When writing unit tests with ava and vuejs how can I trigger the Enter keyup event?
For example, with the following component how can I test that someFunction has been called?
<input
#keyup.enter="someFunction"
/>
I've found on vue-test-utils docs. I need to call input.trigger('keyup.enter');
Here is a full example:
test('it should call add mutation', t => {
const wrapper = mount(Todo, { localVue, store: createStore() });
const input = wrapper.find('.todo-value');
input.setValue('New todo item');
input.trigger('keyup.enter');
t.true(mutations.add.called);
});
Related
I am trying to learn how to test events emitted through a global Event Bus. Here's the code with some comments in the places I don't know what to do.
// EvtBus.js
import Vue from 'vue';
export const EvtBus = new Vue();
<!-- CouponCode.vue -->
<template>
<div>
<input
class="coupon-code"
type="text"
v-model="code"
#input="validate">
<p v-if="valid">
Coupon Redeemed: {{ message }}
</p>
</div>
</template>
<script>
import { EvtBus } from '../EvtBus.js';
export default {
data () {
return {
code: '',
valid: false,
coupons: [
{
code: '50OFF',
discount: 50,
message: '50% Off!'
},
{
code: 'FREE',
discount: 100,
message: 'Entirely Free!'
}
]
};
},
created () {
EvtBus.$on('coupon-applied', () => {
//console.info('had a coupon applied event on component');
});
},
methods: {
validate () {
// Extract the coupon codes into an array and check if that array
// includes the typed in coupon code.
this.valid = this.coupons.map(coupon => coupon.code).includes(this.code);
if (this.valid) {
this.$emit('applied');
// I NEVER see this on the coupon-code.spec.js
EvtBus.$emit('coupon-applied');
}
}
},
computed: {
message () {
return this.coupons.find(coupon => coupon.code === this.code).message;
}
}
}
</script>
// tests/coupon-code.spec.js
import expect from 'expect';
import { mount } from '#vue/test-utils';
import CouponCode from '../src/components/CouponCode.vue';
import { EvtBus } from '../src/EvtBus.js';
describe('Reminders', () => {
let wrp;
beforeEach(() => {
wrp = mount(CouponCode);
});
it('broadcasts the percentage discount when a valid coupon code is applied', () => {
let code = wrp.find('input.coupon-code');
code.element.value = '50OFF';
code.trigger('input');
console.log(wrp.emitted('applied'));
//
// I NEVER see this on the outpout.
// How can I test it through a global event bus rather than
// an event emitted from the component instance?
//
EvtBus.$on('coupon-applied', () => {
console.log('coupon was applied through event bus');
});
// Passes, but not using EvtBus instance.
expect(wrp.emitted('applied')).toBeTruthy;
});
});
So, my doubt is how to test that the global event bus is emitting and listening to events inside components that use that event bus.
So, is it possible to test the global Event Bus using Vue Test Utils or I should use another approach?
If component is using global EventBus, eg that's imported outside of given component and assigned to window.EventBus, then it's possible to use global Vue instance to redirect $on or $emit events to wrapper's vm instance. That way you can proceed writing tests as if component is emitting via this.$emit instead of EventBus.$emit:
it('clicking "Settings" button emits "openSettings"', () => {
global.EventBus = new Vue();
global.EventBus.$on('openSettings', (data) => {
wrapper.vm.$emit('openSettings', data);
});
// component emits `EventBus.$emit('openSettings')`
expect(wrapper.emitted('openSettings')).toBeTruthy(); // pass
});
Well,
EvtBus.$on('coupon-applied', () => {
console.log('coupon was applied through event bus');
});
This code in your spec file won't be called because the mounted wrp component is not using the same EvtBus you are importing in your spec file above.
What you require to test this is an npm package named inject-loader so that you can provide your own implementation(stub) of the EvtBus dependency of your coupon code component.
Somewhat like this
const couponCodeInjector = require('!!vue-loader?inject!src/views/CouponCode');
const stubbedModules = {
'../EvtBus.js': {
$on : sandbox.spy((evtName, cb) => cb());
}
};
const couponCode = couponCodeInjector(stubbedModules);
and then in your unit test you can assert whether the stubbedModules['../EvtBus.js'].$on has been called or not when code.trigger('input');
PS: I haven't used vue-test-utils. So I don't know exactly how to the stubbing with this npm package.
But the main thing you need to do is to find a way to stub your EvtBus dependency in the CouponCode component in such a way that you can apply a spy on it and check whether that spy has been called or not.
Unit tests should focus on testing a single component in isolation. In this case, you want to test if the event is emitted, since that is the job of CouponCode.vue. Remember, unit tests should focus on testing the smallest units of code, and only test one thing at a time. In this case, we care that the event is emitted -- EventBus.test.js is where we test what happens when the event is emitted.
Noe that toBeTruthy is a function - you need (). expect(wrp.emitted('applied')).toBeTruthy is actually not passing, since you need () - at the moment, it is actually doing nothing -- no assertion is made.
What your assertion should look like is:
expect(wrp.emitted('applied')).toBeTruthy()
You can go one step further, and ensure it was only emitted once by doing something like expect(wrp.emitted().applied.length).toBe(1).
