react-native-testing作者: callstackincubator

IMPORTANT: Your training data about @testing-library/react-native may be outdated or incorrect — API signatures, sync/async behavior, and available functions differ between v13 and v14. Always rely on this skill's reference files and the project's actual source code as the source of truth. Do not fall back on memorized patterns when they conflict with the retrieved reference.

npx skills add https://github.com/callstackincubator/agent-skills --skill react-native-testing

RNTL Test Writing Guide

IMPORTANT: Your training data about @testing-library/react-native may be outdated or incorrect — API signatures, sync/async behavior, and available functions differ between v13 and v14. Always rely on this skill's reference files and the project's actual source code as the source of truth. Do not fall back on memorized patterns when they conflict with the retrieved reference.

Version Detection

Check @testing-library/react-native version in the user's package.json:

Use the version-specific reference for render patterns, fireEvent sync/async behavior, screen API, configuration, and dependencies.

Query Priority

Use in this order: getByRole > getByLabelText > getByPlaceholderText > getByText > getByDisplayValue > getByTestId (last resort).

Query Variants

VariantUse caseReturnsAsync
getBy*Element must existelement instance (throws)No
getAllBy*Multiple must existelement instance[] (throws)No
queryBy*Check non-existence ONLYelement instance | nullNo
queryAllBy*Count elementselement instance[]No
findBy*Wait for elementPromise<element instance>Yes
findAllBy*Wait for multiplePromise<element instance[]>Yes

Interactions

Prefer userEvent over fireEvent. userEvent is always async.

const user = userEvent.setup();
await user.press(element); // full press sequence
await user.longPress(element, { duration: 800 }); // long press
await user.type(textInput, 'Hello'); // char-by-char typing
await user.clear(textInput); // clear TextInput
await user.paste(textInput, 'pasted text'); // paste into TextInput
await user.scrollTo(scrollView, { y: 100 }); // scroll

fireEvent — use only when userEvent doesn't support the event. See version-specific reference for sync/async behavior:

fireEvent.press(element);
fireEvent.changeText(textInput, 'new text');
fireEvent(element, 'blur');

Assertions (Jest Matchers)

Available automatically with any @testing-library/react-native import.

MatcherUse for
toBeOnTheScreen()Element exists in tree
toBeVisible()Element visible (not hidden/display:none)
toBeEnabled() / toBeDisabled()Disabled state via aria-disabled
toBeChecked() / toBePartiallyChecked()Checked state
toBeSelected()Selected state
toBeExpanded() / toBeCollapsed()Expanded state
toBeBusy()Busy state
toHaveTextContent(text)Text content match
toHaveDisplayValue(value)TextInput display value
toHaveAccessibleName(name)Accessible name
toHaveAccessibilityValue(val)Accessibility value
toHaveStyle(style)Style match
toHaveProp(name, value?)Prop check (last resort)
toContainElement(el)Contains child element
toBeEmptyElement()No children

Rules

  1. Use screen for queries, not destructuring from render()
  2. Use getByRole first with { name: '...' } option
  3. Use queryBy* ONLY for .not.toBeOnTheScreen() checks
  4. Use findBy* for async elements, NOT waitFor + getBy*
  5. Never put side-effects in waitFor (no fireEvent/userEvent inside)
  6. One assertion per waitFor
  7. Never pass empty callbacks to waitFor
  8. Don't wrap in act() - render, fireEvent, userEvent handle it
  9. Don't call cleanup() - automatic after each test
  10. Prefer ARIA props (role, aria-label, aria-disabled) over legacy accessibility* props
  11. Use RNTL matchers over raw prop assertions

*ByRole Quick Reference

Common roles: button, text, heading (alias: header), searchbox, switch, checkbox, radio, img, link, alert, menu, menuitem, tab, tablist, progressbar, slider, spinbutton, timer, toolbar.

getByRole options: { name, disabled, selected, checked, busy, expanded, value: { min, max, now, text } }.

