test(router): update scroller tests to use real objects (#40241)

The current tests in the router scroller are
[change-detector tests](https://testing.googleblog.com/2015/01/testing-on-toilet-change-detector-tests.html)
and do not ensure the correct behavior of the scroller.
This commit updates the tests to assert actual scrolling behavior of the
browser.

PR Close #40241
This commit is contained in:
Andrew Scott 2020-12-22 12:50:51 -08:00 committed by Joey Perrott
parent a55f581add
commit 112dff81b0
1 changed files with 44 additions and 33 deletions

View File

@ -10,19 +10,17 @@ import {describe, expect, it} from '@angular/core/testing/src/testing_internal';
import {BrowserViewportScroller, ViewportScroller} from '../src/viewport_scroller'; import {BrowserViewportScroller, ViewportScroller} from '../src/viewport_scroller';
describe('BrowserViewportScroller', () => { describe('BrowserViewportScroller', () => {
let scroller: ViewportScroller;
let documentSpy: any;
let windowSpy: any;
beforeEach(() => {
windowSpy =
jasmine.createSpyObj('window', ['history', 'scrollTo', 'pageXOffset', 'pageYOffset']);
windowSpy.history.scrollRestoration = 'auto';
documentSpy = jasmine.createSpyObj('document', ['getElementById', 'getElementsByName']);
scroller = new BrowserViewportScroller(documentSpy, windowSpy);
});
describe('setHistoryScrollRestoration', () => { describe('setHistoryScrollRestoration', () => {
let scroller: ViewportScroller;
let windowSpy: any;
beforeEach(() => {
windowSpy =
jasmine.createSpyObj('window', ['history', 'scrollTo', 'pageXOffset', 'pageYOffset']);
windowSpy.history.scrollRestoration = 'auto';
scroller = new BrowserViewportScroller(document, windowSpy);
});
function createNonWritableScrollRestoration() { function createNonWritableScrollRestoration() {
Object.defineProperty(windowSpy.history, 'scrollRestoration', { Object.defineProperty(windowSpy.history, 'scrollRestoration', {
value: 'auto', value: 'auto',
@ -43,34 +41,47 @@ describe('BrowserViewportScroller', () => {
}); });
describe('scrollToAnchor', () => { describe('scrollToAnchor', () => {
// Testing scroll behavior does not make sense outside a browser
if (isNode) return;
const anchor = 'anchor'; const anchor = 'anchor';
const el = document.createElement('a'); let tallItem: HTMLDivElement;
let el: HTMLAnchorElement;
let scroller: BrowserViewportScroller;
it('should only call getElementById when an element is found by id', () => { beforeEach(() => {
documentSpy.getElementById.and.returnValue(el); scroller = new BrowserViewportScroller(document, window);
spyOn<any>(scroller, 'scrollToElement'); scroller.scrollToPosition([0, 0]);
scroller.scrollToAnchor(anchor);
expect(documentSpy.getElementById).toHaveBeenCalledWith(anchor); tallItem = document.createElement('div');
expect(documentSpy.getElementsByName).not.toHaveBeenCalled(); tallItem.style.height = '3000px';
expect((scroller as any).scrollToElement).toHaveBeenCalledWith(el); document.body.appendChild(tallItem);
el = document.createElement('a');
el.innerText = 'some link';
el.href = '#';
document.body.appendChild(el);
}); });
it('should call getElementById and getElementsByName when an element is found by name', () => { afterEach(() => {
documentSpy.getElementsByName.and.returnValue([el]); document.body.removeChild(tallItem);
spyOn<any>(scroller, 'scrollToElement'); document.body.removeChild(el);
scroller.scrollToAnchor(anchor);
expect(documentSpy.getElementById).toHaveBeenCalledWith(anchor);
expect(documentSpy.getElementsByName).toHaveBeenCalledWith(anchor);
expect((scroller as any).scrollToElement).toHaveBeenCalledWith(el);
}); });
it('should not call scrollToElement when an element is not found by its id or its name', () => { it('should scroll when element with matching id is found', () => {
documentSpy.getElementsByName.and.returnValue([]); el.id = anchor;
spyOn<any>(scroller, 'scrollToElement');
scroller.scrollToAnchor(anchor); scroller.scrollToAnchor(anchor);
expect(documentSpy.getElementById).toHaveBeenCalledWith(anchor); expect(scroller.getScrollPosition()[1]).not.toEqual(0);
expect(documentSpy.getElementsByName).toHaveBeenCalledWith(anchor); });
expect((scroller as any).scrollToElement).not.toHaveBeenCalled();
it('should scroll when anchor with matching name is found', () => {
el.name = anchor;
scroller.scrollToAnchor(anchor);
expect(scroller.getScrollPosition()[1]).not.toEqual(0);
});
it('should not scroll when no matching element is found', () => {
scroller.scrollToAnchor(anchor);
expect(scroller.getScrollPosition()[1]).toEqual(0);
}); });
}); });
}); });