Test case for child components onClick function - testing

I want to test the onClick functionality of MenuPopover.Item id={3} if it was called once or not after clicking on it.
import React from 'react';
import copy from 'copy-to-clipboard';
const TableMenu = ({show, target, onClick, onHide, addedType, disable, readonly, rowId, supportRestore, supportDelete, isRestored}) => (
<MenuPopover
onClick={onClick}
onHide={onHide}>
{!readonly && (addedType ?
<MenuPopover.Item id={1} label='Delete' disabled=true/> :
<MenuPopover.Item id={2} label='Restore' disabled=false/>
)}
<MenuPopover.Item id={3} onClick={() => copy(rowId)} label='Copy'/>
</MenuPopover>
);
Test case written so far
const onCopySpy = sinon.spy();
const props = {
///
onCopy: onCopySpy,
///
};
it('check method onCopy called', () => {
const wrapper = shallow(<TableMenu {...props}/>);
expect(wrapper.find('MenuPopover').children()).to.have.lengthOf(2);
wrapper.find(MenuPopover.Item).... //Test case to call the onClick function
expect(onCopySpy.calledOnce).to.eql(true);
});

copy needs to be mocked in tests:
import copy from 'copy-to-clipboard';
jest.mock('copy-to-clipboard', () => sinon.spy());
...
const wrapper = shallow(<TableMenu {...props}/>);
wrapper.find(MenuPopover.Item).props().onClick();
expect(copy.calledOnce).to.eql(true);
This can be alternatively done with simulate but it does the same thing internally.

Related

Export child components and use individually

I have a case where I need to export two child components and use individually.
Much Desired outcome (Extremely simplified):
Controls.js:
const Controller = ( props ) => {
const ControlBoxes = () => {
return(<Button>Move around!</Button>)
}
const MoveableBox = () => {
return(<View>I will be moved! </View>)
}
return {ControlBoxes, MoveableBox}
}
export default Builder
Canvas.js:
import Controller from './controls'
const boxScaleMove = boxes.map((box, index) => {
return (
<Bulilder.MoveableBox key={box.id} box={box}/>
)
}
const boxController = boxes.map((box, index) => {
return (
<Bulilder.ControlBoxes key={box.id} box={box}/>
)
}
return (
...
{boxController}
...
...
{boxScaleMove}
...
)
Any idea how I can achieve this or am I missing something fundamental? The main issue is that I want to avoid resorting to useContext (due to performance reasons in the case of a lot of boxes rendered) and be able to share variables and states between MoveableBox-component and ControlBoxes-component via Controller -parent.
Any help would be greatly appreciated.
You could use the compound component and use a lower level context to avoid re-rendering of the whole tree and share states across your components that way, below I would ilustrate a basic example of how that would work.
const RandomContext = createContext();
export default function Controller({children, ...rest}) {
const [randomState, setRandom] = useState(0);
return (
<RandomContext.Provider value={{ randomState, setRandom }}>
<div {...rest}>{children}</div>
</RandomContext.Provider>
);
}
Controller.ControlBoxes = function (props) {
const { setRnadom } = useContext(RandomContext);
return (
<Button onClick={() => setRandom(2)} {...props}>Move around!</Button>
);
};
Controller.MoveableBox = function (props) {
const { randomState } = useContext(RandomContext);
return randomState ? <View {...props}>I will be moved!</View> : null;
};
And you would use it as:
<Controller>
<Controller.ControlBoxes />
<Controller.MoveableBox />
<Controller>
In the compound components pattern we are leveraging the fact that in javascript when you declare a function you create a function/object combo. Therefor Controller function is both a function and an object, so we can assign properties the the object part of that combo, properties which are in our case ControlBoxes and MoveableBox which are functions themselves.
NOTE you should probably assign named function the the properties of that object, it's easier to debug if the case needed.
Example.Function = function ExampleFunction(props) {
return "Example";
};

