'use strict';
let React;
let ReactNoop;
let Scheduler;
let act;
let waitFor;
let waitForAll;
let waitForPaint;
describe('StrictEffectsMode defaults', () => {
beforeEach(() => {
jest.resetModules();
React = require('react');
ReactNoop = require('react-noop-renderer');
Scheduler = require('scheduler');
act = require('internal-test-utils').act;
const InternalTestUtils = require('internal-test-utils');
waitFor = InternalTestUtils.waitFor;
waitForAll = InternalTestUtils.waitForAll;
waitForPaint = InternalTestUtils.waitForPaint;
});
it('should not double invoke effects in legacy mode', async () => {
const log = [];
function App({text}) {
React.useEffect(() => {
log.push('useEffect mount');
return () => log.push('useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect mount');
return () => log.push('useLayoutEffect unmount');
});
return text;
}
await act(() => {
ReactNoop.renderLegacySyncRoot(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual(['useLayoutEffect mount', 'useEffect mount']);
});
it('should not double invoke class lifecycles in legacy mode', async () => {
const log = [];
class App extends React.PureComponent {
componentDidMount() {
log.push('componentDidMount');
}
componentDidUpdate() {
log.push('componentDidUpdate');
}
componentWillUnmount() {
log.push('componentWillUnmount');
}
render() {
return this.props.text;
}
}
await act(() => {
ReactNoop.renderLegacySyncRoot(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual(['componentDidMount']);
});
if (__DEV__) {
it('should flush double-invoked effects within the same frame as layout effects if there are no passive effects', async () => {
const log = [];
function ComponentWithEffects({label}) {
React.useLayoutEffect(() => {
Scheduler.log(`useLayoutEffect mount "${label}"`);
log.push(`useLayoutEffect mount "${label}"`);
return () => {
Scheduler.log(`useLayoutEffect unmount "${label}"`);
log.push(`useLayoutEffect unmount "${label}"`);
};
});
return label;
}
await act(async () => {
ReactNoop.render(
<React.StrictMode>
<ComponentWithEffects label={'one'} />
</React.StrictMode>,
);
await waitForPaint(['useLayoutEffect mount "one"']);
expect(log).toEqual([
'useLayoutEffect mount "one"',
'useLayoutEffect unmount "one"',
'useLayoutEffect mount "one"',
]);
});
log.length = 0;
await act(async () => {
ReactNoop.render(
<React.StrictMode>
<ComponentWithEffects label={'one'} />
<ComponentWithEffects label={'two'} />
</React.StrictMode>,
);
expect(log).toEqual([]);
await waitForPaint([
'useLayoutEffect unmount "one"',
'useLayoutEffect mount "one"',
'useLayoutEffect mount "two"',
]);
expect(log).toEqual([
'useLayoutEffect unmount "one"',
'useLayoutEffect mount "one"',
'useLayoutEffect mount "two"',
'useLayoutEffect unmount "two"',
'useLayoutEffect mount "two"',
]);
});
});
it('should double invoke effects only for newly mounted components', async () => {
const log = [];
function ComponentWithEffects({label}) {
React.useEffect(() => {
log.push(`useEffect mount "${label}"`);
Scheduler.log(`useEffect mount "${label}"`);
return () => {
log.push(`useEffect unmount "${label}"`);
Scheduler.log(`useEffect unmount "${label}"`);
};
});
React.useLayoutEffect(() => {
log.push(`useLayoutEffect mount "${label}"`);
Scheduler.log(`useLayoutEffect mount "${label}"`);
return () => {
log.push(`useLayoutEffect unmount "${label}"`);
Scheduler.log(`useLayoutEffect unmount "${label}"`);
};
});
return label;
}
await act(async () => {
ReactNoop.render(
<React.StrictMode>
<ComponentWithEffects label={'one'} />
</React.StrictMode>,
);
await waitForAll([
'useLayoutEffect mount "one"',
'useEffect mount "one"',
]);
expect(log).toEqual([
'useLayoutEffect mount "one"',
'useEffect mount "one"',
'useLayoutEffect unmount "one"',
'useEffect unmount "one"',
'useLayoutEffect mount "one"',
'useEffect mount "one"',
]);
});
log.length = 0;
await act(async () => {
ReactNoop.render(
<React.StrictMode>
<ComponentWithEffects label={'one'} />
<ComponentWithEffects label={'two'} />
</React.StrictMode>,
);
await waitFor([
'useLayoutEffect unmount "one"',
'useLayoutEffect mount "one"',
'useLayoutEffect mount "two"',
]);
expect(log).toEqual([
'useLayoutEffect unmount "one"',
'useLayoutEffect mount "one"',
'useLayoutEffect mount "two"',
]);
log.length = 0;
await waitForAll([
'useEffect unmount "one"',
'useEffect mount "one"',
'useEffect mount "two"',
