Angular2 test - not detecting changes - testing

I'm trying to check a dropdown is shown when a boolean is switched.
The boolean is an input on the component
#Component({
selector: 'dropdown',
directives: [NgClass],
template: `
<div [ngClass]="{open: open}">
</div>
`,
})
export class DropdownComponent {
#Input('open') open: boolean = false;
}
And the test
it('should open', injectAsync([TestComponentBuilder], (tcb: TestComponentBuilder) => {
return tcb.createAsync(DropdownComponent)
.then(fixture => {
let el = fixture.nativeElement;
let comp: DropdownComponent = fixture.componentInstance;
expect(el.className).toEqual('');
comp.open = true;
fixture.detectChanges();
expect(el.className).toEqual('open')
});
}));
I am guessing something different has to be done when the boolean is an #Input?

You are setting class open on the <div [ngClass]="{open: open}"> but checking on DropdownComponent. That's not the same.
Something like this should do what you want
var div = fixture.nativeElement.querySelector('div');
expect(div.className).toEqual('open');
or
var div = fixture.debugElement.query(By.css('div'));
expect(div.className).toEqual('open');
See also How do I trigger a ngModel model update in an Angular 2 unit test? for an example.

Related

Vue.js 3 Pinia store is only partially reactive. Why?

I'm using Pinia as Store for my Vue 3 application. The problem is that the store reacts on some changes, but ignores others.
The store looks like that:
state: () => {
return {
roles: [],
currentRole: 'Administrator',
elements: []
}
},
getters: {
getElementsForCurrentRole: (state) => {
let role = state.roles.find((role) => role.label == state.currentRole);
if (role) {
return role.permissions.elements;
}
}
},
In the template file, I communicate with the store like this:
<template>
<div>
<draggable
v-model="getElementsForCurrentRole"
group="elements"
#end="onDragEnd"
item-key="name">
<template #item="{element}">
<n-card :title="formatElementName(element.name)" size="small" header-style="{titleFontSizeSmall: 8px}" hoverable>
<n-switch v-model:value="element.active" size="small" />
</n-card>
</template>
</draggable>
</div>
</template>
<script setup>
import { NCard, NSwitch } from 'naive-ui';
import draggable from 'vuedraggable'
import { usePermissionsStore } from '#/stores/permissions';
import { storeToRefs } from 'pinia';
const props = defineProps({
selectedRole: {
type: String
}
})
const permissionsStore = usePermissionsStore();
const { getElementsForCurrentRole, roles } = storeToRefs(permissionsStore);
const onDragEnd = () => {
permissionsStore.save();
}
const formatElementName = (element) => {
let title = element.charAt(0).toUpperCase() + element.slice(1);
title = title.replace('-', ' ');
title = title.split(' ');
if (title[1]) {
title = title[0] + ' ' + title[1].charAt(0).toUpperCase() + title[1].slice(1);
}
if (typeof title == 'object') {
return title[0];
}
return title;
}
</script>
My problem is the v-model="getElementsForCurrentRole". When making changes, for example changing the value for the switch, the store is reactive and the changes are made successfully. But: If I try to change the Array order by dragging, the store does not update the order. I'm confused, because the store reacts on other value changes, but not on the order change.
What can be the issue here? Do I something wrong?
-Edit- I see the following warning on drag: Write operation failed: computed value is readonly
Workaround
As workaround I work with the drag event and write the new index directly to the store variable. But...its just a workaround. I would really appreciate a cleaner solution.
Here is the workaround code:
onDrag = (event) => {
if (event && event.type == 'end') {
// Is Drag Event. Save the new order manually directly in the store
let current = permissionsStore.roles.find((role) => role.value == permissionsStore.currentRole);
var element = current.permissions.elements[event.oldIndex];
current.permissions.elements.splice(event.oldIndex, 1);
current.permissions.elements.splice(event.newIndex, 0, element);
}
}
You should put reactive value on v-model.
getElementsForCurrentRole is from getters, so it is treated as computed value.
Similar to toRefs() but specifically designed for Pinia stores so
methods and non reactive properties are completely ignored.
https://pinia.vuejs.org/api/modules/pinia.html#storetorefs
I think this should work for you.
// template
v-model="elementsForCurrentRole"
// script
const { getElementsForCurrentRole, roles } = storeToRefs(permissionsStore);
const elementsForCurrentRole = ref(getElementsForCurrentRole.value);

VueJS directive similar to v-if fails unit tests (with vue-test-utils)