Check if first child renders nothing in Native Testing Library

Suppose I have the following component:
const MyComponent = () => null;
In React Testing Library (RTL), the following, AFAIK, should work:
const { container } = render(<MyComponent />);
expect(container.firstChild).toBeEmpty();
where .toBeEmpty is a custom matcher from jest-dom. However, in NTL, container.firstChild is not defined so I can't use .toBeEmpty matcher from jest-native. After some experimentation, I got it to work as follows:
expect(container.children[0]).toBeUndefined();
Is there any other, possibly better, way to do this?
In my case I had a situation like so:
function PhotoComponent({policy}) {
if (policy === 'unavailable')
return null;
return (<View />);
}
Tested like this:
it("should not render if policy is 'unavailable'", () => {
const {toJSON} = render(<PhotoComponent policy={'unavailable'} />);
const children = toJSON().children;
expect(children.length).toBe(0);
});
Some times you will want to filter the children like, for instance:
const children = toJSON().children.filter(
(child) => child.type === 'View' || child.type === 'Modal'
);
Keep calm and Happy coding!

React navigation prevent double push()

I'm building an app with react-navigation-4.2.1. The app has multiple stack navigators. So there are a lots of navigation.push('Routename') calls.
Trouble is when the control surface (i.e. TouchableOpacity) is tapped rapidly multiple times (first one, and the rest during screen transition) I end up pushing multiple screens into the stack. Is there a way to restrict the surface to the first tap/call of push()?
The component below is what i use to make things touchable. it handle multiple touches in small period of time.
Use component below instead of TouchableOpacity. wrap any thing you want with this component and it will be touchable.
<SafeTouch
onPress={...}
>
<Text> hey! im a touchable text now</Text>
</SafeTouch>
The component below is written used TypeScirpt.
every touch within 300ms after first touch will be ignored(thats where help you with your problem).
import * as React from 'react'
import { TouchableOpacity } from 'react-native'
interface ISafeTouchProps {
onPress: () => void
onLongPress?: () => void
onPressIn?: () => void
onPressOut?: () => void,
activeOpacity?: number,
disabled?: boolean,
style: any
}
export class SafeTouch extends React.PureComponent<ISafeTouchProps> {
public static defaultProps: ISafeTouchProps = {
onPress: () => { },
onLongPress: () => { },
onPressIn: () => { },
onPressOut: () => { },
disabled: false,
style: null
}
private isTouchValid: boolean = true
private touchTimeout: any = null
public constructor(props: ISafeTouchProps) {
super(props)
{// Binding methods
this.onPressEvent = this.onPressEvent.bind(this)
}
}
public render(): JSX.Element {
return (
<TouchableOpacity
onPress={this.onPressEvent}
onLongPress={this.props.onLongPress}
onPressIn={this.props.onPressIn}
onPressOut={this.props.onPressOut}
activeOpacity={this.props.activeOpacity}
disabled={this.props.disabled}
style={[{minWidth: 24, minHeight: 24}, this.props.style]}
>
{
this.props.children
}
</TouchableOpacity>
)
}
public componentWillUnmount() {
this.clearTimeoutIfExists()
}
private onPressEvent(): void {
requestAnimationFrame(() => {
if (this.isTouchValid === false) {
return
}
this.isTouchValid = false
this.clearTimeoutIfExists()
this.touchTimeout = setTimeout(() => {
this.isTouchValid = true
}, 300)
if (typeof this.props.onPress === 'function') {
this.props.onPress()
}
})
}
private clearTimeoutIfExists(): void {
if (this.touchTimeout != null) {
clearTimeout(this.touchTimeout)
this.touchTimeout = null
}
}
}
This is the proper behavior for Push and it is not a bug if you want
to avoid the duplicate screen on double tab you can just use navigation.navigate.
To avoid pushing the screen more than once when clicking in the same button in a short span of time, I created a generic hook to avoid running a function more than once (accepting an interval to allow run again):
export const useCallOnce = <T extends unknown[], K>(
fn: (...args: T) => K,
allowAfter?: number,
) => {
const ref = React.useRef<number | undefined>();
const resultFn = (...args: T) => {
const now = new Date().getTime();
if (!ref.current || (allowAfter && ref.current + allowAfter < now)) {
ref.current = now;
return fn(...args);
}
};
return resultFn;
};
Then, you can just call it as in the following example:
const navigation = useNavigation<NativeStackNavigationProp<{ ExampleScreen: undefined }>>();
const push = useCallOnce(() => navigation.push('ExampleScreen'), 500);
// just call on the button click event as: onSomeEvent={() => push()}
You can create a generic button component that accept the push parameters with the hook above, similar to the example, and use this button whenever you want a button to navigate between pages.