]);
expect(log).toEqual([
'useEffect unmount "one"',
'useEffect mount "one"',
'useEffect mount "two"',
'useLayoutEffect unmount "two"',
'useEffect unmount "two"',
'useLayoutEffect mount "two"',
'useEffect mount "two"',
]);
});
});
it('double invoking for effects for modern roots', async () => {
const log = [];
function App({text}) {
React.useEffect(() => {
log.push('useEffect mount');
return () => log.push('useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect mount');
return () => log.push('useLayoutEffect unmount');
});
return text;
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect mount',
'useEffect mount',
'useLayoutEffect unmount',
'useEffect unmount',
'useLayoutEffect mount',
'useEffect mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'update'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect unmount',
'useLayoutEffect mount',
'useEffect unmount',
'useEffect mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual(['useLayoutEffect unmount', 'useEffect unmount']);
});
it('multiple effects are double invoked in the right order (all mounted, all unmounted, all remounted)', async () => {
const log = [];
function App({text}) {
React.useEffect(() => {
log.push('useEffect One mount');
return () => log.push('useEffect One unmount');
});
React.useEffect(() => {
log.push('useEffect Two mount');
return () => log.push('useEffect Two unmount');
});
return text;
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useEffect One mount',
'useEffect Two mount',
'useEffect One unmount',
'useEffect Two unmount',
'useEffect One mount',
'useEffect Two mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'update'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useEffect One unmount',
'useEffect Two unmount',
'useEffect One mount',
'useEffect Two mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual(['useEffect One unmount', 'useEffect Two unmount']);
});
it('multiple layout effects are double invoked in the right order (all mounted, all unmounted, all remounted)', async () => {
const log = [];
function App({text}) {
React.useLayoutEffect(() => {
log.push('useLayoutEffect One mount');
return () => log.push('useLayoutEffect One unmount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect Two mount');
return () => log.push('useLayoutEffect Two unmount');
});
return text;
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect One mount',
'useLayoutEffect Two mount',
'useLayoutEffect One unmount',
'useLayoutEffect Two unmount',
'useLayoutEffect One mount',
'useLayoutEffect Two mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'update'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect One unmount',
'useLayoutEffect Two unmount',
'useLayoutEffect One mount',
'useLayoutEffect Two mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual([
'useLayoutEffect One unmount',
'useLayoutEffect Two unmount',
]);
});
it('useEffect and useLayoutEffect is called twice when there is no unmount', async () => {
const log = [];
function App({text}) {
React.useEffect(() => {
log.push('useEffect mount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect mount');
});
return text;
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect mount',
'useEffect mount',
'useLayoutEffect mount',
'useEffect mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'update'} />
</React.StrictMode>,
);
});
expect(log).toEqual(['useLayoutEffect mount', 'useEffect mount']);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual([]);
});
it('disconnects refs during double invoking', async () => {
const onRefMock = jest.fn();
function App({text}) {
return (
<span
ref={ref => {
onRefMock(ref);
}}>
text
</span>
);
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(onRefMock.mock.calls.length).toBe(3);
expect(onRefMock.mock.calls[0][0]).not.toBeNull();
expect(onRefMock.mock.calls[1][0]).toBe(null);
expect(onRefMock.mock.calls[2][0]).not.toBeNull();
});
it('passes the right context to class component lifecycles', async () => {
const log = [];
class App extends React.PureComponent {
test() {}
componentDidMount() {
this.test();
log.push('componentDidMount');
}
componentDidUpdate() {
this.test();
log.push('componentDidUpdate');
}
componentWillUnmount() {
this.test();
log.push('componentWillUnmount');
}
render() {
return null;
}
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App />