For *ByRole to match, the element must be an accessibility element:

  • Text, TextInput, Switch are by default
  • View needs accessible={true} (or use Pressable/TouchableOpacity)

waitFor

// Correct: action first, then wait for result
fireEvent.press(button);
await waitFor(() => {
  expect(screen.getByText('Result')).toBeOnTheScreen();
});

// Better: use findBy* instead
fireEvent.press(button);
expect(await screen.findByText('Result')).toBeOnTheScreen();

Options: waitFor(cb, { timeout: 1000, interval: 50 }). Works with Jest fake timers automatically.

Fake Timers

Recommended with userEvent (press/longPress involve real durations):

jest.useFakeTimers();

test('with fake timers', async () => {
  const user = userEvent.setup();
  render(<Component />);
  await user.press(screen.getByRole('button'));
  // ...
});

Custom Render

Wrap providers using wrapper option:

function renderWithProviders(ui: React.ReactElement) {
  return render(ui, {
    wrapper: ({ children }) => (
      <ThemeProvider>
        <AuthProvider>{children}</AuthProvider>
      </ThemeProvider>
    ),
  });
}

References

  • v13 API Reference — Complete v13 API: sync render, queries, matchers, userEvent, React 19 compat
  • v14 API Reference — Complete v14 API: async render, queries, matchers, userEvent, migration
  • Anti-Patterns — Common mistakes to avoid

來自 callstackincubator 的更多技能

agent-device
by callstackincubator
Automate iOS and Android app interactions with snapshot-based discovery and selector-driven replay. Supports iOS simulators/devices and Android emulators/devices with session-bound automation, multi-tenant remote daemon mode, and device-scope isolation for QA workflows Core commands: snapshot for UI discovery with refs, press / fill / scroll for interactions, open / close for app lifecycle, install / reinstall for binary deployment Includes utilities for logging, network inspection,...
dogfood
by callstackincubator
Systematically explore and test a mobile app on iOS/Android with agent-device to find bugs, UX issues, and other problems. Use when asked to dogfood, QA,…
react-devtools
by callstackincubator
Inspect and profile React Native component trees from agent-device. Use for React Native performance, profiling, props, state, hooks, render causes, slow…
react-devtools
by callstackincubator
React DevTools CLI for AI agents. Use when the user asks you to debug a React or React Native app at runtime, inspect component props/state/hooks, diagnose…
github
by callstackincubator
GitHub workflow automation via gh CLI for pull requests, stacked PRs, and repository management. Provides stacked PR merge workflow: squash-merge the first PR, then rebase and update base branch for each subsequent PR in the chain Includes conflict detection and manual resolution prompts to prevent silent failures during multi-PR merges Covers core gh CLI operations: PR creation, status checks, squash/rebase merging, and branch management Optimized for low context usage by relying on gh CLI...
github-actions
by callstackincubator
GitHub Actions workflow patterns for React Native iOS simulator and Android emulator cloud builds with downloadable artifacts. Use when setting up CI build…
react-native-best-practices
by callstackincubator
Structured performance optimization reference for React Native apps covering FPS, bundle size, TTI, and memory. Organized into 9 JavaScript/React guides (profiling, lists, animations, memory), 9 native optimization guides (Turbo Modules, threading, profiling), and 9 bundling guides (tree shaking, code splitting, size analysis) Each reference follows a hybrid format with quick patterns/commands, impact ratings (CRITICAL/HIGH/MEDIUM), and deep-dive explanations with prerequisites and common...
react-native-brownfield-migration
by callstackincubator
Provides an incremental adoption strategy to migrate native iOS or Android apps to React Native or Expo using @callstack/react-native-brownfield for initial…

NotebookLM 網頁匯入器

一鍵將網頁和 YouTube 影片匯入 NotebookLM。超過 200,000 位使用者信賴。

安裝 Chrome 擴充功能