How to toggle a boolean value using Context and Hooks?

I am using ReactContext and Hooks to show and hide a Modal on click of a button.
Following is my Context code
const setPrivacyPolicyModalVisibility = dispatch => {
return ({visible}) => {
visible
? dispatch({type: 'enablePrivacyPolicyModalVisibility'})
: dispatch({type: 'disablePrivacyPolicyModalVisibility'});
};
};
And the reducer code for the same is something as follows
case 'enablePrivacyPolicyModalVisibility':
return {...state, ...{enablePrivacyPolicy: true}};
case 'disablePrivacyPolicyModalVisibility':
return {...state, ...{enablePrivacyPolicy: false}};
Some setup code in my class
const {state, setPrivacyPolicyModalVisibility} = useContext(Context);
const [privacyVisibility, setPrivacyVisibility] = useState(false);
on click of button I am calling the following code
<TouchableOpacity
onPress={() => {
setPrivacyVisibility(true);
console.log(`${privacyVisibility}`);
setPrivacyPolicyModalVisibility({privacyVisibility});
}}.....
As you can see I am console logging the privacyVisibility value but it is always false which I fail to understand
Following is my code in the component to hide or show the Modal
{state.enablePrivacyPolicy ? (
<SettingsPrivacyModal visible={true} />
) : (
<SettingsPrivacyModal visible={false} />
)}
The Modal code is proper as I have tried setting default value to true just to check if modal is visible then it works, but on click of button press the state value does not change and I am not able to see the modal as the value is always false
The issue seems to be in the onPress callback:
onPress={() => {
const privacyVisibility_new = !privacyVisibility;
console.log( privacyVisibility_new );
setPrivacyVisibility( privacyVisibility_new );
setPrivacyPolicyModalVisibility( privacyVisibility:privacyVisibility_new );
}}
When the cycle reaches the callback privacyVisibility has the default which is false. I think you are assuming that once setPrivacyVisibility is called, the privacyVisibility variable will have the new value in that same cycle; but it won't have the updated value until the component renders again.
setPrivacyPolicyModalVisibility doesn't seem to be correct. I am not sure where is dispatch exactly, but assuming it is at the same level as the function you can simply use it inside.
const setPrivacyPolicyModalVisibility = visible => {
if ( visible ) {
dispatch({ type: "enablePrivacyPolicyModalVisibility" });
} else {
dispatch({ type: "disablePrivacyPolicyModalVisibility" });
}
};
You might want to simplify your reducer and send directly the visible value:
const setPrivacyPolicyModalVisibility = visible =>
dispatch({ type: "setPrivacyPolicyModalVisibility", payload: visible });
.
case 'setPrivacyPolicyModalVisibility':
return { ...state, is_privacyPolicy_visible: action.payload };
Actually the error was simple. I am using the visible parameter as props in setPrivacyPolicyModalVisibility but while setting I am passing prop of different name
Thanks to #Alvaro for pointing me in the right direction