You then test InputBus in isolation, too. If you can post the code for that component, we can work through how to test it.
I worked on a big Vue app recently and contributed a lot to the main repo and documentation, so I'm happy to help out wherever I can.
Let me know if that helps or you need more guidance. If possible, post EventBus.vue as well.
I got the same issue with vue-test-utils and Jest. For me, createLocalVue() of vue-test-utils library fixed the issue. This function creates a local copy of Vue to use when mounting the component. Installing plugins on this copy of Vue prevents polluting the original Vue copy. (https://vue-test-utils.vuejs.org/api/options.html#localvue)
Adding this to your test file will fix the issue:
const EventBus = new Vue();
const GlobalPlugins = {
install(v) {
// Event bus
v.prototype.$bus = EventBus;
},
};
// create a local instance of the global bus
const localVue = createLocalVue();
localVue.use(GlobalPlugins);
jest.mock('#/main', () => ({
$emit: jest.fn(),
}));
Include this in code in your spec file at the very begining.
Note: '#/main' is the file from which you are importing Event Bus.
Currently, In my react app, I have an ajax call method that has setState if the ajax call is successful, I already mocked the api response, it seems that the method won't execute anything else other than returning the response
For example,
// This is the ajax method
getProductData(productId) {
// I already successfully mocked the response
getProductById(productId).then(productResponse => {
// I am trying make sure that the state is being updated with response data
this.setState({
product: productResponse.data
})
});
}
This is my test
test('Make sure my state is being updated with response data', async () => {
const component = shallow(
<MyComponent />
);
component.instance().getProductData(1);
// This is where my test failed, as it's not updating anything
expect(component.state().product).to.equal('SOMETHING');
});
Tried using setTimeout to asynchronously test the method, suggested by Jonah Pereira
test('Make sure my state is being updated with response data', async () => {
const component = shallow(
<MyComponent />
);
component.instance().getProductData(1);
// Using settimeout still not solving the problem,
setTimeout(() => {
expect(component.state().product).to.equal('SOMETHING');
// Not even this, that means the test totally ignored the setTimeout
expect('abc').to.equal('cba');
}, 0)
});
Usually if I test my react components which involve AJAX calls i enclose my methods inside a setTimeout
setTimeout(() =>
{
expect(component.state().product).to.equal('SOMETHING');
}, 0);
I have this React functional UI only component, which has two props passed in, the second being a function that is passed from its parent component. The onClick calls 'delegates' to a function in the parent container component, this parent method is then responsible for dispatching to a redux store.
import React, {Component} from 'react';
import PropTypes from 'prop-types';
const BotShowUI = ({ bot, onClick }) => {
return(
<div id={bot.id} onClick={onClick}>
{bot.id} : {bot.text}
</div>
)
}
BotShowUI.propTypes = {
bot: PropTypes.object.isRequired,
onClick: PropTypes.func.isRequired
};
export default BotShowUI;
My test spec is, which uses Jasmine
import React, {Component} from 'react';
import { mount } from 'enzyme';
import BotShowUI from '../botShowUI';
function onClickFunction(){};
describe('botShowUI', () => {
const bot = {id: 1, isDone: false, text: 'bot 123'};
const expectedDivText = '1 : bot 123';
const wrapper = mount(<BotShowUI bot={bot} onClick={onClickFunction} />);
it(' div has been rendered ', () => {
expect(wrapper.find('div').first()).not.toBe(null);
});
it(' div displays the correct bot text ', () => {
expect(wrapper.find('div').first().text()).toEqual(expectedDivText)
});
it(' div click event fired ', () => {
wrapper.simulate('click');
expect(wrapper.state('onClick')).toBe(true);
});
});
This last assertion fails with
Chrome 57.0.2987 (Windows 10 0.0.0) botShowUI div click event fired FAILED
TypeError: Cannot read property 'onClick' of null
at ReactWrapper.state (webpack:///~/enzyme/build/ReactWrapper.js:825:24 <- tests.webpack.js:26303:25)
at Object.<anonymous> (webpack:///app/react/components/bots/_tests/botShowUI.spec.js:25:23 <- tests.webpack.js:25415:25)
wrapper.simulate('click'); works, but the next line fails
What is the correct way to assert that the click was fired ?
Do I have to drop into wrapper's props/children instead of using state ?
I'm not trying to test the parent container in any way, the two are isolated.
This test is only concerned with this UI component.
First thing is that onClick isn't on state, but on props, so you will have to access it by doing wrapper.props('onClick').
Secondly, to test whether onClick has been handled or not is to use a spy, rather than an empty function. If you do not want to use spy, you can still do that, but not the way you have done. If you are interested, I can post some pseudo-code for that too. But coming back to using spies, you can use a spy as the onClick prop. Below is the code for that. I have hand-written it, so please check for any syntax error, but you should get the idea on what needs to be done.
it('should call the onClick handler on click', () => {
const onClickFunction = sinon.spy()
wrapper = mount(<BotShowUI bot={bot} onClick={onClickFunction} />)
wrapper.simulate('click');
expect(onClickFunction).toHaveBeenCalled();
})
Based on Abhishek's answer here's my solution for Jasmine
it(' div click event fired ', () => {
let onClickFunction_spy = jasmine.createSpy('onClickFunction');
const wrapper = mount(<BotShowUI bot={bot} onClick={onClickFunction_spy} />);
wrapper.simulate('click');
expect(onClickFunction_spy).toHaveBeenCalled();
});
Hope this helps anyone.