</React.StrictMode>,
);
});
expect(log).toEqual([
'componentDidMount',
'componentWillUnmount',
'componentDidMount',
]);
});
it('double invoking works for class components', async () => {
const log = [];
class App extends React.PureComponent {
componentDidMount() {
log.push('componentDidMount');
}
componentDidUpdate() {
log.push('componentDidUpdate');
}
componentWillUnmount() {
log.push('componentWillUnmount');
}
render() {
return this.props.text;
}
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'componentDidMount',
'componentWillUnmount',
'componentDidMount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'update'} />
</React.StrictMode>,
);
});
expect(log).toEqual(['componentDidUpdate']);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual(['componentWillUnmount']);
});
it('double flushing passive effects only results in one double invoke', async () => {
const log = [];
function App({text}) {
const [state, setState] = React.useState(0);
React.useEffect(() => {
if (state !== 1) {
setState(1);
}
log.push('useEffect mount');
return () => log.push('useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect mount');
return () => log.push('useLayoutEffect unmount');
});
log.push(text);
return text;
}
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'mount',
'mount',
'useLayoutEffect mount',
'useEffect mount',
'useLayoutEffect unmount',
'useEffect unmount',
'useLayoutEffect mount',
'useEffect mount',
'mount',
'mount',
'useLayoutEffect unmount',
'useLayoutEffect mount',
'useEffect unmount',
'useEffect mount',
]);
});
it('newly mounted components after initial mount get double invoked', async () => {
let _setShowChild;
const log = [];
function Child() {
React.useEffect(() => {
log.push('Child useEffect mount');
return () => log.push('Child useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('Child useLayoutEffect mount');
return () => log.push('Child useLayoutEffect unmount');
});
return null;
}
function App() {
const [showChild, setShowChild] = React.useState(false);
_setShowChild = setShowChild;
React.useEffect(() => {
log.push('App useEffect mount');
return () => log.push('App useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('App useLayoutEffect mount');
return () => log.push('App useLayoutEffect unmount');
});
return showChild && <Child />;
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App />
</React.StrictMode>,
);
});
expect(log).toEqual([
'App useLayoutEffect mount',
'App useEffect mount',
'App useLayoutEffect unmount',
'App useEffect unmount',
'App useLayoutEffect mount',
'App useEffect mount',
]);
log.length = 0;
await act(() => {
_setShowChild(true);
});
expect(log).toEqual([
'App useLayoutEffect unmount',
'Child useLayoutEffect mount',
'App useLayoutEffect mount',
'App useEffect unmount',
'Child useEffect mount',
'App useEffect mount',
'Child useLayoutEffect unmount',
'Child useEffect unmount',
'Child useLayoutEffect mount',
'Child useEffect mount',
]);
});
it('classes and functions are double invoked together correctly', async () => {
const log = [];
class ClassChild extends React.PureComponent {
componentDidMount() {
log.push('componentDidMount');
}
componentWillUnmount() {
log.push('componentWillUnmount');
}
render() {
return this.props.text;
}
}
function FunctionChild({text}) {
React.useEffect(() => {
log.push('useEffect mount');
return () => log.push('useEffect unmount');
});
React.useLayoutEffect(() => {
log.push('useLayoutEffect mount');
return () => log.push('useLayoutEffect unmount');
});
return text;
}
function App({text}) {
return (
<React.StrictMode>
<ClassChild text={text} />
<FunctionChild text={text} />
</React.StrictMode>
);
}
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'componentDidMount',
'useLayoutEffect mount',
'useEffect mount',
'componentWillUnmount',
'useLayoutEffect unmount',
'useEffect unmount',
'componentDidMount',
'useLayoutEffect mount',
'useEffect mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(
<React.StrictMode>
<App text={'mount'} />
</React.StrictMode>,
);
});
expect(log).toEqual([
'useLayoutEffect unmount',
'useLayoutEffect mount',
'useEffect unmount',
'useEffect mount',
]);
log.length = 0;
await act(() => {
ReactNoop.render(null);
});
expect(log).toEqual([
'componentWillUnmount',
'useLayoutEffect unmount',
'useEffect unmount',
]);
});
}
});