I'm trying to create a directive that has behaviour similar to v-if. Basically if the condition is true, the element should exist, if it's false, it shouldn't. I also need to ensure that those changes pass JEST tests. The purpose is to create a permissions plugin (so I don't need to use v-if="$isAllowed('edit', 'comments')" syntax)
I've looked at this and this tickets. The directive works, as in it replaces the element with a comment in the rendered DOM, however when running tests, the element still exists.
the directive:
Vue.directive('allow', (el, binding, vnode) => {
if (!isAllowed(binding.value)) {
const comment = document.createComment(' ');
Object.defineProperty(comment, 'setAttribute', {
value: () => undefined,
});
vnode.elm = comment;
vnode.text = ' ';
vnode.isComment = true;
vnode.context = undefined;
vnode.tag = undefined;
vnode.data.directives = undefined;
if (vnode.componentInstance) {
vnode.componentInstance.$el = comment;
}
if (el.parentNode) {
el.parentNode.replaceChild(comment, el);
}
}
});
Template:
...
<div v-allow="['edit', 'comments']" test-name="comment">
<!-- some irrelevant code here -->
</div>
...
The test:
it('does not render element when user has no access to it', () => {
expect(wrapper.find('[test-name="comment"]').exists()).toBeFalsy();
});
The test fails (saying component exists). However, when I print the rendered html (console.log(wrapper.html());), it prints comment instead of the component.

Vue rendering array of objects

I'm creating a basic app in vue that uses axios to make a get request to grab html data from a blog site and using the cheerio node package to scrape the site for elements such as blog title and the date posted of each blog articles. However, I'm having trouble trying to render the scraped elements into the html. Here's the code:
<template>
<div class="card">
<div
v-for="result in results"
:key="result.id"
class="card-body">
<h5 class="card-title">{{ result.title }}</h5>
<h6 class="card-subtitle mb-2 text-muted">{{ result.datePosted }}</h6>
</div>
</div>
</template>
<script>
const Vue = require('vue')
const axios = require('axios')
const cheerio = require('cheerio')
const URL = 'https://someblogsite.com'
export default {
data() {
return {
results: []
}
},
mounted: function() {
this.loadBlogs()
},
methods: {
loadBlogs: function() {
axios
.get(URL)
.then(({ data }) => {
const $ = cheerio.load(data)
let results = this
$('.post').each((i, element) => {
const title = $(element)
.children('.content-inner')
.children('.post-header')
.children('.post-title')
.children('a')
.text()
const datePosted = $(element)
.children('.content-inner')
.children('.post-header')
.children('.post-meta')
.children('.posted-on')
.children('a')
.children('.published')
.text()
this.results[i] = {
id: i + 1,
title: title,
datePosted: datePosted
}
})
})
.catch(console.error)
}
}
}
</script>
I tried declaring
let results = this
before the axios request to refer to the scope within export default, but still getting the indicator from VS Code that the scope is still within the loadBlogs function. Am I missing something? I greatly appreciate the help! Thanks!
I think your problem is that you're trying to set Property of an results array so Vue can't pick your data update. Instead you should construct new array from your parsed page and set it as this.results = newResultsArray:
loadBlogs: function() {
axios.get(URL).then(({data}) => {
const $ = cheerio.load(data)
const newResults = $('.post').map((i, element) => {
const title = $(element).children('.content-inner .post-header .post-title a').text()
const datePosted = $(element).children('.content-inner .post-header .post-meta .posted-on a .published').text()
return {
id: i + 1,
title: title,
datePosted: datePosted
}
})//.toArray() // this toArray call might be needed, I haven't worked with cheerio for some time and not sure whether it returns array or its own collection type like jQuery does
this.results = newResults;
}).catch(console.error)
}
Also it should be even simpler if you just use this.results.push({...}) instead of property assignment this.results[i] = {...} (but it is usually easier to handle whole arrays instead of inserting and removing parts of them, both are viable solutions in their respective use cases, though).
And please check out this documentation article about how Vue handles reactive updates, it describes the problem you've encountered.

Getting reactivity from watch in Vue.js

Trying to make a component in Vue.js, which first shows image via thumbnail, loading full image in background, and when loaded, show full image.
The thing which does not work, component does not react on change of showThumb flag in watch section. What is wrong?
Vue.component('page-image',
{
props: ['data'],
template:
'<img v-if="showThumb == true" v-bind:src="thumbSrc"></img>'+
'<img v-else v-bind:src="fullSrc"></img>',
data: function()
{
return { thumbSrc: '', fullSrc: '', showThumb: true };
},
watch:
{
data: function()
{
this.thumbSrc = data.thumbImg.url;
this.fullSrc = data.fullImg.url;
this.showThumb = true;
var imgElement = new Image();
imgElement.src = this.fullSrc;
imgElement.onload = (function()
{
this.showThumb = false; // <<-- this part is broken
} );
}
}
} );
Note: there is a reason why I do it via 2 img tags - this example is simplified.
Your onload callback will have a different scope than the surrounding watch function, so you cannot set your data property like this. Change it to an arrow function to keep scope:
imgElement.onload = () =>
{
this.showThumb = false;
};
See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions

