I'd like to write a test to prove a polyfill works. I'm using mocha
, chai
, and jsdom
. jsdom
exposes window.location.origin
as a readonly property so I can't force the polyfill to be used (throws TypeError: Cannot set property origin of [object Object] which has only a getter
when attempting to set global.window.location.origin = null
;
polyfill:
export default function polyfills () {
if (typeof window === 'undefined') {
return;
}
// http://tosbourn.com/a-fix-for-window-location-origin-in-internet-explorer/
if (!window.location.origin) {
let loc = window.location,
port = loc.port ? `:${loc.port}` : '';
loc.origin = `${loc.protocol}//${loc.hostname}${port}`;
}
}
jsdom setup:
import jsdom from 'jsdom';
global.document = jsdom.jsdom(
'<!doctype html><html><body></body></html>',
{
url: 'https://www.google.com/#q=testing+polyfills'
}
);
global.window = document.defaultView;
global.navigator = window.navigator;
test:
import {expect} from 'chai';
import polyfills from '../path/to/polyfills';
describe('the polyfill function', function () {
before(() => {
delete global.window.location.origin;
// polyfills(); // test still passes when this is commented out
});
it('correctly exposes the window.location.origin property', () => {
expect(global.window.location.origin).to.equal('https://google.com');
});
});
Using
Object.defineProperty
worked: