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react-testing-library skill

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This skill helps you write maintainable React Testing Library tests by applying best practices for queries, async handling, and user interactions.

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---
name: react-testing-library
description: React Testing Library best practices for writing maintainable, user-centric tests. Use when writing, reviewing, or refactoring RTL tests. Triggers on test files, testing patterns, getBy/queryBy queries, userEvent, waitFor, and component testing.
---

# React Testing Library Best Practices

Comprehensive testing guide for React components using Testing Library, designed for AI agents and LLMs. Contains 43 rules across 9 categories, prioritized by impact to guide test writing and code review.

## When to Apply

Reference these guidelines when:
- Writing new component tests with React Testing Library
- Selecting queries (getByRole, getByLabelText, etc.)
- Handling async operations in tests (findBy, waitFor)
- Simulating user interactions (userEvent)
- Reviewing tests for anti-patterns and implementation detail testing

## Rule Categories by Priority

| Priority | Category | Impact | Prefix |
|----------|----------|--------|--------|
| 1 | Query Selection | CRITICAL | `query-` |
| 2 | Async Handling | CRITICAL | `async-` |
| 3 | Common Anti-Patterns | CRITICAL | `anti-` |
| 4 | User Interaction | HIGH | `user-` |
| 5 | Assertions | HIGH | `assert-` |
| 6 | Component Setup | MEDIUM | `setup-` |
| 7 | Test Structure | MEDIUM | `struct-` |
| 8 | Debugging | LOW-MEDIUM | `debug-` |
| 9 | Accessibility Testing | LOW | `a11y-` |

## Quick Reference

### 1. Query Selection (CRITICAL)

- [`query-prefer-role`](references/query-prefer-role.md) - Prefer getByRole over other queries
- [`query-avoid-testid`](references/query-avoid-testid.md) - Avoid getByTestId as primary query
- [`query-use-screen`](references/query-use-screen.md) - Use screen for queries
- [`query-label-text-forms`](references/query-label-text-forms.md) - Use getByLabelText for form fields
- [`query-role-name-option`](references/query-role-name-option.md) - Use name option with getByRole
- [`query-get-vs-query`](references/query-get-vs-query.md) - Use getBy for present, queryBy for absent
- [`query-within-scope`](references/query-within-scope.md) - Use within() to scope queries

### 2. Async Handling (CRITICAL)

- [`async-findby-over-waitfor`](references/async-findby-over-waitfor.md) - Use findBy instead of waitFor + getBy
- [`async-await-findby`](references/async-await-findby.md) - Always await findBy queries
- [`async-single-assertion-waitfor`](references/async-single-assertion-waitfor.md) - Single assertion in waitFor
- [`async-no-side-effects-waitfor`](references/async-no-side-effects-waitfor.md) - Avoid side effects in waitFor
- [`async-waitfor-disappear`](references/async-waitfor-disappear.md) - Use waitForElementToBeRemoved

### 3. Common Anti-Patterns (CRITICAL)

- [`anti-unnecessary-act`](references/anti-unnecessary-act.md) - Avoid unnecessary act() wrapping
- [`anti-manual-cleanup`](references/anti-manual-cleanup.md) - Remove manual cleanup calls
- [`anti-implementation-details`](references/anti-implementation-details.md) - Avoid testing implementation details
- [`anti-empty-waitfor`](references/anti-empty-waitfor.md) - Avoid empty waitFor callbacks
- [`anti-container-queries`](references/anti-container-queries.md) - Avoid using container for queries
- [`anti-redundant-roles`](references/anti-redundant-roles.md) - Avoid adding redundant ARIA roles

### 4. User Interaction (HIGH)

- [`user-prefer-userevent`](references/user-prefer-userevent.md) - Use userEvent over fireEvent
- [`user-setup-before-render`](references/user-setup-before-render.md) - Setup userEvent before render
- [`user-await-interactions`](references/user-await-interactions.md) - Always await userEvent interactions
- [`user-keyboard-for-special-keys`](references/user-keyboard-for-special-keys.md) - Use keyboard() for special keys
- [`user-clear-before-type`](references/user-clear-before-type.md) - Use clear() before retyping

### 5. Assertions (HIGH)

- [`assert-jest-dom-matchers`](references/assert-jest-dom-matchers.md) - Use jest-dom matchers
- [`assert-visible-over-in-document`](references/assert-visible-over-in-document.md) - Use toBeVisible() for visibility
- [`assert-text-content`](references/assert-text-content.md) - Use toHaveTextContent() for text
- [`assert-have-value`](references/assert-have-value.md) - Use toHaveValue() for inputs
- [`assert-accessible-description`](references/assert-accessible-description.md) - Use toHaveAccessibleDescription()

### 6. Component Setup (MEDIUM)

- [`setup-wrapper-providers`](references/setup-wrapper-providers.md) - Use wrapper option for providers
- [`setup-custom-render`](references/setup-custom-render.md) - Create custom render with providers
- [`setup-mock-modules`](references/setup-mock-modules.md) - Mock modules at module level
- [`setup-fake-timers`](references/setup-fake-timers.md) - Configure userEvent with fake timers
- [`setup-render-hook`](references/setup-render-hook.md) - Use renderHook for testing hooks

### 7. Test Structure (MEDIUM)

- [`struct-arrange-act-assert`](references/struct-arrange-act-assert.md) - Follow Arrange-Act-Assert pattern
- [`struct-one-behavior-per-test`](references/struct-one-behavior-per-test.md) - Test one behavior per test
- [`struct-descriptive-names`](references/struct-descriptive-names.md) - Use descriptive test names
- [`struct-avoid-beforeeach-render`](references/struct-avoid-beforeeach-render.md) - Avoid render() in beforeEach

### 8. Debugging (LOW-MEDIUM)

- [`debug-screen-debug`](references/debug-screen-debug.md) - Use screen.debug() to inspect DOM
- [`debug-logroles`](references/debug-logroles.md) - Use logRoles to find available roles
- [`debug-testing-playground`](references/debug-testing-playground.md) - Use Testing Playground for queries

### 9. Accessibility Testing (LOW)

- [`a11y-role-queries-verify`](references/a11y-role-queries-verify.md) - Role queries verify accessibility
- [`a11y-verify-focus`](references/a11y-verify-focus.md) - Test focus management
- [`a11y-test-aria-states`](references/a11y-test-aria-states.md) - Test ARIA states and properties

## How to Use

Read individual reference files for detailed explanations and code examples:

- [Section definitions](references/_sections.md) - Category structure and impact levels
- [Rule template](assets/templates/_template.md) - Template for adding new rules

## Reference Files

| File | Description |
|------|-------------|
| [references/_sections.md](references/_sections.md) | Category definitions and ordering |
| [assets/templates/_template.md](assets/templates/_template.md) | Template for new rules |
| [metadata.json](metadata.json) | Version and reference information |

Overview

This skill provides React Testing Library best practices for writing maintainable, user-centric tests. It guides selection of queries, handling async behavior, simulating user interactions, and avoiding common anti-patterns to keep tests resilient and readable. Use it when authoring, reviewing, or refactoring RTL tests in TypeScript React projects.

How this skill works

The skill inspects test files and common testing patterns to identify opportunities to apply RTL rules: preferred queries (getByRole, getByLabelText), async handling (findBy, waitForElementToBeRemoved), and correct use of userEvent. It highlights anti-patterns such as implementation-detail assertions, overuse of getByTestId, unnecessary act() calls, and manual cleanup, and recommends concrete replacements and coding patterns.

When to use it

  • Writing new component tests to ensure queries and assertions are user-centric
  • Reviewing or refactoring existing tests to remove brittle implementation details
  • Handling asynchronous UI updates, network responses, or delayed DOM changes
  • Simulating user interactions like typing, clicking, and keyboard input
  • Configuring test setup: custom render wrappers, mocks, and fake timers

Best practices

  • Prefer getByRole and getByLabelText over getByTestId to mirror user behavior
  • Use screen.* queries and within() to scope searches instead of container queries
  • Await findBy queries for async elements and use waitForElementToBeRemoved for disappearances
  • Use userEvent (await interactions) instead of fireEvent for realistic events
  • Assert outcomes with jest-dom matchers (toBeVisible, toHaveTextContent, toHaveValue)
  • Follow Arrange-Act-Assert and test one behavior per test for clarity

Example use cases

  • Replacing getByTestId checks with getByRole(name) to improve accessibility verification
  • Refactoring tests that use waitFor + getBy to instead await findBy for simpler async handling
  • Configuring a custom render wrapper to provide context providers and reduce duplication
  • Converting fireEvent sequences to await userEvent calls to match real user timing
  • Using waitForElementToBeRemoved to assert a loading indicator disappears after fetch

FAQ

Why prefer getByRole over getByTestId?

getByRole reflects what a user interacts with and often includes accessible names; it makes tests more robust and verifies accessibility.

When should I use waitFor instead of findBy?

Use findBy for waiting for a single element to appear. Use waitFor for complex conditions or multiple assertions where findBy is insufficient.