try out testing with the mock declaration in Jasmine test

Question

try out testing with the mock declaration in Jasmine test

My service involves loading a variable from a JavaScript file fetched from a CDN (without a typedef).

To handle this, I have created a declaration for the variable:

declare const externalValue: string;

@Injectable() 
export class Service {
...

Everything seems to be going smoothly until I try to test my service and encounter the following error message:

ReferenceError: externalValue is not defined

This error is understandable as the index.html file where the JavaScript file is loaded has not been called.

My question now is how can I mock this value when I am testing my service?

javascript angular typescript jasmine

Answer 1

Answer №1

To make a value accessible, you can utilize the window object:

window['externalValue'] = 'amazing';

If you are working with strict TypeScript, you will need to first extend the global window object. The global part in this declaration is not entirely necessary, but if you include it in a file that is loaded for every other file (such as polyfills.ts), you only need to declare it once.

declare global { interface Window { externalValue: string; } }

After that, you can simply do:

window.externalValue = 'even more amazing';

Answer 2

To make a value accessible, you can utilize the window object:

window['externalValue'] = 'amazing';

If you are working with strict TypeScript, you will need to first extend the global window object. The global part in this declaration is not entirely necessary, but if you include it in a file that is loaded for every other file (such as polyfills.ts), you only need to declare it once.

declare global { interface Window { externalValue: string; } }

After that, you can simply do:

window.externalValue = 'even more amazing';

Answer 3

Answer №2

To ensure certain js files are loaded in the browser during test runs, you can specify them in the karma.conf.js file. For more details on karma configurations, refer to their official documentation

files: [
   file1.js, // Include files/patterns to load in the browser.
   file2.js
]

Another option is to define a global variable within the test file.

var externalValue = "externalValue";

describe('Testing External Value', () => {
    //
});

Answer 4

To ensure certain js files are loaded in the browser during test runs, you can specify them in the karma.conf.js file. For more details on karma configurations, refer to their official documentation

files: [
   file1.js, // Include files/patterns to load in the browser.
   file2.js
]

Another option is to define a global variable within the test file.

var externalValue = "externalValue";

describe('Testing External Value', () => {
    //
});

try out testing with the mock declaration in Jasmine test

Answer №1

Answer №2

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