Testing Angular Components: Asserting that an undefined value is true

Question

Testing Angular Components: Asserting that an undefined value is true

I am a beginner in programming and I have been tasked with performing unit testing in Angular for the first time. I am feeling a bit confused... I need to test the following method in my component.ts:

isInputHidden = true;

showInput(){this.isInputHidden = false;}

spec.ts :

it('should show the input', () => {
component.isInputHidden == false;
let showInput = component.showInput();
expect(showInput).toBe(true);

})

When I run this test, I encounter these errors: In jasmine ==> Expect undefined to equal true. In Terminal ==> Argument of type 'true' is not assignable to parameter of type 'Expected'. Can someone assist me in understanding what I should modify?

angular typescript unit-testing

Answer 1

Answer №1

To solve the issue with your test, follow these steps:

Be sure to initialize your variable using =, not ==
Call the function directly (since it does not return anything, there is no need to initialize the showInput variable with it)
The variable you should test for expected results is InputHidden directly, as its value changes with the showInput() function

it('should display the input field', () => {
component.isInputHidden = false; // replace "==" with "="
component.showInput(); // the function will change isInputHidden value directly
expect(component.isInputHidden).toBe(true); // check isInputHidden status

Answer 2

To solve the issue with your test, follow these steps:

Be sure to initialize your variable using =, not ==
Call the function directly (since it does not return anything, there is no need to initialize the showInput variable with it)
The variable you should test for expected results is InputHidden directly, as its value changes with the showInput() function

it('should display the input field', () => {
component.isInputHidden = false; // replace "==" with "="
component.showInput(); // the function will change isInputHidden value directly
expect(component.isInputHidden).toBe(true); // check isInputHidden status

Testing Angular Components: Asserting that an undefined value is true

Answer №1

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