Test in Karma/Jasmine getModifierState

Question

How to test this method (angular):

 public detectCapslock(event: KeyboardEvent): void {
        let capsOn: boolean = event.getModifierState && event.getModifierState("CapsLock");
        if (capsOn) {
            this.capsOn = "Caps Lock on";
        } else {
            this.capsOn = "";
        }
    }

Answer 1

We can do something like this:

// Assemble
const event = new KeyboardEvent('keyup', {
  key: 'CapsLock',
  code: 'CapsLock',
  modifierCapsLock: true,
});

// Act
document.dispatchEvent(event);

// Assert
expect(component.capsOn).toEqual('Caps Lock on');

or in your case:

// Assemble
const event = new KeyboardEvent('keyup', {
  key: 'CapsLock',
  code: 'CapsLock',
  modifierCapsLock: true,
});

// Act
compoent.detectCapslock(event);

// Assert
expect(component.capsOn).toEqual('Caps Lock on');