Questions tagged [jest]
Questions related to using the `sfdx-lwc-jest` Jest test framework extension for the purpose of creating unit tests for Lightning Web Components.
88
questions
0
votes
0answers
24 views
test two events in same test case lwc jest
I have a change event on an input text box whose value will be added to an array on a click event. So two events here. How can we test array length on click action.
Error: expect(received).toBe(...
2
votes
0answers
36 views
What is a typical JavaScript code coverage for LWCs (Lightning Web Components) that are adequately tested via JEST?
I know this might get closed as being a matter of opinion, but as long as those opinions are based on actual experience, such answers are valuable to me, particularly if they are somewhat consistent.
...
0
votes
0answers
25 views
With LWC Jest, how to mock custom components
I'm trying to unit test my LWC which has another custom component as child. I tried to use the steps describe in this post :
import { createElement } from 'lwc';
import EfxProjectReport from 'c/...
2
votes
2answers
43 views
Jest unit test fails for a property when it is not tagged by @api
That is a chunk of the JS code
export default class CurrencyUI extends LightningElement {
@api dropdownValue = 'USD';
That is the code for Jest
it('Currency default value', () => {
const ...
1
vote
0answers
69 views
Proper way to mock svg html template in Jest?
I want to create lwc component which selectively renders svg from html template files. I wonder how to mock that templates for the needs of JEST test. Import the same templates for component and test ...
3
votes
0answers
72 views
Declaratively mocking a custom LWC in a single unit test
The approaches suggested of using jestconfig module mapper or the mocks folder work well if you have a single mock per component you are testing, but not if you have to build how your parent component ...
1
vote
1answer
80 views
LWC + Jest: Assert about what happens before a wire adapter returns data
I have a LWC with a wired function hooked up to the getFiles method in an Apex class, like this:
myLwc.html
<template>
<template if:true={showSpinner}>
<lightning-spinner
...
0
votes
1answer
43 views
Not able to access LWC decorator in Jest test JS file?
import {createElement} from 'lwc';
import NewCmp from 'c/newCmp';
describe('c-new-cmp',() => {
it('Test New cmp page', () => {
const comp = createElement('c-new-cmp',{
...
1
vote
1answer
71 views
Can we overwrite mocked values returned in LWC Jest?
I am mocking the values in a custom label using this from
https://developer.salesforce.com/docs/component-library/documentation/en/lwc/lwc.unit_testing_using_jest_patterns
import myImport from '@...
0
votes
1answer
1k views
LWC Error: Cannot set property 'textContent' of null
I have an lwc class with the following HTML:
<template if:true={showModalButton}>
<lightning-button class="right-col-button" variant="base" label={modalButtonLabel} ...
1
vote
0answers
46 views
issue in jest test
I am writing a jest for the component and and getting below error in the event:
ABS.dispatchEvent(new CustomEvent('click'));
error i am getting :
TypeError: function xyz()
{return mockConstructor....
0
votes
1answer
385 views
LWC + Jest: Mocking imperative Apex and returning a value
I'm going to do a Q&A-style entry here, since I couldn't find anything on the web describing this use case. I have seen several threads here describing how to do an empty mock on an Apex call in ...
0
votes
0answers
35 views
Expect() assertion for modal pop up in lwc test
I have an lwc component which is used for file uploading purposes.
Below is the code related to modal pop up from html mark up of the component
<template if:true={isModalOpen}>
<c-...
0
votes
1answer
233 views
LWC + Jest: Tracking calls to a child component's @api-decorated functions
I struggled with this and couldn't find anything on Salesforce StackExchange or Google covering this kind of scenario in an LWC-specific context. So I'm going to post something Q&A-style.
I have ...
2
votes
0answers
371 views
Test Class for LWC Component
I have a LWC Component which is used for record upload process.
Below is my LWC Javascript code:
import { LightningElement, api } from 'lwc';
import file1 from '@salesforce/apex/customLwcController....
1
vote
1answer
265 views
Unable to test variable value with Wire in jest
I am trying to read simple users list with wire method. However, I'm unable to test the variable value in jest promise, is there anything wrong with my code/understanding?
LWC -
@wire(getUsers)
...
