Converting native Karma, Jasmine tests to use Angular-Testing-Library

A great suggestion by John O. was to try Angular-Testing-Library in response to this post.

Here's the results:

1) It can still run using Jasmine and Karma per the common Angular application.
2) Here's how to install it
3) It is way more easy to use and it handled more dependencies automatically than Karma.
4) Create a simple test.spec.ts like this:


import { render } from "@testing-library/angular";
import { CheckboxComponent } from "./checkbox.component";
import { ReactiveFormsModule } from "@angular/forms";

describe("CheckboxComponent", () => {
   it("testing checkbox", async () => {
      let temp = await render(CheckboxComponent, {
         imports: [ReactiveFormsModule]
      });
      debugger;
   });
});

4) Type in 'ng test', and make sure the spec is picked up by Karma/Jasmine.
5) Press F12 when the test starts to run then take a look at the variable "temp".

Temp is the RenderResult


{fixture: ComponentFixture, debugElement: null, detectChanges: ƒ, navigate: ƒ, rerender: ƒ, …}
fixture: ComponentFixture {componentRef: ComponentRef_, ngZone: NgZone, _autoDetect: false, _isStable: true, _isDestroyed: false, …}
detectChanges: ƒ detectChanges()
navigate: (elementOrPath, basePath = '') => {…}
rerender: (rerenderedProperties) => {…}
debugElement: null
container: div#root0
debug: (element = fixture.nativeElement) => {…}
type: ƒ type(element, value, options)
selectOptions: ƒ selectOptions(element, matcher, matcherOptions)
waitForDomChange: ƒ componentWaitForDomChange(options)
waitForElement: ƒ componentWaitForElement(callback, options)
waitForElementToBeRemoved: ƒ componentWaitForElementToBeRemoved(callback, options)
queryAllByLabelText: ƒ ()
queryByLabelText: ƒ ()
getAllByLabelText: ƒ ()
getByLabelText: ƒ ()
findAllByLabelText: ƒ ()
findByLabelText: ƒ ()
queryByPlaceholderText: ƒ ()
queryAllByPlaceholderText: ƒ ()
getByPlaceholderText: ƒ ()
getAllByPlaceholderText: ƒ ()
findAllByPlaceholderText: ƒ ()
findByPlaceholderText: ƒ ()
queryByText: ƒ ()
queryAllByText: ƒ ()
getByText: ƒ ()
getAllByText: ƒ ()
findAllByText: ƒ ()
findByText: ƒ ()
queryByDisplayValue: ƒ ()
queryAllByDisplayValue: ƒ ()
getByDisplayValue: ƒ ()
getAllByDisplayValue: ƒ ()
findAllByDisplayValue: ƒ ()
findByDisplayValue: ƒ ()
queryByAltText: ƒ ()
queryAllByAltText: ƒ ()
getByAltText: ƒ ()
getAllByAltText: ƒ ()
findAllByAltText: ƒ ()
findByAltText: ƒ ()
queryByTitle: ƒ ()
queryAllByTitle: ƒ ()
getByTitle: ƒ ()
getAllByTitle: ƒ ()
findAllByTitle: ƒ ()
findByTitle: ƒ ()
queryByRole: ƒ ()
queryAllByRole: ƒ ()
getAllByRole: ƒ ()
getByRole: ƒ ()
findAllByRole: ƒ ()
findByRole: ƒ ()
queryByTestId: ƒ ()
queryAllByTestId: ƒ ()
getByTestId: ƒ ()
getAllByTestId: ƒ ()
findAllByTestId: ƒ ()
findByTestId: ƒ ()
copy: (element, options) => {…}
cut: (element, options) => {…}
paste: (element, options) => {…}
compositionEnd: (element, options) => {…}
compositionStart: (element, options) => {…}
compositionUpdate: (element, options) => {…}
keyDown: (element, options) => {…}
keyPress: (element, options) => {…}
keyUp: (element, options) => {…}
focus: (element, options) => {…}
blur: (element, options) => {…}
focusIn: (element, options) => {…}
focusOut: (element, options) => {…}
change: (element, options) => {…}
input: (element, options) => {…}
invalid: (element, options) => {…}
submit: (element, options) => {…}
click: (element, options) => {…}
contextMenu: (element, options) => {…}
dblClick: (element, options) => {…}
drag: (element, options) => {…}
dragEnd: (element, options) => {…}
dragEnter: (element, options) => {…}
dragExit: (element, options) => {…}
dragLeave: (element, options) => {…}
dragOver: (element, options) => {…}
dragStart: (element, options) => {…}
drop: (element, options) => {…}
mouseDown: (element, options) => {…}
mouseEnter: (element, options) => {…}
mouseLeave: (element, options) => {…}
mouseMove: (element, options) => {…}
mouseOut: (element, options) => {…}
mouseOver: (element, options) => {…}
mouseUp: (element, options) => {…}
select: (element, options) => {…}
touchCancel: (element, options) => {…}
touchEnd: (element, options) => {…}
touchMove: (element, options) => {…}
touchStart: (element, options) => {…}
scroll: (element, options) => {…}
wheel: (element, options) => {…}
abort: (element, options) => {…}
canPlay: (element, options) => {…}
canPlayThrough: (element, options) => {…}
durationChange: (element, options) => {…}
emptied: (element, options) => {…}
encrypted: (element, options) => {…}
ended: (element, options) => {…}
loadedData: (element, options) => {…}
loadedMetadata: (element, options) => {…}
loadStart: (element, options) => {…}
pause: (element, options) => {…}
play: (element, options) => {…}
playing: (element, options) => {…}
progress: (element, options) => {…}
rateChange: (element, options) => {…}
seeked: (element, options) => {…}
seeking: (element, options) => {…}
stalled: (element, options) => {…}
suspend: (element, options) => {…}
timeUpdate: (element, options) => {…}
volumeChange: (element, options) => {…}
waiting: (element, options) => {…}
load: (element, options) => {…}
error: (element, options) => {…}
animationStart: (element, options) => {…}
animationEnd: (element, options) => {…}
animationIteration: (element, options) => {…}
transitionEnd: (element, options) => {…}
pointerOver: (element, options) => {…}
pointerEnter: (element, options) => {…}
pointerDown: (element, options) => {…}
pointerMove: (element, options) => {…}
pointerUp: (element, options) => {…}
pointerCancel: (element, options) => {…}
pointerOut: (element, options) => {…}
pointerLeave: (element, options) => {…}
gotPointerCapture: (element, options) => {…}
lostPointerCapture: (element, options) => {…}
doubleClick: (element, options) => {…}
__proto__: Object

The RenderResult object has everything needed to access the DOM.

How do we access the DOM?

temp.fixture.componentInstance.element.nativeElement.innerHTML

Shows this:

<form _ngcontent-a-c0="" novalidate="" ng-reflect-form="[object Object]" class="ng-untouched ng-pristine ng-valid"><label _ngcontent-a-c0=""></label><!--bindings={
  "ng-reflect-ng-if": "false"
}--></form>

Or, we can pull values out of the component itself, like this; where control is an input property of the component.

temp.fixture.componentInstance.control

It's expanded value looks like this:

{GroupName: "", PropertyName: "", Type: "", CurrentValue: "", Checked: ""}
GroupName: ""
PropertyName: ""
Type: ""
CurrentValue: ""
Checked: ""
__proto__: Object

Take Away
This library seems to make configuration of dependencies much more simple.

Thanks to John O.

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Converting native Karma, Jasmine tests to use Angular-Testing-Library

John Peters

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