additional providers (e.g. SidebarProvider) when the component requires them.
Pass hydrationData to RouterStub when the component reads loader data.
Use test.each for parametrized tests when multiple inputs produce similar outcomes.
Assert accessibility attributes: toHaveAttribute("aria-selected", "true"), toHaveAttribute("aria-current", "page").
Assert element state: toBeDisabled(), toBeEnabled(), toHaveFocus().
Assert structure: toBeInTheDocument(), toHaveAttribute("href", "/path"), toHaveTextContent(/text/i).
Capture actual and expected values in variables before asserting with toEqual for pure logic checks.
}
Boundaries {
Pure function tests without React (.test.ts) -> use /unit-tests instead
Database or server action tests (.spec.ts) -> use /integration-tests instead
Browser-level user flow tests (.e2e.ts) -> use /e2e-tests instead
This skill is for React component and hook render tests (.test.tsx) only.
}
}