Crash with simple history push

just trying come silly stuff and playing around with Cycle.js. and running into problem. Basically I just have a button. When you click it it's suppose to navigate the location to a random hash and display it. Almost like a stupid router w/o predefined routes. Ie. routes are dynamic. Again this isn't anything practical I am just messing with some stuff and trying to learn Cycle.js. But the code below crashes after I click "Add" button. However the location is updated. If I actually just navigate to "#/asdf" it displays the correct content with "Hash: #/asdf". Not sure why the flow is crashing with error:
render-dom.js:242 TypeError: Cannot read property 'subscribe' of undefined(…)
import Rx from 'rx';
import Cycle from '#cycle/core';
import { div, p, button, makeDOMDriver } from '#cycle/dom';
import { createHashHistory } from 'history';
import ranomdstring from 'randomstring';
const history = createHashHistory({ queryKey: false });
function CreateButton({ DOM }) {
const create$ = DOM.select('.create-button').events('click')
.map(() => {
return ranomdstring.generate(10);
}).startWith(null);
const vtree$ = create$.map(rs => rs ?
history.push(`/${rs}`) :
button('.create-button .btn .btn-default', 'Add')
);
return { DOM: vtree$ };
}
function main(sources) {
const hash = location.hash;
const DOM = sources.DOM;
const vtree$ = hash ?
Rx.Observable.of(
div([
p(`Hash: ${hash}`)
])
) :
CreateButton({ DOM }).DOM;
return {
DOM: vtree$
};
}
Cycle.run(main, {
DOM: makeDOMDriver('#main-container')
});
Thank you for the help
I would further suggest using #cycle/history to do your route changing
(Only showing relevant parts)
import {makeHistoryDriver} from '#cycle/history'
import {createHashHistory} from 'history'
function main(sources) {
...
return {history: Rx.Observable.just('/some/route') } // a stream of urls
}
const history = createHashHistory({ queryKey: false })
Cycle.run(main, {
DOM: makeDOMDriver('#main-container'),
history: makeHistoryDriver(history),
})
On your function CreateButton you are mapping your clicks to history.push() instead of mapping it to a vtree which causes the error:
function CreateButton({ DOM }) {
...
const vtree$ = create$.map(rs => rs
? history.push(`/${rs}`) // <-- not a vtree
: button('.create-button .btn .btn-default', 'Add')
);
...
}
Instead you could use the do operator to perform the hashchange:
function CreateButton({ DOM }) {
const create$ =
...
.do(history.push(`/${rs}`)); // <-- here
const vtree$ = Observable.of(
button('.create-button .btn .btn-default', 'Add')
);
...
}
However in functional programming you should not perform side effects on you app logic, every function must remain pure. Instead, all side effects should be handled by drivers. To learn more take a look at the drivers section on Cycle's documentation
To see a working driver jump at the end of the message.
Moreover on your main function you were not using streams to render your vtree. It would have not been reactive to locationHash changes because vtree$ = hash ? ... : ... is only evaluated once on app bootstrapping (when the main function is evaluated and "wires" every streams together).
An improvement will be to declare your main's vtree$ as following while keeping the same logic:
const vtree$ = hash$.map((hash) => hash ? ... : ...)
Here is a complete solution with a small locationHash driver:
import Rx from 'rx';
import Cycle from '#cycle/core';
import { div, p, button, makeDOMDriver } from '#cycle/dom';
import { createHashHistory } from 'history';
import randomstring from 'randomstring';
function makeLocationHashDriver (params) {
const history = createHashHistory(params);
return (routeChange$) => {
routeChange$
.filter(hash => {
const currentHash = location.hash.replace(/^#?\//g, '')
return hash && hash !== currentHash
})
.subscribe(hash => history.push(`/${hash}`));
return Rx.Observable.fromEvent(window, 'hashchange')
.startWith({})
.map(_ => location.hash);
}
}
function CreateButton({ DOM }) {
const create$ = DOM.select('.create-button').events('click')
.map(() => randomstring.generate(10))
.startWith(null);
const vtree$ = Rx.Observable.of(
button('.create-button .btn .btn-default', 'Add')
);
return { DOM: vtree$, routeChange$: create$ };
}
function main({ DOM, hash }) {
const button = CreateButton({ DOM })
const vtree$ = hash.map(hash => hash
? Rx.Observable.of(
div([
p(`Hash: ${hash}`)
])
)
: button.DOM
)
return {
DOM: vtree$,
hash: button.routeChange$
};
}
Cycle.run(main, {
DOM: makeDOMDriver('#main-container'),
hash: makeLocationHashDriver({ queryKey: false })
});
PS: there is a typo in your randomstring function name, I fixed it in my example.