feat: call "cleanup" automatically

src/__tests__/auto-cleanup.js

@@ -0,0 +1,34 @@
+import React from 'react';
+import { View } from 'react-native';
+import { render } from '..';
+
+let isMounted = false;
+
+class Test extends React.Component<*> {
+  componentDidMount() {
+    isMounted = true;
+  }
+
+  componentWillUnmount() {
+    isMounted = false;
+    if (this.props.onUnmount) {
+      this.props.onUnmount();
+    }
+  }
+  render() {
+    return <View />;
+  }
+}
+
+// This just verifies that by importing RNTL in an
+// environment which supports afterEach (like jest)
+// we'll get automatic cleanup between tests.
+test('first', () => {
+  const fn = jest.fn();
+  render(<Test onUnmount={fn} />);
+  expect(fn).not.toHaveBeenCalled();
+});
+
+test('second', () => {
+  expect(isMounted).toEqual(false);
+});

src/__tests__/cleanup.test.js

@@ -2,7 +2,7 @@
 /* eslint-disable react/no-multi-comp */
 import React from 'react';
 import { View } from 'react-native';
-import { cleanup, render } from '..';
+import { cleanup, render } from '../pure';
 
 class Test extends React.Component<*> {
   componentWillUnmount() {

src/__tests__/waitFor.test.js

@@ -55,6 +55,8 @@ test('waits for element until timeout is met', async () => {
   await expect(
     waitFor(() => getByText('Fresh'), { timeout: 100 })
   ).rejects.toThrow();
+
+  await waitFor(() => getByText('Fresh'));
 });
 
 test('waits for element with custom interval', async () => {

src/index.js

@@ -1,18 +1,17 @@
-// @flow
-import act from './act';
-import cleanup from './cleanup';
-import fireEvent from './fireEvent';
 import flushMicrotasksQueue from './flushMicrotasksQueue';
-import render from './render';
-import shallow from './shallow';
-import waitFor, { waitForElement } from './waitFor';
-import within from './within';
+import { cleanup } from './pure';
 
-export { act };
-export { cleanup };
-export { fireEvent };
-export { flushMicrotasksQueue };
-export { render };
-export { shallow };
-export { waitFor, waitForElement };
-export { within };
+// If we're running in a test runner that supports afterEach
+// then we'll automatically run cleanup afterEach test
+// this ensures that tests run in isolation from each other
+// if you don't like this then either import the `pure` module
+// or set the RNTL_SKIP_AUTO_CLEANUP env variable to 'true'.
+if (typeof afterEach === 'function' && !process.env.RNTL_SKIP_AUTO_CLEANUP) {
+  // eslint-disable-next-line no-undef
+  afterEach(async () => {
+    await flushMicrotasksQueue();
+    cleanup();
+  });
+}
+
+export * from './pure';

src/pure.js

@@ -0,0 +1,18 @@
+// @flow
+import act from './act';
+import cleanup from './cleanup';
+import fireEvent from './fireEvent';
+import flushMicrotasksQueue from './flushMicrotasksQueue';
+import render from './render';
+import shallow from './shallow';
+import waitFor, { waitForElement } from './waitFor';
+import within from './within';
+
+export { act };
+export { cleanup };
+export { fireEvent };
+export { flushMicrotasksQueue };
+export { render };
+export { shallow };
+export { waitFor, waitForElement };
+export { within };

website/docs/API.md

@@ -123,6 +123,8 @@ const cleanup: () => void;
 
 Unmounts React trees that were mounted with `render`.
 
+> Please note that this is done automatically if the testing framework you're using supports the `afterEach` global (like mocha, Jest, and Jasmine). If not, you will need to do manual cleanups after each test.
+
 For example, if you're using the `jest` testing framework, then you would need to use the `afterEach` hook like so:
 
 ```jsx