fix(mock-doc): add html collections to document

fixes #1925

src/mock-doc/document.ts

@@ -68,6 +68,26 @@ export class MockDocument extends MockHTMLElement {
     return this.location.href;
   }
 
+  get styleSheets() {
+    return this.querySelectorAll('style');
+  }
+
+  get scripts() {
+    return this.querySelectorAll('script');
+  }
+
+  get forms() {
+    return this.querySelectorAll('form');
+  }
+
+  get images() {
+    return this.querySelectorAll('img');
+  }
+
+  get scrollingElement() {
+    return this.documentElement;
+  }
+
   get documentElement() {
     for (let i = this.childNodes.length - 1; i >= 0; i--) {
       if (this.childNodes[i].nodeName === 'HTML') {

src/mock-doc/test/element.spec.ts

@@ -53,6 +53,38 @@ describe('element', () => {
     expect(elm).toEqualHtml(`<meta content="updated" id="test">`);
   });
 
+  it('document.styleSheets', () => {
+    expect(document.styleSheets).toEqual([]);
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    expect(document.styleSheets).toEqual([style]);
+  });
+
+  it('document.forms', () => {
+    expect(document.forms).toEqual([]);
+    const form = document.createElement('form');
+    document.head.appendChild(form);
+    expect(document.forms).toEqual([form]);
+  });
+
+  it('document.scripts', () => {
+    expect(document.scripts).toEqual([]);
+    const script = document.createElement('script');
+    document.head.appendChild(script);
+    expect(document.scripts).toEqual([script]);
+  });
+
+  it('document.images', () => {
+    expect(document.images).toEqual([]);
+    const img = document.createElement('img');
+    document.head.appendChild(img);
+    expect(document.images).toEqual([img]);
+  });
+
+  it('document.scrollingElement', () => {
+    expect(document.scrollingElement).toBe(document.documentElement);
+  });
+
   it('document.title', () => {
     document.title = 'Hello Title';
     expect(document.title).toBe('Hello Title');