Vue 2 custom select2: why is #change not working while #input is working

I created a custom select2 input element for Vue 2.
My question is: why is
<select2 v-model="vacancy.staff_member_id" #input="update(vacancy)"></select2>
working, but
<select2 v-model="vacancy.staff_member_id" #change="update(vacancy)"></select2>
not?
Since normal <input> elements in Vue have a #change handler, it would be nice if my custom select2 input has the same.
Some information on my custom element:
The purpose of this element is to not render all <option> elements but only those needed, because we have many select2 inputs on one page and many options inside a select2 input, causing page load to become slow.
This solution makes it much faster.
Vue.component('select2', {
props: ['options', 'value', 'placeholder', 'config', 'disabled'],
template: '<select><slot></slot></select>',
data: function() {
return {
newValue: null
}
},
mounted: function () {
var vm = this;
$.fn.select2.amd.require([
'select2/data/array',
'select2/utils'
], function (ArrayData, Utils) {
function CustomData ($element, options) {
CustomData.__super__.constructor.call(this, $element, options);
}
Utils.Extend(CustomData, ArrayData);
CustomData.prototype.query = function (params, callback) {
if (params.term && params.term !== '') {
// search for term
var results;
var termLC = params.term.toLowerCase();
var length = termLC.length;
if (length < 3) {
// if only one or two characters, search for words in string that start with it
// the string starts with the term, or the term is used directly after a space
results = _.filter(vm.options, function(option){
return option.text.substr(0,length).toLowerCase() === termLC ||
_.includes(option.text.toLowerCase(), ' '+termLC.substr(0,2));
});
}
if (length > 2 || results.length < 2) {
// if more than two characters, or the previous search give less then 2 results
// look anywhere in the texts
results = _.filter(vm.options, function(option){
return _.includes(option.text.toLowerCase(), termLC);
});
}
callback({results: results});
} else {
callback({results: vm.options}); // no search input -> return all options to scroll through
}
};
var config = {
// dataAdapter for displaying all options when opening the input
// and for filtering when the user starts typing
dataAdapter: CustomData,
// only the selected value, needed for un-opened display
// we are not using all options because that might become slow if we have many select2 inputs
data:_.filter(vm.options, function(option){return option.id === parseInt(vm.value);}),
placeholder:vm.placeholder
};
for (var attr in vm.config) {
config[attr] = vm.config[attr];
}
if (vm.disabled) {
config.disabled = vm.disabled;
}
if (vm.placeholder && vm.placeholder !== '') {
$(vm.$el).append('<option></option>');
}
$(vm.$el)
// init select2
.select2(config)
.val(vm.value)
.trigger('change')
// prevent dropdown to open when clicking the unselect-cross
.on("select2:unselecting", function (e) {
$(this).val('').trigger('change');
e.preventDefault();
})
// emit event on change.
.on('change', function () {
var newValue = $(this).val();
if (newValue !== null) {
Vue.nextTick(function(){
vm.$emit('input', newValue);
});
}
})
});
},
watch: {
value: function (value, value2) {
if (value === null) return;
var isChanged = false;
if (_.isArray(value)) {
if (value.length !== value2.length) {
isChanged = true;
} else {
for (var i=0; i<value.length; i++) {
if (value[i] !== value2[i]) {
isChanged = true;
}
}
}
} else {
if (value !== value2) {
isChanged = true;
}
}
if (isChanged) {
var selectOptions = $(this.$el).find('option');
var selectOptionsIds = _.map(selectOptions, 'value');
if (! _.includes(selectOptionsIds, value)) {
var missingOption = _.find(this.options, {id: value});
var missingText = _.find(this.options, function(opt){
return opt.id === parseInt(value);
}).text;
$(this.$el).append('<option value='+value+'>'+missingText+'</option>');
}
// update value only if there is a real change
// (without checking isSame, we enter a loop)
$(this.$el).val(value).trigger('change');
}
}
},
destroyed: function () {
$(this.$el).off().select2('destroy')
}
The reason is because you are listening to events on a component <select2> and not an actual DOM node. Events on components will refer to the custom events emitted from within, unless you use the .native modifier.
Custom events are different from native DOM events: they do not bubble up the DOM tree, and cannot be captured unless you use the .native modifier. From the docs:
Note that Vue’s event system is separate from the browser’s EventTarget API. Though they work similarly, $on and $emit are not aliases for addEventListener and dispatchEvent.
If you look into the code you posted, you will see this at the end of it:
Vue.nextTick(function(){
vm.$emit('input', newValue);
});
This code emits a custom event input in the VueJS event namespace, and is not a native DOM event. This event will be captured by v-on:input or #input on your <select2> VueJS component. Conversely, since no change event is emitted using vm.$emit, the binding v-on:change will never be fired and hence the non-action you have observed.
Terry pointed out the reason, but actually you can simply pass your update event to the child component as a prop. Check demo below.
Vue.component('select2', {
template: '<select #change="change"><option value="value1">Value 1</option><option value="value2">Value 2</option></select>',
props: [ 'change' ]
})
new Vue({
el: '#app',
methods: {
onChange() {
console.log('on change');
}
}
});
<script src="https://unpkg.com/vue#2.4.2/dist/vue.min.js"></script>
<div id="app">
<div>
<p>custom select</p>
<select2 :change="onChange"></select2>
</div>
<div>
<p>default select</p>
<select #change="onChange">
<option value="value1">Value 1</option>
<option value="value2">Value 2</option>
</select>
</div>
</div>
fiddle