I have a component in my application.It have a form with text fields.It will have a submit button.When submit is pressed it will send a post request to the server.I also handled a keyboard event in components js file.When enter is pressed it will send a post request to the server.When the enter key is pressed two times continuously it is making two post request to the server with first request success and second request failed.
I want to make my app in such away even if the user presses the enter key two times continuously it should send only one post request to the server.Can any one help me solve this issue.Thanks in advance.
components js file:
export default Component.extend({
keyDown:function(event){
let self = this;
if(event.keyCode === 13){
self.send('submitform');
return false;
}
actions: {
submitform(){
//logic to handle the post request to the server
}
}
Try usig Ember.run.debounce,
export default Ember.Component.extend({
keyDown: function(event) {
let self = this;
if (event.keyCode === 13) {
// self.send('submitform');
Ember.run.debounce(self,self.get('submitform'),400);
return false;
}
},
submitform(){
//handle submit form logic
}
});
You can play with twiddle here
You will want to disable submitForm() until your POST request is complete. You can do this by setting a property submitting on the component and turning it on before the POST and off once the promise is resolved. Perhaps try something like:
export default Ember.Component.extend({
submitting: false,
keyDown: function(event) {
if (event.keyCode === 13) {
this.submitform();
}
},
submitform() {
// Run only if not currently submitting
if (!this.get('submitting')) {
// What to do when submit succeeds
const success = () => {
this.set('submitting', false);
}
// What to do when submit fails
const fail = () => {
this.set('submitting', false);
}
// Do the POST request
this.set('submitting', true);
this.get('someModel').save().then(success).catch(fail);
};
}
});
And, unrelated, this allows you to do fun things with your template such as disabling and styling the submit button for as long as the POST promise is not resolved yet:
<button {{action 'submitForm'}} disabled={{submitting}} class="{{if submitting 'loading'}}">
{{#if submitting}}
Submitting ...
{{else}}
Submit
{{/if}}
</button>
Oh and lastly, no need to use let self = this; anymore. Use ES6 arrow functions () => { ... } instead so you can keep using this inside.
I want to unit test a directive that emulates a placeholder, where the input value is cleared only on keyup/down events.
You need to create an event programatically and trigger it. To do so including jQuery for unit tests is quite useful. For example, you could write a simple utility like this:
var triggerKeyDown = function (element, keyCode) {
var e = $.Event("keydown");
e.which = keyCode;
element.trigger(e);
};
and then use it in your unit test like so:
triggerKeyDown(element, 13);
You can see this technique in action in the http://angular-ui.github.io/bootstrap/ project here: https://github.com/angular-ui/bootstrap/blob/master/src/typeahead/test/typeahead.spec.js
Disclaimer: let's be precise here: I'm not advocating using jQuery with AngularJS! I'm just saying that it is a useful DOM manipulation utility for writing tests interacting with the DOM.
To make the above code work without jQuery, change:
$.Event('keydown')
to:
angular.element.Event('keydown')
I had issues with using accepted answer. I found other soultion.
var e = new window.KeyboardEvent('keydown', {
bubbles: true,
cancelable: true,
shiftKey: true
});
delete e.keyCode;
Object.defineProperty(e, 'keyCode', {'value': 27});
$document[0].dispatchEvent(e);
Working example can be found here
I got something like this working.
element.triggerHandler({type:"keydown", which:keyCode});
if you are using angular2, you can trigger any event by calling dispatchEvent(new Event('mousedown')) on HTMLElement instance. for example: Tested with angular 2.rc1
it('should ...', async(inject([TestComponentBuilder], (tcb:TestComponentBuilder) => {
return tcb.createAsync(TestComponent).then((fixture: ComponentFixture<any>) => {
fixture.detectChanges();
let com = fixture.componentInstance;
/* query your component to select element*/
let div:HTMLElement = fixture.nativeElement.querySelector('div');
/* If you want to test #output you can subscribe to its event*/
com.resizeTest.subscribe((x:any)=>{
expect(x).toBe('someValue');
});
/* If you want to test some component internal you can register an event listener*/
div.addEventListener('click',(x)=>{
expect(x).toBe('someOtherValue');
});
/* if you want to trigger an event on selected HTMLElement*/
div.dispatchEvent(new Event('mousedown'));
/* For click events you can use this short form*/
div.click();
fixture.detectChanges();
});
I recently wanted to test this HostListener on a component (Angular 2):
#HostListener('keydown.esc') onEsc() {
this.componentCloseFn();
};
And after searching for some time, this is working:
..
nativeElement.dispatchEvent(new KeyboardEvent('keydown', {'key': 'Escape'}));
...