describe(`[web-components] supportsPrefetch`, () => {
    beforeEach(() => jest.resetModules());

    const subject = () => {
        const supportsPrefetch = require('../supports-prefetch').supportsPrefetch;
        return supportsPrefetch();
    };

    test('returns false', () => {
        expect(subject()).toBe(false);
    });

    describe('when prefetch is supported', () => {
        beforeEach(() => {
            const mockLink = {
                relList: { supports: (prop: string) => prop === 'prefetch' },
            } as any;
            jest.spyOn(document, 'createElement').mockImplementation(tag => {
                return tag === 'link' ? mockLink : (undefined as any);
            });
        });

        test('returns true', () => {
            expect(subject()).toBe(true);
        });
    });
});