3
votes
1answer
505 views
event.dataTransfer is getting undefined in JEST for dragstart
I'm trying to implement Jest tests for a module(to reorder data table rows). However, I'm unable to mimic the dragstart event. Can anyone help me to achieve the same behavior -
Here is the function ...
4
votes
1answer
726 views
Jest LWC, How to test the callback function of a registerListener?
I have a LWC component which performs multiple operations in connectedCallback(), one of them is a registerListener which calls an apex method which updates a record in the DB. Here is my question: ...
3
votes
1answer
436 views
sfdx-lwc-jest' is not recognized as an internal or external command
I am trying to run LWC Jest test, While i'm run this command:"sfdx force:lightning:lwc:test:run"
I am getting this error: 'sfdx-lwc-jest' is not recognized as an internal or external command,...
0
votes
0answers
60 views
Error for import not found in JEST test
I am trying to learn jest but , one thing is stopping me and i am not able to resolve.
I have below code in my LWC :
import testPermission from '@salesforce/customPermission/VS_Ut_li';
get testTab() {...
0
votes
1answer
141 views
DOM is not cleared between tests in lwc-jest
For some reason DOM is not cleared between lwc jest tests (I think).
What I want to test that page renders with lightning-input disabled by default and after button click it's enabled.
Test pass ...
1
vote
1answer
127 views
Cannot assert flowattributechangeevent in lwc test
I've created a lwc component that shows radio button. On Selecting the button, I call handleChange method as shown below.
<template>
<lightning-radio-group name="radioGroup"
...
2
votes
0answers
669 views
How to write jest test for lightning-datatable LWC
I'm populating the data table in the jest test successfully but when I try to select any row it comes up null which leads to this error TypeError: dataTableRow.click is not a function
this is from my ...
1
vote
0answers
336 views
createElement error in jest test case (Lightning Web Component)
Error says the component is not a valid component, or does not extends LightningElement from "lwc". You probably forgot to add the extend clause on the class declaration. Imported ...
2
votes
1answer
90 views
LWC test class failing
I have this apex wire method in an LWC Component
@wire(getCountriesData, { proposalId: '$proposalId' })
countriesData(result) {
this.wiredCountriesData = result;
if (result.data) {
...
1
vote
1answer
853 views
where to see test code coverage for lwc jest Test
I have this below test class which is testing a getPicklistValues method on a LWC component named manageCountries.
import { createElement } from 'lwc';
import ManageCountries from 'c/ManageCountries';
...
0
votes
1answer
307 views
LWC Toast Event JEST Test Issue
I have a JEST test that tests for the presence of a toast event when an exception occurs from an imperative apex call:
test('test exception path', () => {
getStatusList.mockResolvedValue(...
0
votes
1answer
169 views
How to access static resource in JEST for lighting web component
We are importing JavaScript library in lwc using static resource, I want to test component using JEst. But static resource is not rendering while running the test class ? How can I render ?
1
vote
2answers
513 views
TypeError: Cannot read property 'getElement' of null
It seems like when I have the querySelector('') set to "lightning-card" I get an error. I'm not understanding why.
TypeError: Cannot read property 'getElement' of null
19 |
...
0
votes
1answer
58 views
JEST issue - Wired Get Rec
I am writing a Jest to test Wire adapter
import { createElement } from 'lwc';
import NtnxMWDRequest from 'c/ntnxMWDRequest';
import { registerLdsTestWireAdapter } from '@salesforce/sfdx-lwc-jest';
...
2
votes
1answer
528 views
mocking getSelectedRows() method from standard lightning-datatable component's JS class in jest test not working
my LWC component under test have lightning-datatable with onrowselection event, that I want to test in jest. Here is
code snippet for component:
HTML:
<lightning-datatable
key-field=...
4
votes
1answer
509 views
LWC: Assertion error when testing @wire chain in Jest
I am trying to write Jest test for a component with two @wired calls (both bound to functions), but I get assertion error about property of second @wire call not being annotated with wire annotation.
...
1
vote
1answer
2k views
Get computed style in Jest Test
I have the following code.
Html template
<template>
<tr class="table__row" aria-hidden={isHidden} data-test-class="table-row">
<td>Cell</td>
...
1
vote
2answers
868 views
npm command not found when working with jest in LWC
I am doing this trailhead module to get started with testing in LWC.
The first step is to run below command
sfdx force:lightning:lwc:test:setup
But when I run this in terminal, I am getting a below ...
2
votes
1answer
407 views
Error: Cannot find module '@salesforce/client/formFactor' while testing my LWC
I am getting this error: Cannot find module '@salesforce/client/formFactor' when I run jest test, But it works in a scratch org.
import { LightningElement, api } from "lwc";
import ...
2
votes
1answer
147 views
In an unit test for an LWC, how can I prove a method executes periodically according to metadata configuration?
I have the following HTML:
<template>
<h1>Current price of a bitcoin in Euro</h1>
<lightning-formatted-number currency-code="EUR"
...
1
vote
1answer
460 views
In an unit test for an LWC, how can I prove an async chain is setting a value in a lightning-formatted-number?
I am trying to prove that the price is being set on the component.
I have the following HTML:
<template>
<h1>Current price of a bitcoin in Euro</h1>
<lightning-formatted-...
1
vote
1answer
624 views
In an unit test for an LWC, how can I mock out a fetch to a third party API?
I have a Lightning Web Component with the following HTML:
<template>
<h1>Current price of a bitcoin in Euro</h1>
<lightning-formatted-number currency-code="EUR"...
2
votes
1answer
98 views
LWC Testing framework
We have a really nasty problem with the LWC Jest tests. Every single test takes too much time to execute on Windows. For example, the very same tests take 5 secs to execute on Mac and over 1 minute on ...
0
votes
0answers
72 views
Pass value to select tag throw test case in lwc using jest
it('should handleSelectedValue',() => {
document.body.appendChild(selecteElement);
const selectValue = selecteElement.shadowRoot.querySelector('select[name="select-value"]');
...
6
votes
1answer
436 views
How to mock out custom labels in LWC for a DX org?
I was trying to write unit tests for some of my LWC components, however the ones that use custom labels throw the following exception
[LWC error]: Invalid operation on Element [object:vm undefined (2)...
4
votes
3answers
2k views
sfdx force:lightning:lwc:test:run not working
I have written a bunch of tests for LWC. I'm trying to run it using sfdx force:lightning:lwc:test:run but I run into:
ERROR running force:lightning:lwc:test:run: No lwc-jest executable
found. ...
0
votes
1answer
215 views
Lightning Web Component Jest testing
Hi I am trying to test my child component from the Jest test for that I am trying to fire an event but I am getting an error.
Code In Jest:
let aBCL = element.shadowRoot.querySelector(a-b-list-k');
...
0
votes
1answer
1k views
Cannot find module '@jest/globals' from 'abc.test.js'
Has anyone encountered this kind of an error? We had a bunch of jest js files that were working a few months but now are failing. Can any JEST experts help?
0
votes
1answer
1k views
Manipulating track variables in jest tests?
I haven't been able to find any examples or any super helpful info on this. I did find someone posting that track variables are not publicly available to element when you do this:
const element = ...
3
votes
0answers
695 views
LWC - Jest test for Apex calls in wired function
We have a class that calls the getRecord uiAPI and then using the result makes an APEX call to get more details from another custom object.
import { LightningElement, api, wire, track } from 'lwc';
...
1
vote
1answer
159 views
JEST Test FrameWork not able to put assertion on the basis of HTML tag
I need to put an assertion on the basis of HTML title in my JEST test
Please find the code as below:
import {createElement} from 'lwc';
import MeetingRooms from 'c/meetingRooms';
describe( 'c-...
1
vote
1answer
50 views
Jest Testing FrameWork createElement is not a method
need one help from the community below is my code for the JEST testing for one of my component.
import { createElement } from 'c/meetingRooms';
import MeetingRooms from 'c/meetingRooms';
describe('c-...
0
votes
1answer
31 views
Jest Test Implementation [closed]
Hi I need to mock the scenario as below but getting stuck as data is not getting pulled from the JSON
testDataJSon
{
"testpos":[
{
"test1": false,
"test2":true
...
0
votes
1answer
2k views
Simulate keydown event in JEST [closed]
I have an event listener in my JS controllerwhich i want to simulate in JEST case.
event listener goes like this
const element = this.template.querySelector('Something');
element.addEventListener('...
